Passive/active preamp (transformers, resitors)

[bbest]

Hello!

I have balanced source on ES9018 and balanced beta22. Besides this intend to assemble stax balanced amplifier. Wanted to use some high quality volume control for all amplifiers.
It is dilemma what is best choice: TVC transformers or resistive preamp. Transformers could be choosen between Sowter 9335, S&B, Silk STA-522A and others.
For resistive preamp must be use buffer. I choose amb alpha24 with opams OPA1612, OPA1632, fully-differential outputs. Also good choice is Khozmo preamps with z-foil resistor. The best performance gives ladder or buffer stepped attenuators. Quality of resistors does matter. Best choice is z-foil.
The main question: what is bestes - transformers or resistive preamp? Needed ultimate sound quality after simple volume control.
What your opinion?

 

[abraxalito]

Transformers, in my experience, make the best volume controls. If you wish to use a buffer, don't make it an opamp, go for something classA (which normally means discretes).

 

[bbest]

abraxalito, thanks for opinion. How you think, what transformers are best (cost not more than 1000$ for pair)?
Opamps are really not good choice. The same question, what better to choose for classA(discretes), may be something on ebay?

 

[abraxalito]

For TVC you could wind one yourself on a ferrite core. I bought myself some suitable cores a while back - the bobbins had dozens of pins to bring out lots of tap points from the windings. Since acquiring them though I've been too lazy to get on and build them into TVCs.

I don't have any experience of buying audio kit on eBay so I'll pass on your second question.

 

[bbest]

As for transformers vs resistors: transformers best on low level attenuation. But on high level, near proportion 1:1, resitors could make competition with transfomers.

 

[Ken Newton]

abraxalito, thanks for opinion. How you think, what transformers are best (cost not more than 1000$ for pair)?

Here's a well regarded TVC available for as low as $200 for a stereo pair - see them near the bottom of the linked page. That said, I have no personal experience with them.

intact audio