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

@paulbottlehead ,  You open the stuff up way more frequently than I.  So, THANK YOU.  It was a bit of a pain to do this.  I had to, incidentally, re-solder the wires linking the meter to the board.  That involved careful desoldering and patience to be clean and precise in tight spaces.  Then my OCD kicks in and I have to check everything out in the compartment.  Does this weld look good?  This could be cleaner right? 

Thank you for chiming in!  I hope the weather subsides and you get your Crimson 275 from the dealer to test. 

Don't forget!!!!  AFTER YOU TEST YOU MUST SIT AND LISTEN!

Sometimes stuff that doesn't test so hot sounds great.  I have a $300 guitar amp like that.  It'll smoke big boys with its swagger in tone.  

Keep us posted too Sir!! We welcome you here in the land of subjective, compulsive, and irrational audiophiles. :)

 

@jbhiller those are nice respectful words… but it’s not a two-way street. One man buys a top of the line loaded diesel powered $75,000 pick up truck because he really likes the looks of it and just needs to cruise to work and back and around town. To him that pick up truck checked all the boxes and he thinks it’s amazing.

another man buys the exact same model because he needs to move bulldozers across the country.

Now imagine that the manufacturer didn’t put a 1000 ftlbs of torque (edited for one’s happiness) diesel motor in the truck. No, he put a 200 ft lbs of toque four-cylinder motor in the truck.

Now I ask you, it may be a wonderfully made four-cylinder motor. It may cruise around town for the first owner just fine. But do you think anyone’s going to be impressed or praise the manufacturer or respect them as a company because for one client it could cruise around town smoothly? For the second owner it couldn’t even toe a lawn mower not to mention bulldozers? They didn’t better the market with an amazing truck. They pulled a fast one and out of greed, laughed in both owners faces. Fool me once… is the old saying.

I’ll also remind… to hide, cover over, our reply that we received was… we’ll the carver fest kits were 35 wpc versions? (Same parts and they know it) and, we’ll… that’s with one channel measured with most of the bass pulled out to meet 75 watts… hard to respect or admire a cover up. Respect is a 2-way street. Do they respect us? They think that we’ll never know the difference, we’re idiots. We’ll believe 35 watt kits and one channel measured… or they think, we won’t understand specs, just read the referrals.. that’s what matters.. meanwhile the bulldozer can’t go anywhere. The work can’t get done.

I'm just trying to imagine a pickup truck that has anywhere near 1000 horsepower.

Not the best analogy.

Ah! Thank you.

You have freed my imagination to once again wander the empty halls of my head.