Furman Power Elite 15 PFi Listening Impressions

Featured image courtesy of Furman Power. This is the Elite series over-voltage protection board.

The Furman Power Elite series of power conditioners features a modular design that easily allows Furman to offer products with differing capabilities. Furman Power offers 3 versions of the Elite 15i

  • The Elite 15i is the base version with series over-voltage protection, extreme voltage protection, and linear filtering of line noise. This device includes an AC voltmeter showing line voltage.
  • The Elite 15 DMi provides the same power conditioning but adds a second meter showing the current being drawn. This is of interest if the outlet or the Elite 15 is heavily loaded. You can identify the straw breaking the camel’s back
  • The Elite 15 PFi removes the meters and adds power factor correction to the standard protection functions.

References

  1. https://youtu.be/Mx7yky2C9Gk Seasick Steve with Jack White at South By Southwest. “Overdrive” Steve puts Jack White’s PA in thermal protection.

Elite 15 PFi Listening Impressions

The Elite 15 PFi appears not to affect the sonic character of the equipment used with it. My initial impressions of the Elite 15i adding a lush character were based on listening to a Live From Here playlist that happened to be particularly well recorded. As I listened to more of my catalog, I realized that Furman Power Elite series products were transparent, adding no color to the sound as you would expect of a power conditioning device.

How Musician and Home Products Differ

The Elite 15 PFi and Elite 15i are alike in this regard. Both are transparent, well engineered and well built devices. Furman Power makes things for the music professional and their home products and pro products differ only in their interface capabilities. Pro products follow the control standards in use in professional studio and stage equipment. Home products follow the control standards in use in the professional home sound installation market.

Power Factor Again

The Elite 15i and Elite 15 PFi are similar inside. The two share the basic power conditioning boards. The 15 PFi removes the metering board and adds the components needed for power factor control.

Large audio amplifiers used in the touring and installed sound markets have power factor control built in to the amplifier power supplies. Tour and installation equipment operators are trying to get as many watts of audio as is possible out of a given mains line  rating. Power factor control does this by bringing AC current draw into phase with the AC voltage. When this condition is satisfied, the current draw for a given power is minimized. A very useful capability for the touring musician.

Why I Chose the Elite 15 PFi

I opted for the Elite 15 PFi because I have an older ’70s stereo amplifier (GAS Ampzilla) built before soft starting power factor controlled switching power supplies. The inrush currents were rough on both the amplifier and the mains wiring. I wanted to tame the inrush currents and take care that the amplifier was not doing strange things to the mains at power as this circuit is shared widely in my mid ’50’s modern ranch house. Both the Elite 15i and Elite 15 PFi appear to serve well at taming the amplifier inrush current on start up.

Instrumentation is required to observe the  effects of the 15 PFi on the mains draw. It should act to smooth it out as the machine contains a large electrolytic capacitor like those used in air conditioning starting circuits that takes part in the power factor correction. This capacitor releases stored energy to the amplifier when needed and catches stored energy released from the amplifier as amplifier and dynamic loudspeakers interact during complex musical passages.

Thoughts on Breaker Tripping

The Furman manual contains cautionary statements about breaker tripping on heavily loaded circuits. This is not the fault of the Elite 15 PFi. Rather, the user is skating too close to the edge of the mains breaker rating. This is not an issue at home but is probably encountered in touring sound operations.

Breakers have time-current trip characteristics. The higher the over-current, the quicker the breaker trips. When the circuit is running at rated draw, for extended periods, breakers using bimetal thermal overloads are already warm and are closer to their trip point. When presented with a sustained moderate overload, they will trip.

What I think is happening is that touring companies are overloading the company panel circuits. With start-up sequencing, they can get everything going. When things get loud, they discover that the line is over-subscribed and the breaker pops. This happened to Seasick Steve at SXSW in the reference video. Heavy sustained overdrive got either the mains breakers or the amplifier thermal protection in the PA amps.

Basically, you can connect a couple of 2 KW amplifiers to a 15 amp circuit Soft-start will get them going without tripping the breaker. Most of the time, the average current draw will be well below the 15 amp rating. Then a sustained loud passage comes along. Current draw rises above 15 amps, and the breaker trips.