Buying Guide:Preamps Buying Guide

  1. 1. How To Use This   Guide
  2. 2. What is a   Preamp and What Does it Do?
  3. 3. Do You Need a   Preamp if You Have a Mixer or Audio Interface?
  4. 4. "Color" vs.   Transparent Preamps
  5. 5. Preamp Types by   Circuit Design
  6. 6. What is a   Channel Strip?
  7. 7.   Transformerless/Transformer–Coupled
  8. 8. Understanding   Applications > Intelligent Selection
  9. 9. Should You Buy a Preamp or Channel Strip?
  10. 10. The Benefits of Owning More than One Preamp
  11. 11. Applications for Different Types of Preamps
  12. 12. Should You Choose Mono, Stereo, or Multi-Channel?
  13. 13. Preamp I/O
  14. 14. Preamp Features
  15. 15. What Do the Specs Mean?
  16. 16. Choosing a Preamp — What to Look For

1. How To Use This Guide:


Related Content

  Preamp Glossary

  DI Buying Guide

  DI Glossary

  You Don’t Show Me No ReSpecs

So High It Hertz

  History Of The Channel Strip

  Origins of Phantom Power

You’ll no doubt notice that this buying guide is quite long. In  reality, it’s quite short in relation to the numerous books and articles  written on the subject. To accommodate your needs as best as possible,  we’ve created three ways of navigating this guide (four if you count  clicking through the table of contents).


First, for those who subscribe to the philosophy, “when in doubt,  know everything,” just read through from beginning to end and check out  the sidebars along the way. Second, for those who want more of an  overview and basic insights, we have the Fast Track. Just start reading  and along the way you’ll find the icon at paragraph  headings or in the body of text. This will permit you to  click through the important issues of preamp selection without reading  all of the details. Of course, there’s no reason why you can’t stop,  view more details, then jump back on the Fast Track. Third, we have the  Faster Than Light Drive , which takes you straight to a list of preamps and their applications without any of the theory.


Get on the hyperspace byway now and make the jump to lightspeed.


You Need To Ask Yourself a Question . . .


Before you can decide which preamp or channel strip is best suited to  your musical vision, you have to ask yourself a question: Do I feel  lucky? (Sorry, having a Clint moment there…) Actually there are a number  of questions you need to ask yourself, which should take luck out of  the equation, that is, once you know your options. So, before you sit at  the feet of Swami Snatch-your-dineros, audio guru extraordinaire, or  listen to countless assertions without proof, we’ve designed this buying  guide to provide insights, answers, and a little history about what  happens on the other side of the glass — and while a little  techno-babble is good for the soul, we’ve also set about the task of  demystifying and clarifying the specs and jargon, because sometimes the  big numbers don’t necessarily mean better sound.


Remember that there are near infinite paths to audio nirvana. A  little knowledge will take you a long way, but in the final analysis, it  will be your ears and budget that will determine which path you end up  taking.

2. What Is a Preamp and What Does It Do?


You’ve heard the term pre-school? Basically, it takes a low-level  intelligence (a person whose last job description was “Embryo”) and  brings them up to spec in order to attend regular school. A preamplifier does much the same thing to audio  signals before they go to a power amp or recording equipment.

In essence, the preamp’s job is to take a low level signal, possibly  from a guitar pickup, mic, or turntable etc, and amplify it to line level. Technically speaking, the preamp provides  voltage gain but no significant gain in current. That makes a  preamp good for recording applications, but if you want to actually hear  the signal, a power amplifier must follow. The power amplifier provides  the higher current and voltage needed to drive loudspeakers. (A guitar  amp incorporates both a preamp and power amp in one housing.)


Even though preamps appear to be utilitarian devices, they also cross  over into the creative realm of music in terms of the sound quality  they impart to a given signal. One preamp may excel at recording guitars  and vocals, while another may be better at audiophile or orchestral  recording.


Preamplifiers come in various forms. They can be built as a standalone  unit, or integrated into a modular system such as a recording  console or standalone channel strip (see What is a Channel  Strip? below). The standalone channel strip is based on the console  channel strip, which combines a preamp with other signal processing  circuits including EQ and compression. (More on that later.)



3. Do You Need a Preamp If You Have a Mixer or Audio  Interface?


If you own one of today’s affordable mixers that promises performance rivaling more  expensive consoles, or use an audio interface with DAW recording software and  processing plug-ins, you may wonder why we would  recommend buying an external preamp to record through. The answer is  simple. While these mixers and interfaces have successfully brought  studio recording to the masses, some corners had to be cut in order to  keep the prices down. In fact, even with world-class recording consoles,  in order to keep prices down, the first place manufacturers would slash  and burn was in the preamp section. This is one reason why using  outboard preamps became a standard practice in the studios.


Aside from that, in a console, the signal has to travel through a  number of circuits, switches, amplifiers, busses, controls, patch  points, etc, until it reaches the output. Each one of these detours  degrades the signal to some degree, and once degraded, it cannot be  restored. Recording direct from the preamp to recorder offers the  clearest, most detailed, and punchiest sound. Even Mr. Rupert Neve,  creator of the legendary $1.2 million Focusrite Forte mixing desk has stated that the best  recording path is the simplest — from mic to pre to recorder. Besides,  there just isn’t enough room in a console’s channel strip for a tube  design or the sophistication of today’s external preamps. Meanwhile, it  certainly stands to reason that you won’t get the same sound quality  from a $3,000 mixer as you would from one costing a million, which makes  the need for a good outboard preamp that much more essential. To be  fair, numerous hit records have been recorded exclusively on such  consoles, but today, they are more often used for mixdown and monitoring.


With digital workstations, the audio interface takes the place of the  routing and monitoring functions of a mixer, and while they may contain  preamps, they are usually not the focus of the unit. For professionals  working with DAWs, the use of a quality analog front end bypasses the lesser preamps of the audio interface and adds  character to the inherent sterility of digital recording.


The beauty  of adding a high-quality preamp or channel strip to your setup is that  instead of paying, $4,000 per channel times 32 for a pro-quality  console, about $2,000 to $3,000 buys you a “gold channel” for your DAW  or mixer that you can use to record track by track. That’s one of the  secrets of having world-class sound on a project studio budget. If you  need to record more simultaneous channels, there are a number of  high-quality multichannel preamps available from PreSonusGrace  Designs, True  Systems, Millennia, and others.



4. “Color” vs. Transparent Preamps


While there are several categories of preamps in terms of circuit  design, aesthetically they can be divided into two main groups. Those  that impart a distinct timbral characteristic to a sound are commonly referred to as “color” preamps.  Those that deliver a signal that remains as true as possible to the  original source material are referred to as being “transparent.” You’ll  usually find both types in most studios to meet a range of recording  needs. For example, a color preamp can add body or character to a thin  voice or instrument, whereas a transparent preamp strives to reproduce  the sound as accurately and true to life as possible.


Groove Tubes ViPre

Color Designs


In rock and pop recording, the idea is to make the music sound larger  than life, and more importantly, sound unique. This is where you’ll  find more color preamps in use. The people who subscribe to this school  of thought tend to be mavericks with more of an “anything goes” outlook.  That is to say, whatever gives you the sound you’re looking for,  whether it’s hi-fi or lo-fi, then that’s what you use. Preamps that fall  into this category are generally tube and solid state, transformer-coupled designs. Examples include the Universal  Audio Solo/610, Groove  Tubes Vipre, Tube  Tech MP1A, Trident  S40, and A  Designs Audio Pacifica.


Transparent Designs


Grace Designs 101

On the other hand, there are producers and engineers engaged in  audiophile recording who firmly believe transparency is the only way to  go. The audiophile school believes that there should be as few active  components as possible in the signal chain in order to achieve the best  possible and most realistic recorded sound. To the super-tweaks, the  best preamp would be a straight wire with gain. Shy of that, they seek one  that offers the shortest signal path possible from input signal to  recorder. Generally, these folk will prefer solid state, transformerless  preamps. Such preamps are built by companies including MillenniaGrace  Designs, True  Systems and Audient


It’s Not a Clear-Cut Case of “Us” and “Them”


Remember, transparent does not equal sterile! George Massenburg  (designer and builder of equipment found in top mastering studios) is  perhaps the foremost proponent of transparent equipment, yet he produced  rock and pop music. His belief is that you can’t mix or EQ properly if  you can’t hear the actual sounds you’ve recorded. Besides, if the  instruments already sound good to begin with, then you’ll want to  reproduce them as accurately as possible without electronic artifacts  (or at least as few as possible). It is also possible for solid state  preamps to emulate the sound of tube pres, which has been proven by the  aforementioned Mr. Neve, Joemeek designer Ted Fletcher, and others.


It’s All You

Keep in mind that electronics will always add or take away something.  The only true acoustic reproduction is done by your ear. When you think  about it, any sound that’s picked up by a microphone, converted to a  voltage and then sent through preamp, EQ, compressor, digital converters, and ultimately out to  loudspeakers is going to be affected in one way or another. As such, an  audiophile recording of an acoustic guitar or grand piano by definition  is actually electronic music. In the final analysis, it’s the sound that  is most pleasing to your ear that matters.



5. Preamp Types by Circuit Design


Tube Preamps


A-Designs MP-2a
A-Designs MP-2a


Generally preamp design falls into two main categories, tube and  solid state. Tube preamps, as the title implies, employ thermionic tubes  (or “valves” as the Brits call them), to create gain. Tube preamps fall  mainly into the “color” category and are known for their ability to add  character, midrange presence, deep bass and an upper frequency response  that is described most often as “open and “airy.”


In discussions regarding the desirability of tube preamps, you’ll  often hear the words “warm” and “fat” used incessantly, but what do they  really mean? Let us clarify. It helps if you understand how tubes  function. First, as signal level increases, the tube produces mild distortion,  which in turn produces the body and depth that the word “warmth” is  meant to describe. Since the distortion is produced gradually in  measured amounts, it is pleasing to the ear. Going deeper, the  distortion itself takes the form of second- or even-order  harmonics, which are considered to be more “musical.” Here’s why:  Harmonics are component pitches of a fundamental tone that sound at  whole number multiples of the fundamental. Musically speaking, the  second-order harmonic forms the interval of a perfect octave. The octave reinforces  the fundamental tone, similar to the effect known as doubling. That’s where the word “fat” comes in since  octave doubling results in a broader sound with more depth. (“Beefier”  is another word used to describe tube preamps by engineers and  producers.) Even-order harmonics allow for pleasing distortion (much  like power chords on guitar) since they don’t produce the dissonant  pulsing (intermodulation) caused by odd-order harmonics.  The addition of even-order distortion via tubes equals color.


Another factor that contributes to the musicality of tube designs is  their natural compression characteristics. If you were to look at the  output waveform of a tube preamp, the curve at the top of the  wave becomes gradually compressed as more gain is applied (or the tube  is overdriven). This natural compression is also more pleasing to the  ear. In the mastering stages of professional recording, compressors that  utilize tube compression such as the classic Fairchild 670 (which can  go for $30,000 on the vintage market) are still sought after for the  “audio glue” they apply to a mix, giving it that finished-record sound.  Yet another natural function of tubes is to act as low-pass filters, which  smoothes out distortion in the high end of the spectrum and somewhat  reduces high-frequency content. This can  be desirable or undesirable depending on your sonic goals in a given  instance (e.g. desirable for warmer vocals, undesirable for percussion,  where attack information is  essential).

Solid State Preamps

Avalon AD2022

Solid state preamps employ transistors or op-amps to  achieve gain, which do exactly what tubes do, only more efficiently and  with less heat. As opposed to their tube counterparts, transistors  operate more consistently as gain is applied. Solid state devices  maintain very low distortion right up to their maximum level, beyond  which they distort in the extreme (called clipping). This is  actually a good thing since solid state amplifiers can provide excellent  performance when operated at maximum gain. The result is a more  accurate capture of the input signal. This is why solid state devices  are called transparent. Since solid state devices will accept much  larger gain increases prior to distortion than tubes, you can record  hotter signals without distortion.

While tubes have achieved cult status as being more “musical” than  solid state components, there are also solid state preamps that are  renowned for their sonic signature, such as those made by Mr. Rupert  Neve, the grandfather of pro audio. (Like the aforementioned Fairchild,  vintage Neve preamps such as the 1073 still fetch many times their  original price.) According to Mr. Neve, when transistors came into  being, he simply thought of them as just another form of component and  set about the task of understanding their characteristics in order to  apply them in musical context. Apparently he was successful, as the  inherent musicality of Neve gear has become legend in professional  audio.

Hybrid Preamps; The Best of Both  Worlds?

Summit 2BA-221

Recently, hybrid designs have emerged that combine both solid state  and tube components. The Summit  Audio 2BA-221 is an example. It uses solid state circuitry for the  input stage with an output gain control that drives a tube. This design  aims to combine the faster transient response and clarity of solid state  devices with the ability to add the rich second-order harmonics of tube saturation as seasoning.



Focusrite Liquid Channel

Modeling Preamps, the Best of All Worlds?


The latest development in preamp technology is modeling, which also employs solid state circuitry,  while “warmth” and other abstract sonic qualities are added in  digitally. In the case of the Focusrite  Liquid Channel, convolution processing is used in  conjunction with actual physical changes in the analog circuitry. The  result is the ability to mimic the sound of virtually any preamp and  compressor, tube, solid state, or otherwise, in any combination. While  some purists feel that there is no substitute for the real thing, the  Liquid Channel has found a home in many top studios. Of course, since  the Liquid Channel combines both preamp and compressor models, by strict  definition it’s considered a channel strip.

Digital Preamps


Apogee Trak 2
Apogee Trak 2

Basically, we’re talking about a preamp that combines analog input  with A/D/A conversion and digital outputs for recording direct to a DAW,  bypassing the DAW’s converters. Some preamps offer an optional digital  output card that can be installed by the factory or by the user, such as  the Focusrite  ISA 428, while others feature digital conversion and output  integrated into the preamp’s design, such as the Apogee  Trak2 and the ART  Digital MPA. These preamps could also fall under the category of  audio interface, however, the main focus of these units is their preamp  sections. This is not to say that the digital section is of lesser  quality — Apogee is known for making some of the best digital converters  in the indus— the distinction is regarding function. Perhaps it would  be more accurate to say “preamp with a built-in audio interface.”


Instrument-Specific Preamps


Marshall JMP-1

Here we have a category of preamp that can also be categorized as an  active DI (see the What  is an active DI? section within our DI Buying Guide.) Generally  when we say “preamp” we’re really thinking “mic amp,” with an instrument  input added as a secondary convenience. With the myriad tones available  for electric guitar and bass, certain manufacturers have created  preamps that cater specifically to the impedance requirements of these instruments without additional circuitry. For  example, the A  Designs Audio REDDI, while categorized as a DI, is actually a tube  preamp designed primarily for bass guitar. Many of these preamps fall  under the category of modeling preamps and include guitar- or  bass-oriented DSP effects that can include distortion and modulation effects, plus  speaker cabinet, mic, and amp modeling. The advantage of an  instrument-specific modeling preamp is that you can have the tone of a  specific guitar amp manufacturer such as Marshall, available for direct recording without having to buy an entire amp and additional DI to send the amp’s  output to your DAW or console. If you recall our first  paragraph, we stated that a guitar amp has both preamp and power  amp. For examples, see Instrument-specific  Preamp/DIs below.



Certain mic preamps can also be instrument specific. For example, the  EM-Blue preamp from the aforementioned A Designs Audio is designed to work best  for miking snare drums and electric guitars. This is achieved with the  selection of input and output transformers. The number of coil windings  and type of wire used in the transformers will emphasize certain  frequencies. For example, nickel wire brings out high frequencies. The  advantage to selecting preamps such as those from the EM-Series is that  the knowledge that comes from years of experience in selecting the right  preamp for specific instruments is “built-in” for you.



Trident S80 Producers Box

6. What Is a Channel Strip?


Basically, you can consider any preamp with additional signal  processing circuits to be a channel strip. The channel strip of today is  a standalone unit that in its most common form comprises a preamp, equalizer, and  compressor/limiter . Some channel strips offer variations on that theme such as preamp and  EQ only, or preamp and compressor only, while others offer additional  sections such as a de-esser or enhancer. In  short, a channel strip can offer all the signal processing tools you  need in one box.


Initially the console channel strip grew out of the need for  convenience. When most recording was done in the major studios,  engineers didn’t want to spend the extra time connecting various units  together. Besides, with the clock ticking away at $250+ an hour, a  sneeze would cost a producer about five dollars, and $50 for quick trip  to the bathroom. This was the single most important reason for the birth  of the home project studio. (See History of the Channel Strip sidebar.)



Millennia Origin STT-1
Millennia Origin STT-1

In terms of component use, channel strips tend to employ hybrid or  solid state designs. For example, the Millennia  STT-1 combines both tube and solid state circuits, as does the Universal  Audio 6176, while the Focusrite  ISA430 Producer Pack is solid state only.



7. Transformerless/Transformer-Coupled


Just as some people rally round the PC flagpole and others pledge  their troth to Mac, approaches to circuit design evoke similar  reactions.

The reason we are singling out this particular component, or lack of  it in a preamp’s circuitry is because this is mainly where the  difference between color and transparency lives. Transformer-coupled  designs sound beefy and tend to be punchier (often referred to as the  “big iron” sound of the ’70s) than the transformerless preamps. Since  all transformers color the sound of a preamp, designers in search of an  uncolored, true-to-life reproduction of sound prefer to eliminate them  from the circuit path.


Tranformerless Advantages


Due to the reduction of active components in the signal path, this is  a desirable design feature in the realm of transparent preamps. A  transformer will always add a level of coloration to a signal, and as  such, a design employing transformers cannot rival the transparency of a  well-designed transformerless input, particularly in the upper range of  the frequency spectrum. (We’re talking audiophile degrees here.)  Transformerless designs are more prevalent in solid state preamps.  Transformerless tube designs do exist but they tend to be very expensive  since they are more difficult to build than their solid state  counterparts. Major proponents of transformerless design are John La  Grou (Millennia Media and George Massenburg (GML).



Millennia HV-3D
Millennia HV-3D

Benefits of Transformers


As we said in the introduction, the function of a preamp is to take a  low-level signal and increase it to line level. The  function of a transformer is to bridge the input section of the preamp  to the output section while increasing signal voltage. The transformer  does this by virtue of magnetic coupling. Because there is no hard  wiring between input and output thanks to the transformer’s magnetic  coupling, they offer better circuit protection and the benefit of true  electronic isolation, which results in minimal noise or hum when  connected with other equipment. So you see, they’re not all bad. In  fact, certain classic solid state transformer designs are still highly  sought after for the coloration they impart and command quite a price on  the vintage market. The important issue in a transformer-coupled design  is the quality of the transformer, which is why manufacturers such as A  Designs Audio and PreSonus (for the ADL  600 have them custom made.



A Designs Pacifica
A Designs Pacifica



As you can see, there are no absolutes. Electronics is a study in  tradeoffs. There’s no reason to reject one design or another out of hand  based on design theory. We suggest you listen to examples of both  designs and see what your ears tell you. If you like the sound of a  particular preamp, whether or not it uses transformers becomes  irrelevant. It’s much like choosing a guitar. If you want a Les Paul,  you simply accept that is has a set-in neck even if you prefer a bolt-on  neck. Conversely, if you think that a set neck is superior, but want  the sound of a Fender Stratocaster, then you accept the bolt-on neck.


8. Understanding Applications = Intelligent  Selection


Hopefully by now, you have an idea regarding which type of preamp you  may wish to select, but for those on the fast track, lets just get  right into to the meat of the issue and discuss the advantages and  applications of tube and solid state devices. This should help narrow it  down for you.


Advantages and Musical  Applications of Tube Preamps:

Tube-Tech MP 1A


When character, body, or a thicker sonority is required, particularly  when vocals or instruments are thin sounding, a tube pre does the  trick. If for artistic reasons, you want a thicker sonority for  instruments in general (wall-of-sound rock guitar, bass, string samples,  synth pads, violin, etc.) the tube preamp is a good choice here as  well. Examples include the Universal  Audio 2-610, Tube  Tech MP1A.


When is “analog warmth” too much? If you’re recording instruments  that are already rich in the midrange and  lower midrange, without a prominent attack, you might find that a tube  pre can cause the sound to be a little too thick. Since we take spatial information from highs, the tube pre’s natural  tendency to act as a low-pass filter, smoothing or reducing high  frequency information might make an instrument already lacking in  high-frequency content sound a little smeared or indistinct in its  placement in the stereo field. Conversely, a tube preamp can also be  used to tame sounds that are too prominent in the high-frequency range. A  well-designed tube preamp can also sound open and “airy” in the high  registers, so again, nothing is written in stone. Do not, however,  expect a tube preamp to be as quiet as its solid state counterpart, as  tubes emit more thermal energy, which translates to noise.


Advantages and Musical Applications of Solid State


Since solid state preamps have a faster transient response and better  high-frequency response (this is where instrument  attack and spatial information lives), you’ll most likely want to use  them on drum  overheads and instruments with percussive attacks (piano,  acoustic guitar, etc.). Basically, in any application where you want  more detail and transparency, the solid state preamp will be your best  friend. You can also use them to effectively bring out instruments or  vocals in a mix that are dull and lack detail. (While tube preamps can  be detailed and accurate in the highs, this is generally where solid  state rules.) If you want transparent audiophile-quality recording, a  high-quality, transformerless solid state preamp such as the Millennia  HV-3D and Grace  Designs M801 are excellent choices.


It is important to keep in mind that solid state preamps are not  limited to transparency. Certain solid state, transformer-coupled  preamps are also capable of producing a rich, colorful sound. Examples  would be the Avalon  AD2022, A  designs Audio Pacifica, and the Focusrite  Red 8.


Focusrite Red 8
Focusrite Red 8

Hybrid or Modeling


If you are unable to afford both a tube and solid state preamp, you  might do well to consider a hybrid design, such as the Summit  2BA-221. It combines solid state input circuitry with an adjustable  gain tube output, which enables you to add some second-order harmonics  to the signal. Another possibility would be the Millennia  Origin STT-1 channel strip, which offers a choice between tube and  solid state, transformer-coupled, or transformerless operation in  virtually every audio function. While it’s more expensive than the  Summit 2BA-221, it’s one investment that may well cover all your  recording needs for a long time to come. Of course, to most recording  engineers and producers, preamps are like potato chips — nobody can have  just one. For those who prefer numerous tonal options in their palette  of audio colors but can’t afford a vintage outboard gear museum, a  modeling channel strip such as the Focusrite  Liquid Channel is the next best thing.


9. Should you buy a Preamp or a Channel Strip?


Again, this is not so much an either-or situation as much as it is a  matter of what coincides with your recording needs, philosophy regarding  sound, and of course, budget.


Channel strips offer certain practical advantages including  convenience and cost effectiveness. With your signal processing tools  all in one box, you don’t have to spend time setting up and patching  separate components together. (This is the concept behind the recording  console, from which channel strips are taken.) Let’s say you’re  recording vocals. Normally you’d use a preamp, a compressor and a de-esser.  Rather than buy three separate units, a channel strip can give you all  of those functions in a single box for much less than it would cost to  buy the units separately.  On top of that, say you want the British rock  sound of a Trident console or SSL desk, then buying a channel strip  such as the Trident  S80 or the SSL  Xlogic Super Analogue Channel is just what the producer ordered.


Solid State Logic Xlogic Super Analog Channel
Solid  State Logic Xlogic Super Analog Channel


On the other hand, if you’re recording acoustic instruments or  orchestral ensembles where accuracy and detail are essential, a channel  strip might not be your first choice. Those engaged in audiophile  recording would likely select a preamp with no other devices or circuits  in the signal path for the cleanest possible acoustic reproduction.  That concept also holds true for pop music. Additionally, using a preamp  alone allows you to save other signal processing for mixdown. For  example, if you record vocals or instruments with EQ applied, the sound,  which may have been great on its own, might not sit well in the final  mix. You may find yourself trying to cut the very frequencies  that you originally boosted. The same applies to compression,  reverb, delay, and other effects. That’s why engineers tend to save  those types of signal processing until the mixdown process.


Channel Strips with Selectable Signal Paths


Another factor to consider is noise. Since all of the  signal-processing sections of a channel strip are combined in one  matched unit, the chances for self-noise and hum from ground loops are  minimized as opposed to the greater possibilities for noise that may  occur by combining separate units from different manufacturers. But  there’s another side to that coin. By using a preamp only and saving  signal processing for mixdown, the ground loop issue is negated. It may  also be argued that compared to a preamp, a channel strip will have more  noise along with some signal degradation as audio passes though each  processing section, even if they are unused. With that perspective in  mind, some channel strips, such as Focusrite  ISA430 MKII allow you to use the preamp or EQ sections  independently of one another, taking an output before the unused  component for the shortest possible signal path to the recorder.


Focusrite ISA430 MKII
Focusrite ISA430 MKII

Digital Recording Considerations


Since 24-bit recording enables the engineer to be less concerned over  recording levels (see our Buying Guide Computer Recording:  Getting Started for more information), many prefer to record  without compression. In this case, going direct from the preamp will  provide the cleanest possible signal path. Once in the digital  environment, additional signal processing can be done with plug-in  emulations of outboard signal processors.


Some engineers prefer to record vocals with mild compression. In that  case, wouldn’t it make sense to use a channel strip? Yes, provided you  like the sound of the channel strip and that it works well with the  singer’s voice. But what if it doesn’t? Having different preamps allows  you to find the one that’s best suited to the source material. The  advantage of separate components over a channel strip is the ability to  mix and match different units for unique sounds, specific purposes, or  to use them individually to process already recorded tracks. For  example, many engineers prefer to use one particular compressor or EQ  with different preamps. More importantly, certain signal processors have  become industry standards for the sound they impart to vocals, guitars,  or drums. For example, the Teletronix  LA 2A limiting amplifier and Universal  Audio 1176LN compressor have been studio standards for decades on  vocals and drums respectively. In other applications, you may find that  an all-tube compressor is absolutely magical when combined with a  particular solid state preamp, and a dismal failure when combined with  another tube preamp (hypothetically speaking). Going back to the analogy  of the guitar, a Les Paul will sound differently when played through a  Marshall stack as opposed to a Fender Twin Reverb combo amp. Your choice  depends on the requirements of the music. The same concept holds true  for preamps and signal processing equipment.



To sum up,  by offering both preamp and signal processing in a single unit, a  channel strip is convenient, cost effective, and can offer the  “signature” sound of a coveted console. The advantage of a preamp is  that if provides shortest signal path to a recorder and the ability to  mix and match them with other processors for unique sounds, specific  recording purposes, and the possibility of creating your own signature  sound. Ultimately, your application will determine which you use in a  given setting. Sometimes, you may want to use a preamp and nothing else  (say for recording acoustic guitar) while at other times, the channel  strip will provide precisely what you need (recording vocals, for  example). Finally, if your budget doesn’t allow for separate components,  start with the best channel strip you can afford. If you just need to  get a signal into a recorder or DAW and plan on processing digitally,  get the best preamp you can afford.



10. The Benefits of Owning More than One Preamp


Mics respond differently when matched to different preamps. This is  mainly due to loading and gain characteristics unique to each preamp. Each possible  combination of mic, preamp, and source material offers its own unique  sonic possibilities (some good, some not so good, some absolutely  magical). The near limitless sonic possibilities are a primary reason  why outboard gear has become so popular among the more creative  engineers and producers. Also, from reading the above applications, it  becomes obvious that a good studio should have both colored and  transparent preamps.



11. Applications for Different Types of Preamps


For example, you may be recording a singer/acoustic guitarist whose  voice is a bit thin. You could add a little body to the voice with a  color preamp (tube) such as a Tube  Tech MP 1A or a PreSonus  ADL600. For the acoustic guitar, let’s assume that it has a  mahogany body, which would make it rich in the midrange. You wouldn’t necessarily want to add more  harmonic content, as it may muddy the sound of the guitar. A transparent  preamp with excellent transient response such as a Millennia  HV-3C or GML  2032 (both solid state tranformerless) may be just what the doctor  ordered. Creative engineers and producers think of each preamp and mic  combination as another color with which to paint a sonic landscape. For a  painter, one color is a blank canvas. Fortunately, there’s the  advantage of instruments providing their own distinct sonic image, so  until you can afford a rack of preamps, you can get by. However, if you  only “paint” in one color, you lose the contrast and variation that  gives a mix dimension and a life of its own. Plus, if all you own is a  color preamp, you may find that your recordings suffer from too much  color.


If you can’t afford more than one preamp, or don’t see yourself  owning more than one (just wait, you’ll get bitten by the gear bug soon  enough!) a preamp with “tone” switches such as the Groove  Tubes ViPre and A  Designs Audio MP-2A can offer enough tonal variation to keep your  recordings interesting.



12. Should You Choose Mono,  Stereo, or Multi-channel?

(Fast Track users, select appropriate category and continue at  section 13.)

Is Your Studio Just for Overdubbing?

Universal Audio 2-610

If you’re just going to record yourself (or a guest artist) one track  at a time, then a mono unit  will suffice. For example, if you’re a guitarist-vocalist whose backing  tracks will be created virtually via sample players, virtual synths, or  audio loops, you’ll only need one channel. Keep in mind that if you wish  to add a little sonic spice to stereo keyboards, or record your amp or  acoustic guitar in stereo for some spatiality, you might consider a  2-channel or stereo preamp/channel strip. Even virtual instruments or  stereo samples could benefit via re-amping through a 2-channel or stereo preamp. Besides, better more than less,  we always say.


Will You Be Recording Multiple Tracks  Simultaneously — Studio or Remote? (If not, get on the Fast Track)


True System P-Solo

If you plan on recording miked drums, rhythm sections, horn sections,  or full bands, then you’ll need a multichannel preamp. There are a  number of rackmountable 4- and 8-channel preamps such as those made by Audient FocusriteMackieNadyMillenniaGrace  Designs, and SMPro  Audio. If you are doing location recording and need more than eight  preamp inputs, certain 8-channel units such as those by PreSonus or Studio  Projects can be cascaded or expanded to offer more input channels.  For those who can’t settle on a fixed number of channels, some  manufacturers have come up with a clever solution in the form of  application-specific single-channel preamps, such as the A  Designs EM series, that can be cascaded in groups of up to eight in  specially-designed open racks. This offers a great solution for a  growing studio. As your need for channels increases, you can add preamps  as you go.


Do You Want More Inputs for Your DAW?


If you don’t plan to do remote recording but would like to expand  your DAW’s capability to handle more simultaneous microphone inputs, a  multichannel preamp would be a welcome addition. For example, if you own  a Digidesign Digi 002 and would like more mic inputs, an 8-channel  preamp with an ADAT lightpipe or FireWire output is just  the ticket. Examples would be the Focusrite  OctoPre, the PreSonus  DigiMAX 96, and the Audient  ASP008-ADAT



Audient ASP008
Audient ASP008

13. Preamp I/O (Input/Output)

An integral part of preamp selection is to know what type of input  and output connectors you’ll need. A combination of XLR and 1/4"  outputs will pretty much take care of most input configuration you’ll  come up against. Some preamps also have digital outputs or option cards  for digital output, but then we tread into the realm of digital audio  interfaces. For this guide, we’re going to keep everything analog — nice  and simple. (See our Computer Recording:  Getting Started buying guide for more information about audio  interfaces.)


Balanced and Unbalanced


Balanced I/O is generally preferred,  particularly in high-end preamps, due to its noise canceling properties.  In some cases, you will find unbalanced inputs and outputs in pro  equipment. They are used mainly for instrument inputs, effects loops  (which allow you to send to other signal processors), and outputs that  mirror the main outputs for connection to mixers or audio interfaces  (used for zero-latencymonitoring with DAWs). Unbalanced cables  can be used with balanced I/O without problems, provided that the length  of the cable is relatively short. With longer cables you’ll want to go  balanced. Overall, your best bet for a noise-free system is to go with  all balanced I/O.




Most preamps offer a back-panel switch that allows you to select  between these two operating levels. These are the voltages that have  been determined for consumer (-10dBV) and professional gear (+4dBu ) to  operate for optimal performance. The main difference between the two is  that the +4dBu operating level of professional equipment provides more  headroom and allows for longer cable runs without signal degradation. As  a result, power supplies for professional equipment are much more  expensive. In properly designed equipment, there is no appreciable  difference in sound quality between –10dBV and +4dBu systems — unless  you are trying to use very long cable runs at the –10dBV setting.


All of your equipment should be set to the same operating level. If  you’ve set your system to operate at +4dBu and you have a unit that only  outputs at –10dBV, that’s where the switch comes in handy. Otherwise,  you may find that you don’t have enough gain. Conversely, if you try to  send a +4dBu output into a -10dBV input, you’re going to have overload  and distortion problems.


Digital I/O


Digital outputs on preamps (usually provided by digital option  cards), come in a number of varieties. AES/EBU is a  professional standard that can take the form of 3-pronged circular XLR  jacks or 9-pin connectors (Focusrite  ISA 428 digital option card). S/PDIF Sony/Phillips Digital Interface), which can  take the form of a typical RCA  connector connector or optical port, is generally considered to  be a consumer format. Keep in mind that AES and S/PDIF refer to a data  transmission scheme, which is why the hardware can take different forms.  For example, on the Focusrite ISA 428 digital option, the 9-pin AES  format can be switched to S/PDIF. ADAT lightpipe, an  optical format developed by Alesis, can transmit eight channels of  audio. TDIF (TASCAM Digital Interface) can share the same format as ADAT, but only  transmits two channels. TDIF also comes in a 25-pin form (D-sub), which can be found on the Apogee Trak2. Some  digital preamps also have FireWire outputs, such as the Presonus  FireStudio, which features eight preamps, but this is where the  line between preamp and audio interface begins to blur. Another type of  digital I/O to be found on preamps are BNC connectors that  transmit digital clock information (Word Clock).  Again, this falls more in the realm of audio interfaces.


14. Preamp Features

Below you’ll find some of the most common features found in preamps.  Keep in mind that certain features may be necessary, while there are  others that you may occasionally or never need (usually there’s a  workaround for those.) Rather than go for an extensive features list,  you might want to sink more of your dollars into sound quality. Certain  manufacturers take this into account when they design and leave out  features that by virtue of their position in the signal path may  compromise sound slightly. To some preamp makers, the features are the  specs, but in this guide, we choose to separate the two since not all  specs determine sonic performance.


Variable Impedance


The classic example used to explain impedance is to think of water  flowing through a hose with a nozzle. With the nozzle wide-open or  completely removed (low impedance), water flows freely, but with less  force. As the nozzle is closed blocking the flow of water (higher  impedance) resistance to the water stream is increased resulting in more  force accompanied by a hissing sound (high frequency). In terms of a  mic connected to a preamp, higher input impedance means greater maximum  output for the mic and more high-frequency content. It also reduces  distortion and provides noticeable improvement in transparency. A basic  rule of thumb is to make sure that the preamp’s input impedance is at  least five times higher than the mic’s output impedance. Variable  impedance lets you dial high-frequency content up or down, as you  desire. This serves two purposes. First is the ability to EQ your input  signal without adding another unit into the signal chain, thus  maintaining a purer signal. Second, you can improve the performance of  your mic by increasing the preamp’s input impedance. One reason for this  is because microphones exhibit different output impedances at different  frequencies. The higher the input impedance, the less effect the  variations in output impedance will have on sonic quality.


Phantom Power


This is an area where your “winging-it” and Fast Track privileges are  suspended. In conventional DC-Polarized condenser mics, phantom power supplies the voltage required to  polarize the mic’s transducer element (capsule). It is called “phantom”  power because the supply voltage is effectively invisible to any  balanced microphone. Phantom power supplies the voltage through  microphone cables to power condenser mics, so if you plan on using a  condenser, the question of whether or not you need it is already  answered. Beyond that, you need to know if a preamp’s phantom power  supplies the correct amount of voltage and enough current for your mic.  Most condenser microphones require phantom power in the range of 12-48  volts DC, with many extending the range to 9-52 volts DC. Contrary to  popular myth, increasing the phantom power does not improve sound  quality. The mic’s electronics never “see” the voltage direct from  phantom power, but there are exceptions. For safety’s sake, just stick  with the recommendations by the mic’s manufacturer.


Phase Reverse/Polarity Reverse Switch — What Is It, Do You Need It?


This switch can be handy if you’re working with multiple mic setups  as far as checking for phase cancellation or improperly wired mic  cables. If you’re just going to record with one mic at a time, then you  won’t need it. On the other hand if you plan on using your preamp’s DI  to record a direct signal along with a miked signal (such as a bass),  then a phase reversal switch is  necessary. Phase reverse is actually  a bit of a misnomer, but we’ll use it since it has become an accepted  term. This is a topic that causes a bit of confusion since a signal that  is 180 degrees out of phase can appear to be the same as a signal whose  polarity is reversed. Phase is a time-related phenomenon that can only be  measured when two signals are present (AC) whereas polarity is the  simple reversal of positive to negative in one signal (DC). On a preamp  or mixing console, the switch actually reverses polarity. Its function  is to correct 3-pin XLR (balanced) cables that are wired backwards (pin 2  & 3 are cross-wired). While this can be a useful feature for stereo  recording, a phase switch in the signal path will add some coloration  to the signal. Hence, audiophile enthusiasts may prefer a preamp without  it. If you subscribe to the transparent school of recording and require  a polarity reverse, simply wire a cable “backwards” (swap pins 2 and 3  on one end of the cable) and put some red tape on it — vo— instant  polarity reverse without adding switches to the signal path.


Pad — What’s It For?


If you have a high-voltage input signal that’s causing your preamp to  distort, a pad will attenuate or reduce the signal to manageable  levels. Of course using a pad means a tradeoff in signal to noise ratio,  but in anything shy of audiophile recording it’s not terribly  significant.

DI — Hi-Z Instrument Input


Many preamps offer a convenient front-panel 1/4" input for direct  recording of a guitar, bass, or other instrument. This feature is  particularly useful for a number of situations, such as combining a  miked bass cabinet with direct sound or processing a clean guitar signal  with plug-ins. Certain high-end preamps don’t offer a DI since it is  difficult to get circuits designed to operate at +4dBu to handle the  lower power requirements of unbalanced instruments. Many engineers  prefer a high quality, dedicated DI for instruments. (See our DI  Buying Guide)




This allows you to combine or link (cascade) two mono preamps or  channel strips into a stereo or multi-channel setup. This is a good  feature if you have a mono preamp or channel strip you really like and  want to add more of the same model to your studio as budget allows. It  also provides the opportunity to add multi-channel or stereo signal  processing as you go (with similarly equipped units). Examples would be  Summit’s 2BA-221  preamps and TLA-50  compressors or the Focusrite  Liquid Channel (channel strip), which includes signal processing.  Chaining gives you the capabilities to perform stereo recording or  mastering to a final two-track mix.

Gain control: stepped vs. infinite.


Gain controls are either infinite or stepped (also known as a stepped  attenuator). A stepped attenuator lets you come back to an exact  setting. This is particularly useful for mastering applications, precise  stereo matching between channels, or matching volume when overdubbing  on tracks you’ve previously recorded (provided you’ve written all down  your settings). Infinite controls offer more precise setting capability.  For example, if the gain you need is between two positions, are gong to  tell a singer to back off the mic by a fixed amount or sing softer?  Probably not. Your particular recording needs will determine which gain  control method is better for you.



In order to manage your levels, preamps provide some form of visual  feedback. These can be in the form of LEDs that show when a signal is near or about to clip, or VU (Volume Unit)  meters, which are designed to respond to signals in much the same way  our ears do. VU meters show average levels, and are not really useful  for providing accurate information about transient and peak levels —  that’s what the LEDs are for. True VU meters are more commonly found on  the high-end preamps, while the less expensive units have VU-like meters  that actually measure decibels. The volume unit corresponds  to the decibel only when measuring a steady sine wave tone. As far as a  make-or-break feature goes, true VU meters are not one of them. In  reality, a simple LED overload indicator will suffice. Sometimes we  can’t actually hear the overloads, which if otherwise not detected, will  have a negative impact on your sound somewhere down the road.


M – S Decoding — What/— Do You Need It?


Not recording in stereo? Hit the bricks.


M - S is short for mid-side, which is a mic placement technique for  stereo recording. The advantages of mid-side recording are mono  compatibility, which actually provides a more cohesive stereo image, and  greater control of the amount of stereo information (widening or  narrowing the stereo field). And you don’t need a pair of matched stereo  mics. Not many preamps feature this, and an M-S decoding (sum and  difference) matrix is easily created in a DAW or mixer with phase  reverse. If you work in multi-mono (overdubbing), obviously it’s not  necessary, however, if you’d like to add “being there” feel and impact  to your recordings, then you may consider a preamp with this feature.  You’ll find M-S decoding on preamps such as the M-Audio  Octane and Grace  Designs Lunatec V3. Some manufacturers such as Millennia make standalone MS decoders.


15. What Do the Specs Mean?


As Einstein once said, “A little knowledge is a dangerous thing. So  is a lot.” Nowhere is this more true than in the world of specs (with  the possible exception of building nuclear weapons). Specification  listing is an area of consumer and professional electronics that can be  the most misleading under the guise of providing objective measurements  of performance. We don’t  deny the importance of specs, but they must be handled with care. There  are certain specs that if given in the proper context can be very  helpful in choosing a preamp. In many cases, however, it is nearly  impossible to use the specs to compare units, since the conditions used  to obtain the data are often omitted. For example, if you see  one preamp’s dynamic range listed at 118dB while another is listed as 122dB, it would be  natural to assume that the bigger number is better. Not so. By itself,  122dB tells you nothing. Without reference to what bandwidth was  measured or whether or not weighting filters were used, you simply have a  number but no idea what the number is relative to. Hence, there’s no  way to accurately compare. We’ve also seen a number of different ways  that manufacturers express the same spec, which makes comparisons that  much more difficult and confusing. Can we clear it all up for you? Not  really, unless you’d like to take a four-year course in electronics, but  if you’re interested in a greater understanding of how the specs are  arrived at and what they may or may not be telling you, please see our  sidebar “You  Don’t Show Me No Respecs.” There are certain specifications that  are useful in preamp selection, which we discuss below. There are also  specs that objectively measure of a preamp’s performance but offer no  clue as to sound quality. These specs include THD, slew rate, frequency  response, and phase response. Several units can have precisely the same  numbers, yet sound completely different. To put it in musical terms,  it’s like trying to learn harmony by analyzing Bach chorales on a  blackboard. Without audio examples, the rules are meaningless. The same  holds true for preamps. Unless you hear the unit you really can’t judge  its performance. In that regard, your ear is the Supreme Court. (With  Musician's Friend’s 45/45 Double Satisfaction Guarantee, you’ll have 45  days from purchase to audition the preamp before deciding that it’s  right for you.)


Specs That Can Determine Performance

Maximum Input Level (Input Headroom)


Basically, this tells you if the output voltage of your mic while  capturing loud sound sources is going to overload your preamp. In order  to calculate this, the specs you need to know are the mic’s sensitivity,  which is usually (but not always) given in mV/Pa (millivolts per  Pascal), and the preamp’s maximum input level or input headroom The problem is to convert  sensitivity into a maximum output voltage, which requires quite a bit  of math, or a lookup table that plots sensitivity vs SPL with a resultant voltage expressed  in dBu. From there, you can easily check the maximum input level of the  preamp, which is also given in dBu. Keep in mind that sensitivity is a  worst-case scenario. If a mic’s max SPL handling is 140dB (a jet engine  at 10 feet) but you’re not going to record a source louder than 110dB (a  chainsaw at three feet), then you can relax a bit. This is as close as  we can give you to a rule of thumb: The sensitivity of most condenser  mics hovers somewhere between 10 to 25mV/Pa, which at 130dB SPL  (threshold of pain) will yield a maximum output voltage of anywhere from  –2dBu to +6.5dBu. Most mic preamps should give you at least +10dBu of  headroom. Your main use of a condenser mic will be vocals, acoustic  instruments, and distance miking (drum overheads), which will certainly  keep you well below 130dB SPL. For close-miking of loud sources such as  kick drums, snares, and guitar and bass amps, you’ll mainly be using  low-sensitivity dynamic mics. The only  time you really need to concern yourself with this spec is if you plan  on buying a specialty mic such as the DPA 4003, which has a sensitivity  of 40mV/Pa, which is twice that of the average studio condenser. Even  that mic can be used effectively with most preamps as long as you don’t  put it up in front of a high SPL source. Again, you have to trust your  ears. The best overall advice we can give you is to buy the best preamp  you can afford.


Frequency Range


In electronics, musical pitch is dealt with in terms of frequency,  which is measured in Hertz (Hz). In essence, this is the range  of your preamp’s “hearing.” Frequency range is commonly displayed as  follows: 20Hz – 20kHz (k – x 1000,  20kHz = 20,000Hz). In reality, even though we can hear down to about  14Hz, not much happens in music below 40Hz save noise and rumble, and we  can’t hear above 20kHz (with 17kHz being the most common upper limit  for human hearing). So why is it that you see high-end preamps with  frequency ranges as low as 4Hz and as high as 150kHz and beyond? While  it is proven that there is acoustic content above 20kHz that is  discernable, most mics and monitor speakers are limited to around 20kHz.  The reason for designing beyond human hearing has to do with better  phase alignment of frequencies in the audible range. (Please see  sidebar: “So High it Hertz,” for an in-depth explanation by John La  Grou, founder of Millennia Media). The same thinking also applies to the  lower frequencies. In short, a wider bandwidth makes for a better  sound.




EIN stands for Equivalent Input Noise. There are different types of  noise that electronics are subject to, but the two that we are most  concerned with are thermal noise, which all components produce, and  noise from circuit resistance. Microphones have a source resistance  (impedance) that generates noise. An amplifier also generates noise from  its components and circuit resistances. When these two noises, the  external and the internal noises are added together, we have an   “Equivalent Input Noise”. However, this measurement by itself doesn’t  really tell you exactly how good the preamp is. Basic rule  of thumb: a tube preamp is going to have more thermal noise than solid  state, however with any good design, the EIN value is going to be quite  small. A preamp with a very low EIN value would be your choice for  critical recording and mastering. A tad more noise is negligible and  expected if you’re recording heavy rock and desire the coloration that  comes with tube preamps.


CMRR (Common Mode Rejection Ratio)


If you’re not using long cable runs, get in the fast lane.


In long cable runs, noise becomes an issue.  Cables can pick up radio  frequencies (RF) and other interference, which is why balanced cables  are used for their noise-canceling ability. CMRR defines to what degree  signals are canceled at the input of a balanced system. If you plan on  using very long cable runs or are in an environment where  electromagnetic interference (EMI) is an issue, make sure the preamp has  a sufficiently high CMRR. The number is expressed in dB, but in order  for this spec to make sense in terms of comparing it to other preamps,  it must be stated at a given frequency. For example, 65dB by itself  doesn’t tell you anything, however, >65dB @ 10Hz-22kHz tells you  something about the preamp’s ability (pretty good in this case) to  reject noise over a given frequency range. In most cases, you’ll see the  spec given at one specific frequency (e.g. 40dB @ 1kHz), which gives  you a basis for comparison. It is also assumed that this holds for all  input levels.

Maximum Gain


This is one of the few specs that is fairly straightforward. Certain  specialty mics have specific gain requirements. For example  low-sensitivity ribbon mics require a great deal of gain in order to  work their particular brand of magic. One problem with the way that this  spec is shown has to do with whether or not the gain rating is based on  balanced or unbalanced input and output, which can differ by 6dB  (usually balanced or unbalanced input doesn’t affect gain), but it does  affect output gain. If your heart is set on owning a ribbon mic, then  you should be looking at preamps with a gain range of 60-70dB.

Preamp Buying for FTL (Faster Than Light)  travelers


16. Choosing a Preamp — What to look for

Just as certain songs can cross over into other genres, the sound  qualities and uses of preamps can overlap. Below you’ll find some  generalizations that will help you narrow your search.

By sound quality:

  1. I  want a rich, creamy sound — Choose a tube preamp.
  2. I want  a “colored” sound that will jump out of the speakers — Choose a solid  state, transformer-coupled design.
  3. I want  transparency and accuracy above all — Choose a solid state  transformerless.
  4. I want  good transient response and accuracy first, and be able to add warmth  second — Choose a hybrid, modeling preamp.
  5. I want  as much tonal variety as I can get — Choose modeling, hybrid, or any  preamp with variable impedance or tone controls.

By application:

  1. I’m recording heavy rock and pop vocals. I  want to add character or grit — Choose a tube or transformer-coupled  solid state preamp.
  2. I’m  recording electric guitars and bass — any preamp type will do. Read  through numbers 1-5 above to decide where to look. A mono preamp will  suffice; a Hi-Z instrument input  would be a good feature to include. Instrument-specific preamps and DIs  will also work.
  3. I need  a preamp for recording drum overheads and percussion — Choose  two-channel solid state: transformer design if you agree with #2 above,  transformerless if #3, and hybrid if #4.
  4. I’m  recording great vocalists, orchestral instruments, and live jazz. I want  as true to life sound as possible — Choose a transformerless solid  state, 2-channel, or multichannel preamp.
  5. I need  a preamp to mic a drum kit —Choose a four- (kick, snare, overhead) or  eight-channel solid state preamp with ADAT lightpipe or D-sub analog  output (also, see letter C).
  6. I’m  going to record my band live — Choose a multi-channel solid state preamp  with chaining feature (cascadable).
  7. I’m  just recording my voice and acoustic guitar live — Select a 2-channel  preamp. Any of the above preamp types will w— your ear rules here.
  8. I’m  recording electronic keyboards — keyboards can be recorded direct,  however, if you want to add color, select a stereo tube or solid  state/transformer design. Most keyboards have a mono output, but a  2-channel or stereo preamp lets you take advantage of the keyboard’s  stereo presets.

Choosing your preamp


To help you choose, we’ve` divided color and transparent  preamps/channel strips into examples from manufacturers who are most  known for one type or the other. However, some manufacturers make  preamps/channel strips that fall into both categories, which we also  list below. Some makers specialize in tube or solid state designs, but  we won’t make those distinctions here. That’s what our website detail  pages are for. We’ve also included a section for budget preamps. To be  honest, rather than color or transparency, affordability is what they  are most known for. These manufacturers produce preamps of both  varieties, and despite the low prices, can produce surprisingly good  results. If you’ve gotten to this point (even on the fast track) you  should know enough about preamp design to determine if a budget preamp  will give you color or transparency. Happy hunting!


Preamps & Channel Strips by Category



Preamps/Channel Strips

Transparnent and Color
  • Apogee
  • Audient
  • Grace Designs
  • Millennia Media
  • Mindprint
  • True Systems
  • A Designs Audio
  • Avalon
  • Blue
  • dbx
  • Drawmer
  • Groove Tubes
  • Joemeek
  • Oram
  • PreSonus (ADL 600)
  • Toft Audio Designs
  • Trident
  • Tube Tech
  • Universal Audio

  • Aphex
  • Focusrite
  • Millennia Origin STT-1
  • Millennia TD-1
  • Solid State Logic
  • Summit


Guitar & Bass Preamp


Electric Guitar
Acoustic-Electric Guitar
Bass Guita
  • DigiTech
  • Hughes  & Kettner
  • Koch
  • Line  6
  • Marshall
  • Randall
  • Rocktron
  • B-Band
  • BBE
  • Fishman
  • LR Baggs
    • Aguilar
    • Ampeg
      • Ashdown
      • BBE
      • EBS
      • Eden
      • Fender
      • Tech 21
      • T-Rex


    Budget Preamps



      • ART
      • Bellari
      • Behringer
      • Electro-harmonix

    • M-Audio
    • Nady
    • PreSonus
    • Rolls
    • Studio  Projects
    • Symetrix