Amp stands for Pass Labs

11-21-09: Bryoncunningham
This was quite different from my experience putting isolation devices under my dac/preamp, which resulted in improved clarity and focus.

Agreed 100%. I have had the most profound improvements using Grand Prix Audio Apex footers under my preamp and source.

For peace of mind, I left the isolation under the amp anyway.
Bryoncunningham (System | Reviews | Threads | Answers)

Again, agreed 100%. "It couldn't hurt, right?"

Grant

And all who have not heard a difference or very little when direct mechanical coupling their power amps.

A short story. 1998 and having owned a Essence power amp for a few years and knowing the builder Dale Pitcher [now of Intuitive Designs}and the amps general layout. Alex Gibson the designer of FMS cables told me to forward my speaker cables to Brent Riehl in Lincoln to have them re-wired shotgun style in hopes of producing more bass slam. Brent as it happened designed the original Audiopoint for use with Dale's amp in mind . The Essence amp in Corian had potted power supplys on a single board laying flat on the chassis bottom. In discussion with Brent, this of course came up and I was sent 3 Audiopoint 1.5 APs. These points were to be threaded into the 3 inscribed factory ready receptacles,lifting the power supply away from the main chassis and then coupling the supply to mechanical gound. My self installing the 3 points under a 120 pound amp all the while trying to thread them into a floating power supply was about to kill me. The pay off was big time in every way. The stage size and clarity increase was amazing and huge. The very reason I purchased this amp over many others became even more apparent with the installation of the three coupling points.

The use of the points this first time was under a power amp, directly coupled to the huge power supply inside. Since this first encounter I have direct coupled almost every power transformer and almost as many power supply capacitors, always with a positive audio result. I have performed the latest upgrade to my Wyred4Sound SE preamp removing the steel mounting bolt holding down the transformer and replacing with non ferrous brass and remounting on .2 audiopoints. Result was greater speed and detail.

Looking back in time now I have gleaned that especially a large mass as a power amp it is most imperative to direct couple the power supply mechanically and better yet couple it independently from the amplification circuit. If not the power supply resonance will pollute the wide bandwidth circuit. The power supply always comes first before the circuit it supplys. The supply is the greatest of resonance offenders and needs to be corrected first and most effectively interior and then exterior. Perhaps this in part is why the difference in improvement was not as large as one may have predicted. Tom

So, you're recommending that I unscrew the transformers in my $10,000 Pass Labs amplifiers to separate them from the chassis, and then to screw threaded Audiopoints through the bottom of the amplifier's chassis and into the transformers, thus directly coupling them to the Audiopoints?

There's no way I'm going to do that to my amplifiers. No way.

To suggest that performing this tweak, thereby voiding the manufacturer's warranty, in order to be able to hear the positive effects of $1700 Sistrum stands absolutely stuns me.

Incredible.

Don't let anyone fool you, isolating your amplifiers can make a great sonic difference. I've used three different amp stands with varying results. I'd rank them in this order: 1. Sound Anchors custom amp stands
2. Solid Steel Large amp stands 3. Auralex Gramma speaker and amp stands.

I know all 3 stands can enhance the sound over just sitting them on the floor. I don't know the reason others cannot hear the difference. The bottom line, try a pair, Music Direct will sell you a pair to try for up to 30 days. If you don't hear a differnce, send them back.

Have fun!

Huh,

I said no such thing either by description or by your suggestion have I ever done such a thing. I never accomplished any such feet/feat so completely except for that first time with the Essence amp because it was designed so completly to do so from the factory. The reason that I brought up the Essence was to describe the experience of separately coupling the power supply to ground from the main chassis and "that factory design" would be superior to the following. All other mods I performed were to couple the transformers of any other audio device directly to their own chassis,not independently. And those uspeakable mods could be performed by any thoughtful designer to everyones benefit, including to the Pass by Mr.Pass. You do not have to screw thru the chassis to do so, you simply put unthreaded points and coupling discs between the transformer and the existing chassis and replace the factory supplied steel screws that screw with the field of flux with non ferrous materials as described in published text books from a few hundred years ago. All other factory built power supply mounting methods I have seen are inferior to the method applied by Mr.Pitcher and Mr.Riehl just over ten years ago. Tom