Autoformer versus Transformer Passives?

I think the isolation is the one theoretical advantage. There does seem to be less "stuff" in the autoformer which would seem to be a plus. I wonder if this bares out in listening impressions. All I know is the TAP-X sounds great, but I never was able to compare it head to head with a TVC. When I bought the TAP-X I was given the option to get it with the S&B tranformer or the Slagle autoformer and chose the latter simply on the grounds that in the passive world less should be better as long as you are addressing impedance matching effectively.

I had an S&B MKIII based passive made by K&K, but it was too long agon and the system context was different. I got the Bent based on user comments here and Teajay's review of the TAP. There seems to be the view that the Slagle autoformer sounds better the S&B transformer, but I've not seen much comment on Audiogon. If a preamp is suppose to be neutral and simply let the source to the amp with attenuation, it does seem passive setups with sufficient gain to drive the amp would function that way. I would like to see a shootout with something like the BENT-TAP-x versus some of the 10K and up active tube preamps. It does seem that a passive that can control the interconnect capacitance should be the ideal, with the amps adding whatever color or flavor the listener prefers.

Hi Anthony. I stand corrected. Have you heard any of the Slagle transformers stuff?

I asked John Chapman (BENT) about the ground-induced hum before I chose the autoformer over the transformer (he had a few S&B still available)and he said that in most cases that should not be a problem - I hear no hum so I imagine I'm safe on that ground. I'm not hearing any obvious HF nasties from my Accustic Arts DAC so hopefully this is a pretty good application for me. I would love to have A/Bd them but that was not possible.