Posted by kelley on April 17, 2003 at 09:25:56:
In Reply to: Re: Re: Re: Re: Good god.... posted by Ed Piearce on April 16, 2003 at 16:28:31:
A transformer volume control (TVC) does a few things. First, as it reduces voltage it decreases the output impedence for a given source impedence or increases the input impedence for a given load (unlike resistive passive preamps). This reduces its sensitivity to interconnects and/or reduces the load on the source. Second, it provides isolation and breaks up potential ground loops (assuming you don't connect the input and output grounds). Third, it can go from any combination of balanced and unbalanced to any other combination of balanced and unbalanced.
Remember small signal transformers do not have to contend with some of the saturation and other issues that output transformers face. The S&B Tx-102 transformer is within +/- 1 db from 10Hz to 100Khz. The distortion is extremely low.
See
http://www.stevens-billington.co.uk/page102.htm
for a discussion of the transformer I use.
You can do a search on the web and audioasylum for
Thorsten Loesch, TVC, S&B, Sowter
See
http://www.referenceaudiomods.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=RAM&Category_Code=VOLUME
for the "Silver Rock" which was reviewed by absolute sound.
See www.jensentransformers.com for more on the benefits of low level signal transformers in audio.