Steve,
Years ago I decided that a major weak point in any preamp was the level control.
That's when I figured that something of moderate cost would be best, but with the electrical environment optimised with low source impedance and high target impedance.
That was the genesis of the GK1 back in 2001; the other benefit of this approach was lower noise from the gain block since it's always working at full line level.
I discovered that SFernice made ceramic pots which sounded very good because the ceramic substrate was much harder and the multiple contacts thereby eliminated over the conventional carbon type. But SFernice (a small company established in Nice, the South of France) was absorbed by Vishay, the Philly based US company which also bought Beyschlag, Roederstein, and a host of other passive component manufacturers in the last 15 years, and the ceramic pots are no more.
Dammit.
That's when I went for the Panasonic EUWM, only available in motorised form and used in my Swift. These are very good.
I have been experimenting with shunt wire pots. They seem very good too, and this configuration can tolerate carbon pots without reduction in sound quality.
The switched attenuators are, some say, the ultimate, but they are a mechanically complex, miniaturised component, with so many moving parts, wear and friction is an issue and they do wear out. AND they are VERY expensive. The cheap Asian versions from Taiwan (MY3C.com) are really only durable for a few short years, as you would expect, but they look very nice.
Transformer attenuation to me is ridiculously expensive, and I cannot see the advantage, and I suspect that RF pickup could be an issue. Very bulky.
Cheers,
Hugh
