@jbhiller , That's a very good SE option list, here is the W4S contact email; support@wyred4sound.com
Give it a try?
Give it a try?
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.
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.
- 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.
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.
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- 234 posts total
@jbhiller, I have to tell you that those proposed amplifier modifications/upgrades for a final product cost of 4500-5000.00 USD seems very reasonable and doable. This would be a high quality very good sounding tube amplifier with a price that is assessable for a fair number of people. @corelli +1 regarding the demeanor of this thread . Reminiscent of how this forum was when I joined about 12 years ago. Charles |
@corelli, Sure, I'll give it a try--remember, these are my ears, my room and my gear. First off, I love what PrimaLuna does and stands for. I had a wonderful experience with them. I love what Kevin Deal does. He's a good guy with tons of knowledge. I think he's a tremendously positive businessman and a lover of all things hifi. The PrimaLuna is a fantastic build and sounding amp. The remotes are to die for. (Speaking of which, my remote had issues and they ultimately gave me a new one ($250) for free even though I was well past warranty expiration. I really loved the PL when it powered more modern loudspeaker designs--KEF LS50s, PSB Imagine T3s and T2s, Dynaudio, Golden Ear, hmmm...what else, oh, B&W. I'm sure over the years I heard others. Never a bad match with any stuff I had or heard it with. Disclaimer--I have not heard the PL EVO range. The PL I had was the Dialogue HP. That thing could seemingly power anything! It was built like a tank. The construction is super. It is really gold standard on point-to-point, layout, clean build, etc. I wouldn't want to service one or go back in one, as there is little room in the bigger models' chassis. I felt like a surgeon in there. Pros to PL
Cons
In my system, the PL sounded BIG (I have efficient speakers), bold, pleasant, and generally musical. Imaging was good. Bass was large. However, compared to the 275, the sound was thicker, denser. The 275 is sweeter, substantially more holographic, clearer, more delineated without being hyper detailed or analytical. I've never really understood how to use the PRAT description but I suppose it would fit. The 275 boogies. It swings. It's sweeter, creamier, but has more air too. I just go for what I hear and what wins in my personal shootouts. Maybe this will help--- I built a highly upgraded Elekit 300B amp (see Herb Reichert's reviews on it--it's pretty amazing). When I had the PL, I would go back and forth between the PL and the 300B. The 300B gave me water like clarity and rich detail. But, as Ralph of Atmasphere correctly taught me on these forums, the 300B has little distortion at very very low wattage--once you start getting up to like 30% of its power, it starts distorting substantial. The PL gave me balls and bombast--also a killer remote, tons of inputs, and tube rolling fun. When I got the 275, I ultimately stopped using the PL. And, here's what was surprising to me--I used the 300 B a bit less. Why? I asked. I think the answer is the 275 has a healthy dose of clarity, sweetness and space with holographic images. Note--I'm not saying the 275 is better than the 300B, but I use the 275 way more. When I started messing around with the PL, I was never really able to tweak it to make it sound like what I thought was missing or what I was after. Again it was a great sounding amp. With the 275, I thought it fit my taste better for long term. So I sold the PL. Someone out there has a PL with VCap CuTFs on the two gain tubes. :) I think the 275 is about 75-80% stock of where the amp could be, but I'd defer to Mr. Carver for sure. Our esteemed member JJSS bought one and tried it about the time I got mine. He has some killer gear, and great ears/experience. He liked it much but felt there was just a bit of sheen or haze on top--I think he said he might be nit picking though. I agreed. So I cracked it open. My jaw hit the ground when I saw these. https://www.suntan.com.hk/Plastic-Film-Capacitors/TS02.html. Not because I think you have to have boutique or hi end parts to sound good, but because the amp sounded pretty darn great with inexpensive caps that I think are below good quality WIMA, AMtrans, and so on. So I though, King Bob Carver's circuit and know how was squeezing everything out of those mediocre-at-best caps. How would it sound with legitimate caps? By the way, the physical size of the original caps in the 275 is almost laughable. The .22uFs on the signal/phase section are no bigger than my pinky finger nail--actually smaller. I'm inclined to tweak via a cap, resistor, or tube before going after a $1K power cord or interconnects--just me. I have decent cables, but none costs more than $200, maybe $300. Finally, keep in mind that I'm running Klipsch Cornwall IVs. I just don't know how this amp would sound with modern, less efficient designs. I would expect it would sound great. Who knows!? It's got balls. Also, Bob is a genius. The PL would heat my room. The 275 weighs 18lbs or so, I can lift it with one hand, and it never puts out noticeable heat. I think Mr. Carver admitted he lifted and tweaked the DC restorer circuit from 1950s television design. It idles those big KT120s at 9 watts or something insane. It's not a gimmick. It works, saves energy, less heat, and your tubes last longer. Oh, one more thing-- the user gets to set the bias (sooooo easy--do not be bashful) on the 275. I run mine around 70, which produces a big soundstage and images. |
Thanks guys! Yes, I don't get the negativity out there. When I'm on guitar forums, it's soooo rare to hear someone tell another their view is stupid or they don't know what they're doing, etc. In guitar world, for instance, techs set the gold standard on how strings should be wound and say do not wind them more than 2-3 turns max (or something)--YET they admit guys like BBKing wound the living crap out of his strings and no one ever said, Hey BB sounds like his intonation is off and he's constantly re-tuning. There is more than one way to skin a cat. :) |
Check out the pic in my virtual system (last one) of the original caps. You'll see I used a Phillips screw driver head from my impact driver to show the scale. It's shocking. https://systems.audiogon.com/systems/9364 |
- 234 posts total