A few months ago, when I was doing research on power conditioners for audio equipment, I asked a Parasound Corporation associate to recommend a power conditioner for the Halo JC 1 power amplifiers.
I was advised that:
1. The JC 1 is designed to be plugged into the wall and does an excellent job of filtering the wall AC. It is relatively immune to variations in wall voltage and noise level as long as they are within power industry specifications and standards. I later verified, with my own measurements, that the JC 1 does indeed do an excellent job of filtering the wall AC.
2. To their knowledge, there are no consumer grade power conditioners or regenerators that can meet the high current demands of the JC 1.
3. I should only consider using a power conditioner with the JC 1's if the utility company's power is excessively noisy, unreliable or the voltage is consistently too high or too low.
4. Something to remember while shopping is that a power conditioner capable of feeding the JC 1 will be a commercial grade unit and will cost considerably more than the retail price of a pair of JC 1's ($7,000).
5. Even with an adequate power conditioner and assuming the wall power is within spec, the degree of improvement will be small and comparable to that achieved with a high quality power cord. Therefore, the degree of diminishing returns will be excessive.
Excellent results were achieved by running my two channel system source components off a PS Audio Power Plant Premier AC regenerator and running my home theater system source components, plasma television, and power amps off two Power Plant Premiers. Therefore, I thought a little experimentation wouldn't hurt. I borrowed the two PPP's from my HT system and placed them between the JC 1's and the wall in my two channel system.
Aside from my personal experience running my three Adcom GFA-5500 power amps (200 wpc 8 ohms/325 wpc 4 ohms - all my home theater speakers are 4 ohms nominal.) from Power Plant Premiers, there are few references in the audio literature which discuss running higher powered amplifiers (200 watts and above) from a Power Plant Premier (PPP). I found references to a Pass Labs X250 (250 wpc 8 ohms), Bryston 14B ST (600 wpc 8 ohms), Classe CA 300 (300 wpc 8 ohms) and Krell 400 Cx (400 wpc 8 ohms) being run off a PPP. The owners of those amps said they achieved improved sonic performance with the PPP.
A PPP was installed between the wall and the right side JC 1. The JC 1 was connected to the PPP with a PS Audio Premier SC power cord (7 AWG). The PPP was connected to the wall with a Signal Cable MagicPower cord (10 AWG). Two small strips of newspaper were taped down on one end over the fan vents in order to indicate when the fans came on. Digital thermometers were placed on the heat sinks of both JC 1's and on the cooling vents over the PPP's heat sinks. A Tektronix TDS 2012 oscilloscope was connected to one of the PPP's output receptacles.
Figure 1. The right side JC 1 gets treated to regenerated AC.
When the JC 1 was switched from standby to on, the regenerated waveform peaks flattened and the output total harmonic distortion rose to slightly higher than that of the wall voltage. This indicated that the PPP could not supply adequate startup current to the JC 1 and connected it straight to the wall. When the PPP is taxed above its instantaneous current delivery capability, it connects directly to the wall and then switches back to regenerated power once the high demand is over (e.g. power amp capacitors are charged up).
Music was played at a moderate average level of 92 dB-C. The fans came on after 20 minutes and stayed on at the lowest speed. The fans were whisper quiet and I could not hear them until my ear came to within six inches of the case top. The fan speed did not increase even at a sustained sound level of 105 dB-C. The warmest the PPP vent area rose to was 100 degrees F. The PPP connected JC 1 ran cooler. Its heat sinks rose to 109 degrees F. The left side JC 1's heat sinks rose to 121 degrees F. Room temperature was 71 degrees F. The fans went off 8 minutes after the JC 1's were switched to standby.
Other PPP users have mentioned their power amps running cooler. I also noted that my home theater power amps and /preamp processor ran five degrees cooler with the PPP surface of my plasma television screen runs 7 degrees cooler (down to 87 degrees F from 94 degrees F).
Figure 2. Wall voltage sine wave form. So sad.
Figure 3. Wall voltage Fast Fourier Transform noise spectrum.
The quality of power delivered to my home is a little worse now than prior to hurricane Gustav (9/1/08). The harmonic and other noise content is higher and the power waveform peaks are flatter due to the higher noise content. Compare figures 2 and 3 above to the wall voltage sine and FFT plots taken in August of 2008, and shown in figures 6 and 7 of Residential Noise Study Part 3. Even though the power delivered to my home is noisier, I have noticed no sonic degradation through the JC 1's.
My flattened peaks of my normal wall voltage now looks like the loaded down wall voltage that used to feed my home theater system (figure 8 of the Residential Noise Study Part 3 thread).
Hurricane Gustav tore down all of the main electrical transmission lines supplying this area as well as many of the substations and distribution facilities. I actually expected the power quality to improve since we would be getting new electrical transmission facilities. However, it appears that the power company cut many corners in order to save money and restore power quickly. I'll keep monitoring the power quality periodically to see if things get back to the previous quality, but I am not holding out hope. The good thing is that my audio and video quality has not suffered since most of my gear is behind regenerated power.:)
Figure 4. PPP output sine wave plot with JC 1 connected and switched to standby.
Figure 5. PPP output sine wave plot with JC 1 connected and switched on, but not playing.
Comparing figures 4 and 5, there is a slight flattening of the left side of the waveform peaks in figure 5. The higher noise content caused by switching on the JC 1 is easily seen by comparing figures 6 and 7. The JC 1 draws 2.08 amps continuously when idling and considerably more when playing music.
Figure 6. PPP output FFT plot with JC 1 connected and switched to standby.
Figure 7. PPP output FFT plot with JC 1 connected and switched on.
The first part of the listening evaluation was done with one PPP installed on the right side. The second part was installing the second PPP on the left side. A monophonic SACD recording, Sonny Rollins' Saxophone Colossus, was used for part one.
With one PPP on the right and the balance control set in the center, there was a 1 foot leftward shift in the center images. Shifting the balance all the way to the right resulted in an apparent (but not measured) reduction in sound level and a loss of dynamics, detail, and overall clarity. It was like draping a sheet over the right speaker. The PPP's "MultiWave" setting, which extends the charging time of the sine wave peak so attached power supplies have less ripple, didn't help.
Based on part one results, I wasn't looking forward to putting the second PPP in, but I had to evaluate the PPP's in stereo mode. With both JC 1's running off a PPP, the sound stage shrank 1 foot on each side. Details at the far sides of the sound stage were greatly diminished. Images that were previously projected 3 to 4 feet in front of the speaker plane receded 3 feet. The music sounded slower. This was not fun.
Our pops told you we only like sucking power straight from the wall. Why you thought
our pops didn't know what he was talkin' about?
Pass Laboratories X0.2 Preamplifier
Pass Laboratories Xono Phono Preamplifier
Parasound Halo JC 1 Monoblock Amplifiers
Teres Audio Model 255 Turntable
Ortofon MC Windfeld Cartridge
Graham Phantom B-44 Tonearm
Cary Audio CD 306 SACD Player
Polk Audio SDA SRS 1.2TL Speakers
Audioquest LeoPard Tonearm Cable
Audioquest Sky XLR Interconnects
Audioquest Everest Speaker Cables
PS Audio Power Plant Premier Power Regenerator For Source Components
The monoliths are laughing at me because they
perceive this as a failed attempt to get a bigger
and better sound stage without buying a bigger
and better amp.