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Product 483008

ISP Technologies Theta 400W 2x12 Guitar Combo Amp   

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ISP Technologies introduces the 400-watt Theta Combo. Continuing the ISP tradition of innovation, the Theta guitar amp offers a unique approach to th...Click To Read More About This Product

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Delivers thunderous, stack-like performance from a combo!

ISP Technologies introduces the 400-watt Theta Combo. Continuing the ISP tradition of innovation, the Theta guitar amp offers a unique approach to the combo amplifier, putting the performance of the amazing Theta guitar system and the world-renowned Vector active guitar subwoofer technology in a single, lightweight combo package. With 100 watts RMS driving the Celestion speaker and 300 watts available to deliver the thunderous low end the Theta Combo really delivers on sound.

The Theta Combo provides 2 selectable input pre-distort preamplifiers. Using the Theta Amp is like having 2 low-noise, extremely high quality preamp pedals at the input of the amplifier. Each front-end pre-amp has gain, bass, mid level and mid sweep which provides amazing pre-distort tone shaping. The amplifier's "Clean" and "Distort" circuits have the same post distort tone shaping. Tone beyond your wildest dreams! Extreme sonic flexibility. The Clean channel has additional tone shaping with the inclusion of a Presence control providing more than 20db of high frequency boost.

You want gain? The Theta has greater than 150db of gain and you can control it and make it useable because of the included dual independent full-featured Decimator Noise Reduction systems. The Theta Combo incorporates "Dynamic Saturation Modulation"™, which delivers the actual feel of a saturated tube power amplifier. The Theta Combo also packs a huge punch; the internal D-CAT power amplifier delivers 100 watts RMS into a 12-inch Celestion guitar speaker and 300 watts into a second 12-inch, high excursion woofer. Derek Bowers, renowned IC design engineer from Analog Devices and Buck Waller of ISP Technologies, developed the patented D-CAT power amplifier technology. The D-CAT is a super high current power amplifier technology capable of driving a .5-ohm load. This means that the D-CAT amplifier delivers fantastic transient response and punch.


Theta 400W 2x12 Guitar Combo Amp

  • 400 watt RMS, two channel, fan cooled amplifier.
  • 12" Celestion (100 watts), 12" high-excursion woofer (300 watts)
  • Response to 45Hz (-10dB)
  • Weight - 70lbs
  • Dimensions - 29.9" W x 19.9" H x 14.1" D

Review Snapshot

by PowerReviews

(based on 3 reviews)

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Reviewed by 3 customers

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Theta Combo Rocks... Period.

I don't know if anyone will ever read this, but I have never been happier with an acquisition (except maybe the ISP Theta Preamp that I use for recording).

The tonal variety of this beast is unprecedented. I love crystal clear Alex Lifeson circa HOLD YOUR FIRE/PRESTO/A SHOW OF HANDS kinda guy and never did I think not running direct would do it... I can actually find that with this amp! Sweep the mids and you can get some great jazz and funk tones with a neck single coil pickup.

The sheer scope of the types of gain and tonal variety due to the mid sweep and active EQ is amazing. I can coax Mesa, Marshall, Engl and Bogner type tones out of this thing, but, make no mistake, it has a voice of it's own that is unique. You can hit a light crunch, 80's hair metal, super-saturated modern, and everything in between with mild adjustments. It's open, clear and mean.

I yanked the stock Celestion G12T-75 out of this beast and loaded it up with an Eminence Swamp Thang... holy beejeebus!!! Had a Governor in there for a bit too... just as good.

There's nothing like this amp... if you can find one, get it. You will NOT be disappointed. ISP Technologies is a great and supportive company and respond to inquiries quickly. Awesome gear, awesome company that allows me to make awesome music.

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By rabb1t34

from Texas

seriously. for the money, your not going to get a better combo. pros: this amp has more gain and low end then you will ever need (which is a good thing, especialy if your into metal). the fact that the sub is active and tuned to a guitar frequecy makes it one of a kind. you can get any tone you want with it. the decimator is unbelievable. plug in a cab and you will have the greatest tone in town.cons: the effects loop kinda sucks. no biggy. you cant turn off the decimator via foot switch. that sucks. the clean to distort volume is unbalanced. you have to turn down your distort channel and max out your clean to make a smooth change. the preamp takes some time get used too. trust me on that. and it is heavy as hell. but thats to be expected. you need a cab to hear it at a concert (if your not micd up) sorry about my poor spelling.


theta combo wow

By superfrog

from va beach

I am a bonnified tube snob and all I have to say is holy s--t. this amp is versatile with a capitol v . First off If you like tube type warmth this amp will rock you. I own mesa boogie lone star,mesa boogie f-30,uglys amps 18 watter,vintage marshall jmp, and a host off exspensive pedals to boot. This was a leep of faith for me as the sound samples do not do it justice but add a decent compressor and through a delay in the loop and you will be amazed. Isp has proved to me that intelligent design and quality parts can blow away tube amps. What cant you do with this amp. W/ the subwoofer set at a moderate setting you can get a true marshall stack feel with the real feel of air movement even at low volumes. This is something that believe me, you will never find anywhere else! If you are a tone freak seriously consider this amp. Steve Luth from Toto endorses this company for good reason. Oh and by the way I probably won't sell the mesa lone star as I am using it as a power amp for extra wattage! I'm sorry mesa but now I can get my sound at any volume in any club. As a 30 year vet of rock guitar I feel as though someone finally has made a guitar amp for me and I'm going to tell everyone about it. Please understand I don't do reviews because I'm rarely impressed but these guys are doing something different that works. If you get a chance to try this amp do it. And one more thing on the sound bytes of this amp I was worried because I didn't hear any classic rock stuff. Rest assured it does c.r. very well from eagles to vh. Try it if you can ,then sell all your useless gear and buy this amp! John Va Beach

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