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power line conditioners...

When I worked in high end audio, our guru placed a 120v-120v transformer (heavy duty -- 1000va) between the wall socket and the power amp in the system being auditioned. This was just before power line conditioners became available as audio system accessories.
I found a Sola 500va 120-120 transformer in the trash and tested it -- it worked. I tried it between the wall socket and my power amp. The sound stage opened up. Also, bass was tighter and more authoritative. I felt like the high end was also clearer. I am using a Dynaco st70 in triode mode driving Kef 102's, a dynaco PAS-3X, a VPI MK-IV turntable with an Alphason HRS-100 arm, various cartidges, and a Micromega Stage3 cd player. As my room is rather small, I don't feel the need for a sub-woofer now.
I wonder if any of you other members have any experience with PLC's, or Sola 120-120 transformers? And if you have any thoughts on why the sound is improved. Could it be simply reduction/elimination of voltage fluctuations coming from the wall, or are there other things happening like availability of stored energy in the transformer for musical peaks or transients?
Another question that I have is how are the audio-specific PLC's different than a 120-120 transformer? Are they different? Are they worth the extra money?
After hearing the differences that the Sola made, I am convinced that there is something to be gained from power line conditioning. I just don't understand it very well now, and would like to!
Cheers!
bicycle_man
psacanli
535 posts
 
The Equitech site has info on balanced transformers and MITs site has some papers on noise reduction.
ngjockey
1,042 posts
 
An iso tranny also presents an inductive and capacitive load, when shielded, which should sound familiar with passive XO's. They can eliminate DC offset but aren't fond of it and can hum in protest.

The general rule of sizing, in our case, is that an iso tranny should be rated for double the maximum draw of the electronics to prevent saturation. They do not, or should not, provide ground isolation because, by code, the ground should be continuous. However, they do provide common mode (line to ground) filtration. Normal mode (line to neutral) noise is transferred through, to some degree, but most power supplies handle that in the rectifying process.

They are best used independantly as in one for CDP, one for preamp, etc. They are a defacto standard in hospitals and many industrial/laboratory applications where they prevent noise from going back into the line. Step-down transformers are common in all commercial buildings and have dual purpose.

The difference between toroidal and EI-core is mostly packaging. Toroids are less prone to mechanical hum but are not quite as effective as a filter.
magfan
1,583 posts
 
My Panamax PC came with a small iso transformer. Very good results, and even the TV had a better picture, with none of the hash present from the untouched power line.
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drummermitchell's avatar
drummermitchell
262 posts
 
I agree with Bob,They are quite amazing.i have Two Torus Pius
a 20a Balanced(components) and a 60a balanced(power amps).
they definately are Huge upgrade,
If your audio dealer will let you try one at home,
I'm sure you won't send her back.The music rides out with
authority,better bottom,no noise whatsoever.I think you would
very pleased with one.Speaking of bikes,this is the way I can describe the Torus.

You've been riding a honda 90 for quite some time and then
a friend lets you try out his Harley 1200,the power,control,
Authority.It been the best conditioner I have purchased yet
and have went with a couple of top names,but this leaves them in the dust.If I ever sell off any components,These won't be going,Totally,musically satisfied.
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