This is from Arthur Salvatore's Website an excellent reference source from a passionate audiophile http://www.high-endaudio.com/RC-Step-ups.html
Hope it is of some use to you
Groovey
CLASS C
MITCHELL COTTER/VERION TRANSFORMERS
These models were the finest moving-coil transformers ever made at one time, and the best I heard, overall, before the Expressive Technology came into existence. They had excellent sound; natural, detailed and dynamic, though with both of the frequency extremes rolled off a little.
It came stock with its own (4') output cables already attached, which was a strong advantage, but now it is a decided disadvantage. The cable's excessive length and (now) mediocre quality both compromise the Cotter's inherent performance. A competent technician must be found to remove and replace them with good quality RCA females, which would then allow the use of any superior phono cable.
There are different models of this transformer that have different input impedances. The model with the lowest input impedance (2L) is usually the most desirable version with current cartridges.
The Verion was the exact same transformer as the Cotter, before the name changed due to legal reasons. However, unlike the Cotter, no version of the Verion was ever offered with the lowest (L) input impedance, as far as I know.
FURTHER: The original Bryston transformer (black) was the exact same model as the Cotter, with just a different name and color. It was even built by Cotter.
However, the current Bryston transformer, with the model name TF-1, is a different design. Chris Russell, the CEO of Bryston, claims this model "has a wider bandwidth and 40% of the measured distortion of the Cotter/Verion unit." I am sad to admit that I haven't heard this unit, despite the fact that it is made in Canada.
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