what pre amp for ATC SCM 40v2 spkrs + 250.5 Pass Labs pwr amp

I've been really pleased with how well my VAC Ren MKV preamp pairs with my Pass XA30.8 amp, and hence picked Ralph's brain a bit about whether the preamp design lends itself towards good compatibility - including excellent and tight bass extension.  From the sounds of it, the VAC's transformer- coupled Class A1 balanced triode design is likely responsible for a large piece of the synergy.  I feel the combo is giving me a flavor of the best of SS/tube integration.

Thanks for your input @three_easy_payments, 
which model @tomic601 ? and what kind of system are you running?

my systems are visible on the virtual system page. The reference is an ARC REF5se preamp that while it does not meet the balanced standard that Ralph cites, make decent sound. It drives a 6 m length of Audioquest WEL cable effortlessly into Vandersteen M7 HPA amplifiers. I have used an inexpensive mogami set of XLR wire also with excellent sonic and low noise results.

I have spent more than a few hours listening to the Ayre KX-R preamp and it is an incredible bit of SS engineering. I have owned an Ayre power amp in the past and currently own and use in a recording studio an Ayre A2D converter - anything Ayre touch sounds good and is hyper well engineered.

just my two cents.

Ralph of course makes great gear also!

BTW the REF 3 is an excellent preamp

So then I kindly ask which SS pre-amps are you aware that meet these ideals that you mentioned earlier?

I don't keep track of them but as I mentioned earlier its usually pretty easy to tell if the preamp supports the standard. If it has RCAs in addition to XLRs as main outputs, and does not have either an output transformer or switch to go between the two outputs, then it does not support the standard. You can also ask the manufacturer of course; sometimes they will know but IME sometimes they won't; I've found many that don't seem to know that the standard exists.

But to be clear, stuff can sound just fine if it doesn't meet the standard- the ARC Ref3 is a good example as are the Pass Labs preamps. But you will find that you have to be more careful about the interconnect (which might cost as much as the preamp itself) and you could also run into ground loop issues. The insidious thing about a ground loop is they can cause degradation of the sound without making themselves known by obvious symptoms like a buzz. These are the things that balanced operation is meant to solve!


So if the preamp isn't going to support the standard, IMO/IME you are just as well off exploring single-ended preamps too.


Its the lack of support of the balanced line standard in high end audio that is why there is controversy in high end about which sounds better. All I can say to that is if you hear balanced line done right, there's no going back! But to do it really right, you have to support the standard.

While Ayre has always made excellent sounding products IMO, their preamps don't appear to support the standard- every one that I've seen has a single-ended output beside the balanced output.