Peeking inside a Carver Crimson 275 Tube Amplifier
Hello Frank, The curiosity centers on how is 75 watts of power derived from the lightweight diminutive transformers? Charles |
i am an owner of your carver 275 amp, actually like it alot, sounds very nice, wrote previously about my experience listening to it, which i enjoyed my speakers are fairly efficient and not a hard load (spendor sp100’s at 89 db.w.m and 8 ohms) so my listening to music does not tax the amp and ask it for big power, even if it makes 15-20 legit watts it could still make good music in my setup that said, i have also been kinda curious as to how the amp with its light weight (and thus small output trannies) would do a legit 75 wpc into real loads (or even an 8 ohm test load) as a point of direct comparison, my audio research reference 75 is also rated at 75 wpc, also runs 4x kt120 power tubes, and it weighs 49 lbs... open the top, the sizable output transformers are right there looking back at you
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Thank you for chiming in Frank. It looks like that ASR folks could have been more scientific in ensuring they were testing an actual amplifier built in California by Wyred4Sound. Now, this still leaves open the issue, what JJSS and Atmas-Phere are asking, how it is possible to get this output with so little weight? I really don’t want to ship mine to ASR to test. I also don’t want to open it up and take it apart to expose the transformers. I’m curious, but not that curious, as I know from working on this amp that you have to disassemble so much to get to trans covers off. |
@jbhiller, I enjoy this thread. I would use a hot glue approach ( I use clear door and window caulk ) to quiet down the mechanical properties of the cap and the mounting. These caulks have a sound, by brand, and of course, the amount used. Enjoy ! Always, MrD |
So our answer is.. “here’s referrals that say it sounds great” and “we measured 75 to 90..” That isn’t proof. Stats should be provable. If I’m a huge heel, if I just don’t get it, ok. I’m not the brightest bulb, but I’d like to be shown how 75 watts per channel are consistently put out by this amp. Then I’ll know I over reacted. I’d be the first one to say theres egg on my face. |
@funky54, Yes, I do think they need to just get to it and explain more about the transformers and testing. I have half a mind to open mine up to inspect the transformer situation. When will the sloppy guys at ASR be testing a legit one with a serial number? They seemed to indicate that was underway and then they went silent. |
My guess is it’s the same parts. Don’t care if he provided a cushion in slipping in the they were 35 wpc examples or not. I bet they are exactly the same parts. Same weight still..They had Mr. Carver there approving every step, they used the same schematic under Mr. Carvers’ supervision and both tested almost exactly the same.. in other words, they assembled things correctly. It’s a scapegoat replay saying the science was bad and they weren’t wirde4sound manufactured.. look at the back peddling already.. advertised as 75 wpc not its 75w for one channel but only measured without much bass… WHAT? I really don’t need any more reply or lies. The amp is a fraud. Maybe its an ok sounding 17 wpc amp. But it’s missing 4.5 X the power. Like that’s ok? It’s like saying “I brought $1000 of the $5000 I owe you, but you’re cool with that right?” |
Well, Curiosity and my love of drilling down to get to an answer got the best of me. I took the PCB off its mounts and got to the output transformer. I didn't not get to both OPTs, as this would be more work and I think we can assume both OPTs are the same. I'm sorry that I didn't get to the power transformer (middle can); this would require me to detach numerous hookup wires and for me it would be an hour's work to properly desolder and reinstall it all. Oh my! I'm an idiot when it comes to posting media via Audiogon's new forum features. So, you'll have to look at the photographs here: They are in my virtual system. The Crimson 275 I bought (from Music Direct) uses 15w Edcor OPTs. UGH!!!! Frank Malitz, can you please explain this? While I love the sound of this amp, this hurts my ability to pair it with less efficient speakers, hurts resale substantially, and isn't cool---UNLESS, Frank, you can get Bob Carver to issue a statement explaining how this amp can make specified output. Finally, if you're reading this please note: Before folks throw Bob under the bus, remember the following. Bob designed this amp with another esteemed audio sage. He reportedly sold the amp and the rights to sell it to Frank Malitz and/or Carver Corporation--and Bob is not an owner of the company. Frank told me he's a designer only. When Frank says Bob was angry/sad/emotional about the issues being debated on the forums concerning this amp, that may be true. And Bob may have never intended to post faulty specs, etc. Frank Malitz/Carver Corporation, can you have your partners at Wyred4Sound test the output and reconcile it with your specifications for the product? I'm more sad than angry about this. It's still a hopping little amp, but now I know it won't work in my big room (16 x 23 x 10 tall) with inefficient speakers. Currently I use 102dB efficient in this space, so as I said before I had not way of knowing if this thing could power such speakers. This is a very sad day for me. Great amp. More than likely false advertising. Should I ask Music Direct for a refund? |
Also, now that I feel it’s appropriate to pile on with questions given the evidence...
Even though Frank says these amps are always sold out, they were always available at Music Direct. Just recently, Music Direct’s website started saying the product is "no longer available" --not backordered or special order or drop ships from manufacturer. Did Carver Corporation take this amp off the market in response to criticism?
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😥 Thanks for that, though. Now we might expect some sort of tug of war over what constitutes acceptable bandwidth at power, THD limits, and measuring setups - and how this should all filter down to single power #. It’s perhaps interesting to look back at Heathkit W5 manual from 1959 and all the wonderful measurement curves provided right in the manual (the bandwidth looks very good for a 25 Watt rated tube amp):
To be fair my VAC amps don’t exactly measure stellar either - and I enjoy them regardless. |
Thanks @tomic601 @mulveling , you make good points. It's still a fine little amp. One of the biggest reasons I purchased it was its ability to drive all sorts of speakers. I seriously question it can drive a 4 ohm load at 75 watts even at peak power. But, I'll leave that for the testing experts and true electrical engineers. |
I don't know anything about circuits or amplifier design....this is from the Carver website...take a look at pages 11-13 and their description. What I can say is that I heard the 275 at the Florida Audio Expo...one year playing the KEF Blade 2's and one year playing the Amazing Line Source...and those two combos sounded pretty darn good. |
@snapsc
Oh my - it spec’d the rated power at both channels driven, full musical bandwidth, and 1% THD. That doesn’t leave much room for interpretation, and it’s going to be one hell of a tall order for those little OPT’s 😬 |
I posted this on the Klipsch forum and I think its holds true here as well: At the end of the day, I have yet to see anyone on any forum say the amp does not sound fantastic. While it's tough to see what may have happened, isn't that why we do what we do in our spare time? Reach for fantastic sound? Bob should be congratulated on that, but I suspect someone will have to pay the piper for how it was marketed. |
I’m very sorry @jbhiller. I feel for you. You were promised with published specs by a assumed reliable builder with a famed reputation. I believed in him too. You mentioned “The Big Room”.. I came very very close to buying two to vertically bi-amp my Alon IV speakers. 3 ohm, 86db. Can you imagine if I had bought them? I’m sure the truth will keep surfacing. You won’t be alone. |
funky54: exactly. Several of our forum mates now find themselves in a very uncomfortable position & empathy for them is the order of the day.
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Two separate issues here. 1, Sound quality (Which many have confirmed). May only be capable of good sound quality into high sensitivity speakers with benign impedance load characteristics. 2, Truthful and accurate specification information (Which is seriously being scrutinize). People shouldn’t be led to believe that they’re purchasing a legitimate 75 watt per channel amplifier if they are not (And possibly getting power far below the specified 75 watts). This is wrong, plain and simple. Frank needs to provide a more thorough explanation with actual verified measurements. Charles |
If you added $3-400 kin parts ,especially coupling capacitors , Vishay naked resistors , better wiring and Thst cheap Chinese crap has no business in a amp of this cost , rule of thumb as a ex Audii dealer only 25% of the cost actually goes into the build including all components, case , and packaging meaning $2500 including even tubes on a $10 k unit , that leaves very little for high quality transformer and chokes .too much greed for a lousy $300 in parts actually $200 or less dealer cost you could have had at least half way decent coupling caps like Mundorf Evo ,or clarity CSA ,that's just taking a piss in my opinion. |
I posted the measurements firs to HiFi Haven, then to ASR, and I am happy to answer any questions about how I performed the measurements. It was pointed out to me by a Carver dealer that the units I have are not serialized, so I went ahead and bought a new amp which should arrive any day, and I am taking that amp (unopened) to a neutral 3rd party to be measured independently. I would also note that I published a subsequent review of the ZOTL-10 to HiFi Haven as well, just as another reference point. Mostly I am here to thank JBHiller for taking the time to pull one of the cans off his output transformers. |
So many great comments here Team. Thank you. I’m so ambivalent. Before we/I move to my/our reptilian brains and go scorched earth.... If you will allow me... Bob Carver grew up obsessed with hifi. He was a tinkerer-turned-PhD in physics. As a boy, he reportedly showed up at McIntosh diagnostic events. These were marketing and goodwill events where McIntosh would bring its big boy engineers and semi-founders out to cities across the country inviting America to bring in their hifi kit that had ground loops, crackling pots/switches, and so on. McIntosh would help diagnose the visitor’s product. [Don’t you wish AXPONA would have this?] I’ve heard they certainly would, without putting down other makers, explain how things could be designed better in the customer’s unit in order to avoid the customer’s issue altogether. Kind of cool. They would also service Mac stuff at these events. They traveled the US. Very different than our world today where brick and mortar is dead, and I just buy crap because I like to play with it and it gives me an excuse to hear more beautiful music. At any rate, Bob Carver would (again reportedly) show up to these events on occasion and bring things in like the others. Yet, Bob, was so out there, that he was brining in his OWN IDEAS as a teenager. He once (again reportedly by my research) brought a Maxwell House coffee can into the McIntosh weekend diagnostic event. He told them he was working out a circuit and was close to Xanadu--I’m editorializing now. :). They refused to plug it in out of concern for safety and electrical hazard. That said, they were impressed with the circuit (not the coffee can). Bob is a human. A genius in my mind. I’m not sure how good he was in business decisions or business acumen. But, I don’t know what the standard is to define that. I think Bob sat down with that European amp designer and felt romantic about the days of Marantz, HK, Scott, even HeathKit, and many others. Bob knew many of those in audio history. I think he created an amazing little hot rod of a product. If I had to guess, I’d bet he thought we have come so far and sometimes we get lost in the simplicity of things that made good sound. The marketplace is better for this Crimson 275 amplifier, regardless of whether it puts out wattage of 17, 35, or 75 (or even 90 as I think Frank M. has claimed at times). It’s a cracking little device. Look, I sold a top of the line Primaluna because I preferred this little dude. He struck a spot that my 300B couldn’t reach. This thing works. Now, don’t get me wrong. This is not a perfect piece of gear or "the best"--whatever that is. [Do you ever believe you’ve had a "best" anything? Best pizza, lover, beer, bourbon, day off, etc...]. It’s just a little amp that likes to boogie. Does your/my other amp like to boogie? I’ve had both the boogiers and those that won’t. Enough said. Watch, this amp will be like that girlfriend or opportunity that I let escape due to forced apathy. 😏 |
@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. :)
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@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. |
@funky54 , You are 100% correct. There's a big wall of ego out there that should not be excused. I just wanted to make the point that I want to hold off on personally attacking or criticizing Bob Carver given its undisputed he does not have any control or input into the company. Certainly we can say he knew or should have known. But he's not the company or even apart of it.
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@jbhiller from reading your posts in this thread I have a strong impression that you look for the good in others and are peaceable, and reasonable. I admire that. Don’t change. |
@funky54 ...Thank you Sir/Madame! I'd enjoy having a beer or coffee with you. |
By all accounts the Carver Crimson 275 is a very good sounding amplifier. They should have just marketed as a low-moderate power tube amplifier with high quality sound that would a terrific match with appropriate easy load impedance speakers. What’s wrong with that tactic ? There’s certainly a market niche for this type of amplifier. Put emphasis on watt quality as opposed to watt quantity. It seems so silly and unethical to claim a power rating it apparently is not simply capable of achieving. An otherwise good sounding amplifier that unfortunately becomes fodder for the measurement crowd to pick apart and ridicule. A very avoidable situation. Charles |
+1 @charles1dad |
@charles1dad --You've nailed it again. There would be nothing wrong with saying, Carver Corporation challenges you to see how few quality watts will make your speakers sing your favorite music. Less is more! In fact, Carver Corporation recommends you try the Crimson 275 first (over the mono blocks of higher power), as many customers find that's all they need. And then give the testimonials about KEF Blades, etc. sounding wonderful. |
quick report i just had my amp in for a check (some tube noise and transformer hum) at wyred 4 sound - w4s is the exclusive contract manufacturer for these crimson amps had a friendly chat with their senior tech who worked on my amp - i know the w4s guys reasonably well, like them, have several pieces of their gear (digital, power supply, class d amps), w4s is a good company, well designed well built, good sounding high value gear, good reputation, and straight shooters in my book i was told that based on their bench experience, the crimson amp can make 75w driving one channel... (didn’t ask for frequency range spec, sorry), can’t in both channels though (’more like 60 thru both channels’), but this isn’t due to the output transformers as limiting factor, but rather, the power transformer, which can’t quite deliver the juice for 75 wpc asked how such a small light tube amp makes that kind of power, was told that the reason is the kt120’s are pretty strong, plus ’the neat feedback circuit employed from the output, holds the distortion in check, other guys don’t do this, we were kinda surprised it can do that through those small output transformers...’ so that is what i learned... perhaps frank m, after consulting with bob carver himself will chime in again, say more for me, i own the amp, bought it used on a lark to try, like it quite alot, drives my spendors and harbeths very nicely, sounds great, runs pretty cool, is small, light, easy to move around... so i’ll be keeping it in my stable of amps - yes, the power output spec may well be overstated by the seller ... oh well, i’ve done a lot worse :) |
Nobody so far thats independent of Carver affiliation, is getting even 60 watts per channel. Yes they should have used a bigger power supply and maybe gotten a realistic 20 wpc. That would have been possibly a decent marketable product. But hey, if you only run one channel without half the frequencies that matter, it could be a wonderful center channel home theater amp. For potential customers that use efficient speakers I’m sure it does sound great. Lots have attested to that. But what about the other half who have in-efficient speakers who wanted to pair them with a well selected amp? Carver knew they’d lose half the potential buyers, so they lied. Now half the people who bought them are not seeing the full potential of their sound.. I listen on average around 76-82 db in a 26 x 40-ish room with 13’ ceilings. Even at those db’s, I can easily hear the difference in a 100 watt per channel from a 200 watt per channel. I can hear the difference between one power supply and two power supplies with the same wattage. The Carvers that I almost bought, would have been a disaster. |
Honestly if I were an owner right now, a solid 60 Watts x2 would be OK with me, even at THD a point or 2 above 1%. I’d certainly be disappointed at being sold misleading/erroneous specifications, but that would be "close enough" - 60 versus 75 is still usefully powerful. 17 - 20 is another story. Hopefully we'll get more clarity soon. I know W4S cited the PT, but I’ll be really surprised if those OPT’s push out 60 Watts x2 as recognizable music. Anyways, my audio tech & now dealer has been Gordon Waters here in Marietta GA for many years. He’s designed speakers and restored countless vintage tube amps (including a couple of mine). I trust him implicitly. On Audiokarma he posted the following interesting analysis about the Carver 275 schematic (which to Carver’s credit was included in the manual) - no comment on the transformers, just the circuit: I was just having a conversation with some really astute techs about the Carver 275 amp, regarding a feature I just noticed, in the schematic: |
After all this dust settles, let's not forget what the late great Ken Ishiwata said, "Unfortunately, specifications don’t tell you about sound quality. That’s not just for DACs, it’s for everything. Those specifications are all based on static measurements, but music is dynamic and there are many other parameters that influence performance."
I'll take Mr. Ishiwata's view over egghead testing alone. This guy had a dedicated listening space where he tested and tweaked products on sound quality--albeit he did care significantly about specs too. |
Absolutely, I agree listening results come first. This is specifically about whether Carver needs to down-rate its amplifiers, not whether the amp deserves to exist. Likewise, it raises the question: do we have a problem in the high-end 2 channel amp industry right now? Do we need to look at other companies and how they’re rating amps? Maybe we’ve been too comfortable since the HT receiver "peak power" rating debacle in the 90s / 2000s - back then it was easy to say "haha, HT guys - not my Krell!". What about now? I hate taking sides with the ASR guys because they’re measurement zealots and (mostly) outright anti-audiophile. The overall theme of that forum is listening tests come DEAD last - which to me, means their real hobby is measurements - not music. |
@mulveling , You make great points. I agree wholeheartedly. I didn't mean to suggest that listening excuses any of this! You also are on to something, I think, about whether there might be a problem in the market right now. I had an NAD M22 amp that Stereophile gave a Class A, glowing rec to a few years back. It was a wonderful product and I'd recommend it. That aside, even with its hundreds upon hundred of crystal clear watts (it tested ridiculously well), it couldn't beat out a nice Creek Evo Integrated of lesser power, driving all sorts of loudspeakers. Buying on stats alone wouldn't tell me that. Why ASR's zealot faction (not all of them) refuses to listen at all is beyond me. I've got a 9w tiny tube guitar amp that will but a big grin on a guitarist's face. It hums, has limited power, and is soooo far from state of the art. I have guys begging me for it. If you tested it you might be scared to even turn it on. Tests have a difficult time testing and relaying information about tone, timbre, etc. Those things matter a bunch not just to how we reproduce music but how we make it in the first place.
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Totally agree! Haha that reminds me several years ago - I had 400 Watts/ch Parasound JC1 monoblocks, then VAC Auricle 80 Watt KT88 monoblocks - and picked up a pair of 50 year-old 20 Watt Heathkit W4 mono amps (restored buy Gordon) on a whim. The JC1’s were GREAT amps but I’m almost embarrassed to admit how much I enjoyed those little Heathkits - they were just so sweet sounding and enjoyable. NOS Tung-Sol 5881 tubes. Soon I learned the limits of that 20 Watts on my (then) 90 dB speakers (Tannoy Dimension TD10), but it really impressed me how amazing even simple tube amps can be. |
A couple of other forums that are discussing this subject have noticed this thread. Jbhiller’s shared experience about his transformer is now out there to add to this.
It’s funny how all the threads go in a circle about “We’ll,…. It sounds good so it’s a great amp… measurements only tell part of the story” All true from my perspective. But that candy coats the turd… we were lied to. It was intentional. The guys with the 97db efficient horns can feel at ease and keep mentioning it’s a nice amp.. what about the rest of us? I’m 3 ohm at 86 db in a 24x40ish 13’ ceiling room.. think it would sound good at 86 db’s for me? It’s just not right. It really burns me up. |
That sounds like a tall order from any amplifier that room is huge-- Carver has a free 30 day in home trial period which I think is fair. If the amp doesn't meet your expectations simply return it for a full refund. Now that does not justify purposely mis-leading specs it looks like the OP (Paul) over at ASR finally received his factory unit so new test results should be out this weekend, hopefully they're a bit better than what we've seen so far.
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I have to agree with funky54 now. I would be surprised if the amp tested substantially better than ASRs previous measurements on wattage. I'll less surprised if distortion measures a touch better. I've built and tweak stuff--sometimes to excellent ends, and sometimes not so much. I have a firsthand experience with price point construction decisions--granted I'm not an expert and my experience is limited in scope. Most all of my thoughts way above (before this testing/fraud issue rose) remain true. One thought was, Why shoehorn this product into the $2700 price point? I'm not saying overbuild it or price folks out of it, but wouldn't an extra $1,000-$1,500 charge allow the manufacture to (a) use legitimate capacitors where they matter instead of $1 junk; (b) beef up the transformers.
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