Is an autoformer (AVC) always superior to pots and resistors ?

This is an argument some of my friends made to me. AVC is always the best volume control, better than anything else such as rk50 or resistor based volume controls. Have you found this to be the case?

I am also curious why AVC is not implemented more often in high end audio preamps / integrated amps.



Great question.  I have been looking at the icOn 4PRO passive preamplifier (that uses Slagle autoformers) as a possibility to provide remote volume control and a display in front of my solid state buffer.  I am currently using a Hattor passive preamp in that role but I have been curious about the icOn and how the sound of an autoformer based volume control would compare to what I hear from the AMRG resistors in the Hattor.

I had an Acoustic Imagery Jay-Sho (autoformer) preamp a few years ago but found that using it alone (without a buffer) left me wishing for more weight behind the dynamics.  To me, it sounded a little too smooth compared to what I was used to with resistor based units.  However, using autoformers to control volume in front of an active buffer or low-gain active stage might be a design approach that would provide the best of both worlds.  I would like to try the Jay-Sho again, or the icOn, in front of my SMc buffer or Hattor's Tube Active Stage.

My experience has been to get one of Dave Slagle’s autoformers and be done with typical resistor type volume control. 

I've tried an AVC incorporating Slagle's parts. It sounded dead quiet but my system needs a bit more boost and I like the coloration added by my 6SN7 tube.


I prefer optical comparator, crossing at zero (silent)

The PS Audio gain cell design is superior also.

I can only say I love my Coincident Statement MkII pre with dual transformer volume control, superior to any pot or resistor based volume pre I've owned. Absolutely most stable imaging imaginable, no tracking issues whatsoever.