Bob Carver 180 Mono-blocks perform superbly

Drac, well the difference is a lot like solid state and tube, so a comparison is not what I would call useful. When class D became recently popular there were some who wrote of hearing a tube like quality in the sound of their switching amp. I've had nine different switching amps in my system and none of them came close to sounding tube like.

My NuForce mono's began as the original Reference 9 SE and were upgraded to version 3. Generally speaking switching amplifiers are becoming more refined with the forward glassiness getting worked out. Channel Island, Nuforce, the big Rowlands, and the Hypex nCores to name a few.

I use switching amplifiers to power a pair of Avalon Acoustics Monitors in my studio. Their presentation that many find objectionable is exactly what I want from an amplifier in my studio environment.

I have used them in my main system but I prefer the relaxed presentation that only tubes provide for extended listening.

Switching amplifiers are simply a new amplifier option that many have found to meet their needs. The credibility and contempt by some in this hobby towards switching amplifiers is becoming more shortsighted. Design and technical improvements improve their sonic characteristics while maintaining their extraordinary efficiency and economical cost IMO.

I didn't know about the voltage differences in those tubes. Could that cause a problem? They were so inexpensive maybe I'll just forget about them.

Hi Vic, thanks for the description of sound of the NuForce.

I would contact Bob Carver, LLC and make sure those tubes won't cause a problem if you decide to directly plug them into your amp without rewiring.

Has anyone tried the cherry 180 amps with Thiel 3.6 speakers? Any opinions if the Thiels would be better driven with the Black Beauty amps? I am currently driving the Thiels with an older Bryston 4b (200w/ch into 8ohms) which has been a good combination.

According to Bob Carver, there should not be a significant difference in sound between the two amps except for the extra headroom of the BBs. I have heard that the KT120s on the BBs may sound a little sweeter up top than the stock KT88s in the Cherry 180. But you got so much choice in KT88s, you could probably get the sound you're looking for by tube rolling. You can't with the KT120, which is only made by one manufacturer. Based on what I've heard from the latest Bryston amps in different systems (but not in my own), I can almost guarantee you that Bob's amps will have better sound staging/imaging, more harmonically correct and less fatiguing sound than the Bryston. Bryston will probably have tighter bass. That's my edumacated guess based on my experience. I think Thiels relatively lean sound will benefit from a good tube amp.

Looking at the stereophile measurements of the 3.6 the impedance dips to 4 ohms at approximately 50Hz then continues down to 3 ohms for the remainder of the test and occasionally bottoming at 2.3 ohms.

While this might be a problem for many tube designs the Carver VTA's have a 2 ohm tap if needed. My Eidolons are a load that dips below 4 ohms and the 8 ohm tap sounds great.

I'd suggest calling Underwood HiFi, they may have experience with the 3.6.