Furman FAQ

Answers to the common questions we get about Furman products.


Q. Who needs a Power Conditioner? And why?

A. Every owner of quality audio/video components who wants top performance from their system, whether it's a commercial venue, a pro studio, or a residential AV system. As delivered, AC power is contaminated with noise, and additional noise is added by your everyday appliances, computer power supplies, etc. Without exception, this degrades the performance of your sensitive audio/video components. Also, electrical surges and spikes have becomes common-place, occurring on a daily basis. These and other harmful AC events put valuable equipment at risk. A good power conditioner filters and cleans incoming AC power and dramatically improves your equipment's performance. Audio sounds better and your picture looks cleaner. It will increase the longevity of your connected components since contaminated AC add wear and tear to power supplies and other internal circuits. and of course, a good power conditioner will protect your equipment from damaging AC events such as surges, spikes, lightning and high voltage.

Q. But aren't all Power Conditioners the same?

A. No, they are not! The average surge suppressor or power strip offers little in the way of protection and doesn't filter or clean contaminated power at all. However, Furman power conditioners always offer a high level of protection and purification. That's why top touring professional and major venues trust their systems to Furman.

Q. Can a 15 amp rated power conditioner be used with a 20 amp dedicated AC line?

A. Absolutely! The advantage of the 20 amp line is not just its capacity to withstand up to 20 amps RMS before its circuit breaker trips (typically in your electrical panel), but by necessity it has LOWER resistance thanks to wiring with more surface area. This is an advantage to power amplifiers, as they will always prefer a low impedance (low resistance) source.

However, very few audiophile systems and most small to moderate home theaters will never exceed 15 amps RMS. RMS stands for root mean squared, and it refers to a constant current load (not a fast current transient or peak). When an AC line or an AC power conditioner is rated for a given current input or output, the number refers to the maximum R.M.S. current draw that can be handled before the circuits breaker of fuse engages and disconnects the power source or shuts down the power conditioner.

If a 5amp, 10 amp, or 15amp power conditioner is used with a 20 amp dedicated AC line, all that will occur is that the power conditioners circuit breaker will trip when it’s maximum RMS current rating has been reached. This will in no way effect the AC line supplying the power conditioner.

Q. Can a 20 amp rated power conditioner be used with a typical 15 amp AC line?

A. Yes! Often a discriminating audiophile, videophile, or home theater enthusiast will wish to take advantage of superior filtering or other features that might be exclusive to a 20 amp rated AC power conditioner. In this instance there is a possibility of the homes AC panel circuit breaker tripping long before that of the power conditioner if the 15 amp rating is exceeded, but this is merely an inconvenience, and an unlikely occurrence unless the system draws in excess of 15 amps RMS.

Q. I understand each of my power amplifiers require a 20 amp circuit, and that my power amplifiers can draw as much as 50 amps! Won't I have a problem with a 15 or 20 amp AC power conditioner shutting down?

A. It’s VERY unlikely. What the amplifier manufacture has failed to explain is that they are concerned with peak current draw, not RMS current draw. There are very few power amplifiers manufactured regardless of price or topology that will exceed 5 amps RMS at FULL VOLUME! Typically, it’s half that amount. An amplifier manufacture is concerned about very fast current peaks that rarely last more than 20 mS! As they are concerned with the effects of current compression, they will typically as for an over sized, over rated AC supply, because they know that a 20 amp circuit will have less resistance than a 15 amp circuit of the same length. This lowers the AC impedance, and allows the power amplifiers to perform better when high volume transients are reproduced by the amplifier. An even better way to reduce the AC source impedance and improve the performance of any power amplifier is Transient Power Factor technology.

Current compression occurs when a power amplifier attempts to draw power for fast transient signals that exceed the short term capabilities of the unit’s power supply. Because of the relative inefficiency of today’s loudspeaker designs, and an ever increasing quest for greater fidelity and frequency extension, many power amplifiers routinely drain the AC power tap from your service. The percentage of voltage drop is typically small and rarely sustained for more than fractions of a second. However, this distortion is quite audible, particularly in a premium system. Often a discriminating audiophile, videophile, or home theater enthusiast will wish to take advantage of superior filtering or other features that might be exclusive to a 20 amp rated AC power conditioner. In this instance there is a possibility of the homes AC panel circuit breaker tripping long before that of the power conditioner if the 15 amp rating is exceeded, but this is merely an inconvenience, and an unlikely occurrence unless the system draws in excess of 15 amps RMS.

One of the reasons for the proliferation of after-market AC cords for Home Theater and Audiophiles is that any attempt to lower the resistance or impedance from Your AC service to the Power Amplifier will aid in reducing this unwanted compression. Unfortunately, many AC conditioners have filtering circuitry that can actually raise the incoming AC line impedance, and compromise system performance. Not so with Furman’s Power Factor Technology. By creating a reactive shunt network of sufficient size and proper tuning, the capacitors and inductors utilized will not only provide the level of linear noise suppression required for transverse mode filtering, but the circuit can actually lower the line impedance. This provides a significant increase in fidelity because the amplifiers power supply can recover more efficiently.

Q. What is Power Factor Technology? 

A. Power Factor Technology is but one of many unique Furman AC power management technologies. Specifically, it was designed to meet the needs of today's current starved power amplifiers, powered receivers, and powered subwoofers.

Q. How Does It Work? 

A. Power Factor Technology utilizes a proprietary parallel reactance circuit which stores a reservoir of energy while lowering high frequency AC impedance during transient peak operating conditions. This circuit acts like a massive "fuel tank" for your power amplifiers power supply, providing increased performance and stability with over 45 amps peak current reserve in the Elite-15 PF i, and up to 80 amps peak current from the IT-Reference 20i! This transient power factor correction technology is the same concept that is already used in many large industrial applications and in large professional power amplification systems that can not tolerate compromised performance.

Q. Why Would I Need It?

A. Today's audio sources are more dynamic than at any time in history. 30 years ago, the dominant audio medium was the pre-recorded cassette tape - a mere 15 years ago it would have been a VHS tape for a home theaters. These mediums were extremely limited. Minimal bandwidth (fewer lows and highs), and compressed dynamic range (no immediacy or presence, a lack-lustre - dull reproduction). Fortunately CD, SACD, DVD, and Blu Ray have put an end to the performance restrictions we once knew. Now everyone can enjoy the real-life reproduction that was once reserved for industry professionals and broadcast engineers alone. Unfortunately, loudspeakers are no more efficient that they were 30 years ago when they were only required to reproduce a small fraction of what they are faced with now.

To meet this demand, power amplifiers have increased in size, efficiency, and power output. Yet, most homes do not have the ultra-low AC impedance taps these amplifiers would like to have for stable, peak operation. In fact, it's for this reason most power amplifier manufacturers do not recommend plugging into a power conditioner – this is with good reason, as most power conditioner's filtering and protection circuits, by nature, increase line impedance and resistance, restricting the flow of current these amplifiers so desperately need!

When a power amplifier is reproducing audio content – particularly fast dynamic audio content with extreme transients (ie : a quiet classical piece that suddenly demands your attention with a crash and striking of cymbals and timpani, or; a loud, sudden explosion in an action film), it may need a sudden large draw of current to reproduce the signal accurately. Most amplifiers will supply this, but when they do, their power supply (particularly their power transformer) can become temporarily unstable while the supply momentarily drops to a very low impedance (nearly a short circuit for a fraction of a second). At this time, the power amplifier's supply circuit will attempt to stabilize with a large current draw from your AC wall tap. If current cannot be provided efficiently enough, the result is a phenomenon called current compression.

Current compression can result in greatly reduced fidelity, frequency response, and transient volume level of the signal that is being reproduced, leaving the content sounding boomy, flat, dull, and listless. By providing a current reservoir at the AC source immediately in front of the power amplifier, a short duration current reserve is readily available . This provides control, bottom-end extension, and increased dynamics when the power amplifier is pushed to higher volume levels.

Q. What Furman Home Theater Products Feature Power Factor Technology? (Click for answer)

A. Products include:

  • Elite-15 PF i
  • Elite-20 PF i
  • IT-Reference 15i
  • IT-Reference 20i

I can concentrate on my playing

With Furman in my rack, I can concentrate on playing – and not worry about my rig!

– Jerry Horton, Papa Raoch