Peeking inside a Carver Crimson 275 Tube Amplifier


So, I just had to pop the hood on the Carver Crimson 275 tube amplifier. I was so curious as to how this little guy weighs so little and sounds so lovely.

  • The layout is simple and clean looking. Unlike the larger monoblocks (that cost $10k), this model uses a PCB.
  • The DC restorer circuit is nicely off to one side and out of the way. It doesn’t look all that complicated but I’m no electrical engineer. Why don’t more designers use this feature? It allows the power tubes to idle around 9.75w. Amazingly efficient.
  • The amp has very good planned out ventilation and spacing. No parts are on top of each other.
  • Most of the parts quality is good. There’s a host of Dale resistors, what look like Takmans, nice RCA jacks, heavy teflon hookup wire, and so on.
  • Some of the parts quality is questionable. There’s some cheap Suntan (Hong Kong mfr.) film caps coupled to the power tubes and some no name caps linked to the gain signal tubes. I was not happy to see those, but I very much understand building stuff to a price point.
Overall, this is a very tidy build and construction by the Wyred4Sound plant in California is A grade. I’m wondering a few things.

Does the sound quality of this amp bear a relationship to the fact that there’s not too much going on in the unit? There are very few caps--from what this humble hobbyist can tell--in the signal chain. And, none of these caps are even what many would consider decent quality--i.e. they aren’t WIMA level, just generic. This amplifier beat out a PrimaLuna Dialogue HP (in my room/to my ears...much love for what PrimaLuna does). When I explored the innards of the PrimaLuna, it was cramped, busy and had so much going on--a way more complicated design.

Is it possible that Bob Carver, who many regard as a wily electronics expert, is able to truly tweak the sound by adding a resistor here or there, etc.? Surely all designers are doing this, but is he just really adroit at this? I wonder this because while some parts quality is very good to excellent, I was shocked to see the Suntan caps. They might be cheaper than some of the Dale resistors in the unit. I should note that Carver reportedly designed this amp and others similar with Tim de Paravicini--no slouch indeed!

I have described the sound of this amp as delicious. It’s that musical and good. But, as our esteemed member jjss [ @jjss ] pointed out in his review, he wondered if the sound quality could be improved further still. He detected a tiny amount of sheen here and there [I cannot recall his exact words.] even though he loved it like I do.

I may extract the two .22uF caps that look to be dealing with signal related to the 12at7 gain tubes and do a quick listening test.
128x128jbhiller
Carver knows what parts really make a difference…..and which ones DONT. 
Go ahead and chase your tail. Knock yourself out! Placebos and sugar pills will make it sound “sublime!”
I used to own the Black Beauty, It ran very difficult  speakers and can handle difficult loads, Unfortunately Bob carver setup Distributors globally and got everyone to buy and market the amps for some time and then dropped all the distributors within an instant. Nice Amps but the people running the company have no idea.

If you need allot of power these make sense.
Guys it’s not the caps that are the biggie. Resistors are where GREAT quality comes from. Good caps Russian PIOs Mundorf MCap and Vishay copper resistors.. AND yes WiMa would have been a heck of a better build...

But the guy that voiced that amp is NO DUMMY.. He can really come up with GREAT sound on the cheap.. Carver was a transformer genius.

He use to teach classes, 45-50 years ago.. Worked with a few apprenticeship programs to get your requirements..

I did a 3 day class with him. Had a pair of forearms like an APE, from hand winding transformers.. Great guy back then.. SMART very different approach to sound too.. I was a serious Mac guy.. Do you see a problem.. He sure did.. LOL

Really though, you should see Carvers Point to Point.. pure art.. The 275 reflects his voicing BUT really NOT his ability to lay out a beautiful valve amp.. Two different things..  Good units.. the 275.. Tinkers delight for the price.. COOL running, lighter.. I like um..
wima properly formed and or bypassed is a great cap….
take the two BIG hints…..
Hello jbhiller!  Bob Carver is a superb designer. He sells his company every ten years or so and starts another one to keep from getting bored. The man is an audio genius. If you replace those "iffy" capacitors, don't use anything less than Mundorfs with the appropriate rating. Since there are only two, go for the fanciest ones. Be sure they will fit. The Duelands for that rating are HUGE. Enjoy!