Hands-On Review:Furman Power Factor Pro Power Conditioners

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Furman Power Factor Pro Power Conditioners

Hear the Difference

By Bailey Lauer


Furman Power Factor Pro

The best investment any musician who plays through an amp can ever make is a Power Factor Pro power conditioner. The AC power that reaches your amp is typically so poor that it can muddy the sound and mask the harmonics of guitars, keyboards, and basses. Your amp may also be unable to deliver when pushed due to insufficient available power. Most local utility's power is overtaxed, prone to spikes and dips, and has high line impedance. The Power Factor Pro corrects all these power issues and immensely improves the sound of your amp.


When Musician's Friend contacted me to review the Furman Power Factor Pro, I had no idea what I was getting into. I was astonished by the sound the Power Factor Pro unlocked in my amp and I had no idea the power I fed it could really affect the sound so much. Placing a Power Factor Pro between my 100W amp and the wall receptacle was a revelation.


What's wrong with the power?


The Power Factor Pro corrects two major power problems, no matter what studio or club you play in. First, you can't depend on the power that comes through the outlet, due to power surges and other dangerous spikes and dips. Secondly, there can be a weak level of current, especially if you're sharing power with all other equipment and lights in a venue. You may not get all the current you need.


Furman's Power Factor Pro corrects the problem of unreliable power with their SMP+ (Series Multi-Stage Protection Plus) technology. The SMP+ circuit absorbs, clamps, and dissipates damaging transient voltages surge after surge. Plus, if you accidentally connect to a 220V outlet, its extreme voltage shutdown circuitry protects your gear from damage by shutting off the incoming power until it is corrected. Furman's Linear Filtering Technology (LiFT) makes your sound cleaner by dramatically lowering AC line noise across the entire audio bandwidth.


The problem of weak current is corrected by the Power Factor Pro's Clear Tone Technology. A 45-amp peak current reservoir holds plenty of power so you can be sure it's there when you need it. To understand how electricity affects your amp, an analogy between transmitting electricity and transmitting water can help. It would be nice if plugging into an outlet were like turning on a garden hose. Unfortunately it's more like pouring water through a crusty straw. But with the Power Factor Pro, the 45-amp current reservoir is ready whenever you need to blast the fire hose. With the PF-Pro, your amp isn't gasping to get the power it needs.


Sound check


I was anxious to test out the Power Factor Pros when they came in the mail. Musician's Friend sent me two versions of the Power Factor Pro and I gave them both a going over. The PF-Pro is a compact, standalone unit with four AC outlets and the PF-Pro R is a rackmountable version with one front and eight rear AC outlets and a rear BNC connector for a 12V gooseneck lamp. Both models have a 12-amp RMS capacity and a convenient 20-segment LED voltmeter to monitor incoming voltage.


Furman Power Factor Pro Rack Power Conditioner


I plugged my amp into the PF-Pro and started playing some riffs at different volumes, and the difference in sound was immediately apparent. The sonic impact was especially dramatic at medium to high volumes. My amp put out much more detailed sound through its clean and distortion channels. The dynamics, harmonics, and clarity I had been missing were unbelievable!


I took the PF-Pro R to my band's next practice session and hooked it up to our rack. We practice in a dim storage space, so the gooseneck lamp really came in handy by lighting up the whole back of our rack. It is an optional feature, but I would highly recommend getting one--it definitely beats fumbling around in the dark or holding a flashlight in your mouth.


My keyboardist and bassist were curious to try their amps through a power conditioner. The keyboard sounds were much less nasal and gained clarity, attack, and extension through the PF-Pro, while the bass sounded punchier with more weight. My guitar's scream and cry gained bite and harmonics. Together our sound was noticeably better. It doesn't take "golden ears" to hear the PF-Pro's impact.


Though I couldn't see most of the features of the Power Factor Pro at work, I could definitely hear them. However, it was interesting to see the incoming voltage with the 20 LEDs on the voltmeter, which went into the yellow danger zone a few times at our practice space and once at home. It was disconcerting to think about how long I had been feeding my amp dangerous voltage. I just never really worried about it that much, so I didn't think I needed a power conditioner. But I had no idea how much better it could make my sound in addition to protecting my gear. I wish I had tried it a long time ago.


Definitely worth it


I was so shocked by the transformation of my amp's sound with Furman-filtered power that I did some research to find out what happens inside my amp when I push it to get that signature distorted tone. When I hit a power chord, within 20 milliseconds the power supply starts to load down and drains the capacitors, potentially creating an unstable condition. With the Power Factor Pro I can get consistent distortion that won't damage my amp and there will be consistently better sound quality.


I also found out that a major factor in amp prices is the power supply, which is a big reason my amp now sounds like a much more expensive one. A classic tube amp typically has a much better power supply than an inexpensive solid-state amp. The Power Factor Pro evens the playing field, definitely making it worth the price for those of us who can't afford fine vintage and boutique amps.

Why spend lots of money on an amp just to feed it a muddy power supply? It's like fueling your high-performance car with cut-rate, regular gas. Several of the people I let test their gear with the PF-Pro or the PF-Pro R have since ordered one from Musician's Friend. It's a consensus--if you have an amp, you need this power conditioner.


  • Clear Tone Technology with 45-amps peak current reservoir
  • SMP+ (Series Mode Protection Plus) with EVS (Extreme Voltage Shutdown)
  • LiFT (Linear Filtering Technology) with zero ground contamination
  • 12-amp rating with circuit breaker
  • Front-panel incoming voltage meter from 90-128V




  • 4 rear-panel outlets
  • Floor-standing design
  • Detachable, locking AC cord

PF-Pro R:

  • 8 rear-panel outlets (4 for digital components and 4 for analog components)
  • 1 front-panel outlet
  • Compact, single rackspace design
  • Rear BNC connector for standard 12V gooseneck lamp


  • 90-140 VAC ("E" versions 180-280 VAC)
  • Over voltage shutdown: 140 VAC typically ("E" versions 260 VAC typically)
  • Voltmeter accuracy: +2 VAC, calibrated with internal trimpot adjustments
  • Spike protection modes: Line to neutral, zero ground leakage
  • Spike clamping voltage: 188 Vpk @ 3,000 amps (133 VAC RMS) (tested to UL-1449 6,000 Vpk @ 3,000 amps)
  • Response time: 1 nanosecond
  • Maximum surge current: 6,500 amps
  • Noise attenuation: 40dB @ 10kHz, 40dB @ 100kHz, 100dB @ 10MHz (linear attenuation curve from 0.05-100 ohms line impedance)
  • Transient current reservoir: 45 amps peak
  • Power consumption: 6W (resistive) 420W (reactive)
  • Safety agency listings: CE, ETL-C (pending)