Downunder: I would not have expected the Pass amp to be a good match with your speakers. Most Pass amps are a little "round" sounding in the bass, albeit in a pleasant manner. The problem is that, when you combine it with speakers that lack damping, suffer from ringing and are round sounding to begin with, you've got WAY too much of a good thing. The Vienna's definitely fall into that category, at least in my opinion.
As to the high feedback amps sounding "closed in", this is what i predicted that the JC-1 would sound like after learning that it used gobs of negative feedback. While i was initially eager to hear this amp, after finding out more about the technical aspects of the design, i knew that i would not like it sonically. Somewhere in the archives, you'll find those comments, along with what i posted above. That is, high negative feedback designs tend to sound less liquid and sterile. They measure good on the bench, but simply don't sound "magical" or "musical".
As such, i don't doubt your results at all. In fact, a couple of them simply confirm previous observations that i've already made, all without hearing the gear or combo of gear in question.
There is one thing i'd like to add though. That is, you guys really need to check into using low impedance speaker cabling ( 20 ohms at MAX ) with amps of this calibre. The benefits with amps of "marginal" build quality are noticeable, but when you've got a real "powerhouse" of an amp using good quality parts, the benefits become even more apparent. That last level of "musical accuracy" i.e. "detailed notes that float in the air, dripping liquidity and impact" become a reality. That's because the amp can finally "load up" into the speakers and the power transfer characteristics are improved. Better power transfer characteristics means increased control, reduced reflections and improved sonics.
In my Dad's system, i changed his preamp, power amp, DAC, modified his speakers, changed interconnects, etc... When i finally installed some low impedance speaker cabling, he told me that those speaker cables made more of a difference than all of the other changes combined. What he didn't seem to take into account was that the change in speaker cables simply allowed him to hear all the benefits of the upgrades that had already taken place, which his other speaker cables simply didn't let through. After all, the cables aren't doing anything magic, they are simply reducing losses in the system.
By minimizing the losses, you get to hear more of what the system is truly capable of. So long as you have a good system, you should like what you hear. If you don't have a good system, you'll get to hear just how bad certain aspects of the reproduction really are. Don't blame it on the low impedance speaker cable though, because it's not an active part of the reproductive chain. It's simply a conduit for the signal that already existed. Now you get to hear the system, warts and all. Sean
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