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

Reality slaps some people harder than others. If you mistake that for killing puppies, you are part of the problem.

@ozzy62 thanks man, you’re a gentle sweetheart of a guy. Maybe there are some puppies you can kill or someone’s grandma you can push down some stairs?

The ASR test and review really nails it! This is a broken amp that can't make its specified power and distorts terribly at 35hz and below! What was Bob Carver thinking when he chose those small 15 watt Edcor trannies?

My custom-built Will Vincent SET 45 amp has way bigger Edcor trannies than in the Crimson! Without the proper size iron the Crimson is dead in the water! No swapping caps or resistors can redeem it!

jbhiller, what you could do is run clip leads from each negative speaker terminal to the corresponding outer shells of the inout jacks, thereby bypassing this feature, and see if it sounds different.

Post removed 

@funky54 

No 75 wpc tube amp is going to deliver into a 3 ohm load and 86 db sensitivity. Especially in a room like you described. It just shows how foolish you are to consider it.

Thank you @grovergardner !   Great intel!  I'm wondering if I could make a switch to adjust the damping factor as a project.  Hmmm...

jbhiller, don't swap out those resistors.  They provide "current feedback" from the output transformer, you won't gain anything by changing them.  To the contrary, some feel the amp might be improved by bypassing them.  Many amps in the 50's offered a similar arrangement, except with a variable resistor, to adjust the "damping factor," a way to "loosen" the amp's grip a bit to accomodate speakers with poorer bass response.

I wouldn't think so, but Bob has a PhD in physics.  His response suggests it will.  I'd bet it won't, but who am I? 

It will be sad if he goes into retirement making this representation--that it, it will exceed 75 w per channel, both channels driven at 8 ohms.

The question I have is this-- if this thing can only put out 15w per channel at 8 ohms, wouldn't we hear of folks finding they have little headroom before the thing starts getting blurry and smeary?  Was the room where they demonstrated it with KEF Blades so small that 15 watts was enough to get the KEFs singing? 

I'm just not sure how this thing could test out near 75w with that 15w Edcor OPT in mine from MusicDirect.

It won't.

As far as I can tell from the photos, that output transformer is a custom unit.

But its still a 15 watt device and will saturate when pushed beyond that level. The laminations in the transformer play an important role in how much power it can pass. The laminations are the magnetic core of the transformer and determine when it will saturate (no greater magnetic effect can occur). The wire plays a role too- it has to be able to handle the current at the power levels involved. But its mostly the laminations that say what power the OPT will be able to make. That is why higher power transformers are bigger and heavier.

I wish I didn't sell off my old PSBs, B&Ws, Monitor Audio, and hungry Totems. :)

@jbhiller That’s a great offer. I live in Florida so not feasible. As mentioned I came super close to buying this amp. My speakers are 86db 3 ohm and in a 30 by ..60ish room with 13 ft ceilings. It would have been a disaster. I came from two Carver C-500 amps vertically bi-amped. So while they were grainy on top and not the end of my road.. I was all bought in on Carver. Bitter sweet to see where its led. I was still keeping my eye out on used to see if I could pick one up, not now. Do love my current tube amps.. but there will always be that what if Changitis with this hobby. 

+1 Charles1dad. 

@funky54 , you are correct in that misrepresentations are unacceptable.  If someone is buying a 75w push pull tube amp for 84dB speakers with nominal impedance of 3 ohms I doubt they would ever look at this thing. But the Company did market it as going into 4 ohms at 75w.  

I'm just not sure how this thing could test out near 75w with that 15w Edcor OPT in mine from MusicDirect.  I have my doubts. But Bob has pulled rabbits out of the hat before and it indeed sounds good. 

I have only 3 audiophile friends within an hour's drive. They all have sensitive speakers. Does anyone with less efficient speakers live in Chicagoland and want to have me bring the amp by for a listening test? You could bring speakers here too, yet that's more work than lifting this light amp. :) I'd be curious to hear it with more demanding loads. 

 

I’m bothered by the view point that we should just gloss over the big covers over little 15w trannies or it making less than 25% of what its advertised to make because a few can still enjoy it with super efficient speakers in little rooms. 

Who is glossing over anything? Responses on this thread have been virtually unanimous in condemning the misrepresentation of amplifier output power? Even those who own/like the amplifier have been openly critical. 

Charles 

I’m bothered by the view point that we should just gloss over the big covers over little 15w trannies or it making less than 25% of what its advertised to make because a few can still enjoy it with super efficient speakers in little rooms. So their false advertising and sneaky use of big fake covers should excuse its non performance for those who may buy this amp and have it totally not work for them because of the misrepresented specs.

 

What about the guy in a 30 x 40 room with 3 ohm speakers rated at 84 sensitivity? Think he feels this amp is “sweet sounding”? There is just no excuse for it.

 

I have no doubt that it isn’t a wonderful 15 or 17 watt amp.. thats not the issue. The issue is All the other people who spend their hard earned cash only to receive something thats a lie and not help them or worse harm their current equipment.

 

Maybe Bob can remarket it as the Crimson -120 since its missing 120 watts? or how about the Crimson 2-60. I suppose the Crimson 215 or 217 could work.

Please note: this post is not related to testing but improving the amp.

Bob's response on the Carver forum identified R53 and R26 as doing the following: 

"Note that one end of the resistor is connected to amplifier ground, the other to the negative binding post.  Now just imagine what would happen if you connected the some test equipment to the negative binding post that turned out to be grounded to the amplifier ground.  That resistor is important.  It senses current going to the speakers and provides a signal into the feedback network that, among other things, reduces distortion in the amp."

As these are important resistors, I may swap them out and put in .1 ohm 5w Mills resistors, which are $4 each.  Why?  Because I'm nuts. :)

No one will tear it apart. It will be measured to see if it meets advertised specs. Those who like the amp why wouldn't you still like it? Still interesting to see how it does on the bench. 

@jjptkd,  Glad you are enjoying it.  Same here--my speakers are Cornwall IVs so my listening is not likely indicative of how the amp can pair with less sensitive speakers.  It had no problem though driving Wharfedale Linton Heritage speakers.

I bought one of these amps 6 months ago and absolutely love it-- great amp with a hefty bottom end and no complaints on power output but my speakers are 102db @ 1 watt in a 14x18 room. 95% of my listening is around 75db so I'm barely using any power. 

can o worms is right

holy moly

Yep! ASR crowd will tear this apart.

Charles 

Well, Bob has opened a can of worms. Grounding systems can be wily. I’m going to sit back and watch what ensues out there.

I do wholeheartedly agree with Bob in that the amp sounds big and sweet. It’s a fun ride regardless of what wattage it puts out.  [I do question that it can reach anything near 75 watts based on my teardown.]. 

 

From the Jim Clark forum-- They claim there's a special way to test them?
 

Carverfest Amps and how to measure them. A note from Bob. – Carver Stereo Forum


QUESTION: Bob, A guy is claiming a 275 makes 17 watts with strange distortion numbers any thoughts?



ANSWER: Thats ridiculous, a 75 watt amp.. Isn’t it obvious? It is being test wrong or its damaged.. My amps can be difficult to test, difficult to get the grounding correct. I’ve been dealing with people testing my designs wrong and getting grounding errors effecting measurements, most of my life.

@Charles1dad, I'm glad you understood what I was trying to convey.  I mean I have no beef against a great cap like WIMA.  Aren't they littered throughout nice products, like Audio Research, Pass, Vincent, and the list goes on.  

A Suntan?  Come on!  I bought WIMAs and AmTrans for the first tube amp I built and they hardly broke the bank.   

Hi djones51, Yes, you are correct. I think that I was suggesting there are measurement zealots who don’t put much stock in the subjective side.

By "beat out", I meant in my room, my system, my music, my ears. These amps were not bad, and, in fact, I said that I would recommend them in that post. The point was supposed to be (and I probably didn’t make it all that well), but testing and stats can be very important or, sometimes, not that helpful. I’ve owned a few products that tested in the tail of excellence side of the bell curve--yet I didn’t keep them because they were "beat out" by other things.

For instance, take the glorious and wonderful KEF LS50. I loved them and wish I had them around still to play with. But they didn’t work quite as well in my particular application than did the much less expensive Wharfedale Denton anniversary. This is why so many of the folks here always say try to audition or get a forgiving in home demo.

I have certainly seen folks chime in on ASR (who are new to those parts) and make a comment or ask about sound and they get pushed aside because that’s subjectivity and the product in question already tested poorly per their results. I was also pretty certain that in the ASR testing thread of the Carver that there was no talk or commentary on how the machine performed in use.  Maybe I am mistaken and someone on that thread who tested it used it with a couple of different speakers/preamps. I like hearing about people do that.  

Some old British roadsters test poorly but are a joy to drive! Same can be true with hifi. Sorry if I’m not great at making such points. Not trying to litigate this just explaining what I meant.

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.

What do you mean by beat out? 

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.  

Buying on stats alone won't tell you which amplifier you might prefer. I've read a lot of posts on ASR and I'm not aware of anyone especially Amirm that says buy on stats don't listen. Now if you make a claim that one amp measures or sounds better you will be asked if that's a personal opinion applicable to you or a general statement about the amplifiers themselves, if the latter you will be asked for your testing procedure. That's what a lot of people get wrong about ASR. There are members there who prefer tube amps, class A amps, lousy measuring speakers and DACs but they don't make universal claims about those products they know they're simply personal preferences.

@jbhiller 

The takeaway was supposed to be.... Why use Suntan at $.80 a cap?  Could they not use a better quality cap?  I mean what are you saving by using it versus a Wima or Vishay?  $5-10 per amp?

Fair and intelligent question , ×hat are you really saving in cost?

Charles 

Status update--The ASR guys have their Carver 275 now and testing should occur shortly.  The odds do not look good that it will test much much differently on specified wattage, but maybe, just maybe, the distortion results will be better. 

Yes, indeed they are Ralph.  It's just an exhibit in support of the point that Suntan caps are super cheap.  If a company's electrolytic blows up so easily how good can their even cheaper film cap be?  But for our education, yes a coupling cap is different than electrolytic AND this cap blowing up is not the same as the coupling caps in the Carver 275.  

The takeaway was supposed to be.... Why use Suntan at $.80 a cap?  Could they not use a better quality cap?  I mean what are you saving by using it versus a Wima or Vishay?  $5-10 per amp?  

It's a video of a Suntan cap blowing up.

Those are electrolytics, quite different from what is used for coupling caps in tube gear!

 

+1 JJSS49 on how we are keeping it cordial and respectful.  It makes the thread so much more informative and entertaining.  I love the differing opinions, especially those that differ from my own.  

@grovergardner , I didn't know that about console systems of yore.  Very interesting!

The original coupling caps in this unit were really unimpressive.  Take a look on my system page (even though the page is out of date), I have a pic of the original caps. They are the size of a fingernail!  There's a good bit of juice going through them per my tests and the schematic.  I really didn't like seeing that quality on such an important spot on the board. 

Take a look at this--same brand in the 275:   

 

It's a video of a Suntan cap blowing up.  Not acceptable in my book to use these.  You can always find an inexpensive but quality Wima, right?  Nelson Pass stuff is loaded with nice WIMAs and so are many other great brands. Why skimp here? Suntan? I wouldn't put it in an old guitar amp. :)

first i would say this thread is nice in that folks raising issues, and @jbhiller and i as current owners of these amps chiming in with thoughts and info, are keeping it positive and cordial - i think that is important, we can see other threads being much less so, and that can be become awfully unpleasant

second, i think to j-b’s comment about pricing of the 275, my own take is that the carver principal(s) were careful to choose their price point, knowing a higher one would considerably reduce their market interest, and i think that is also why they chose to skate on thin ice to write 75 wpc - that was the desired proposition: light amp, kt120’s, $2750 new, 75 wpc, drive most real speakers in real rooms to real volumes - thusly can undercut alot of the competition with a superior value propositon - whether they did this (the power rating specifically) ethically is a fair question -- for me, as an illustration, i bought the amp a touch under $2000 used - had it been a $4000 retail amp, selling for $3000 used, i may well have not gone for it

third, i would just reiterate that in my experience and use, i am not using super efficient speakers - spendor sp100 r2 @ 89 dbwm 8 ohms nominal, harbeth monitor 40.3 xd and shl5+ both @ 86 dbwm 6 ohms - in my 19x17 dedicated room, speakers well away from room boundaries - the amp drives all the speakers very well (i listen at low to mid 70’s db average with 80+ db peaks), has terrific bass response... not bass like a pass or a hegel, but roughly as good as much more expensive tube amps such as my audio research ref series -- how it does it, with xyz feedback circuitry, maybe it is managing the distortion, maybe it is playing some nice sounding distortion, but to my ears it works very well for a tube amp, sounds very good - good detail, excellent warmth and imaging, nice drive/prat - just what one would seek from a tube amp

last point i would add, and a bit of re-emphasis on what j-b said earlier, bob carver has always been an ’against the conventional grain’ type of character/designer in the audio world, he does things differently, thinks very much out of the box, so to speak... if one understands his long history (as i do, i have been at this as an avid hobbyist since the early ’80’s), he is never been shy to push the envelope -- more often than not, he can back it up... so we shouldn’t be surprised this amp with his name on it follows that tradition - importantly, at least in my case, the amp performs, making very good music to real volumes capably

all this said, the stated specs should be honest, and that may well be on bob carver himself, at his current ripe old age, or the folks running the business at present

I question whether it was as much about "cheaping out" as it was about creating a *lightweight* yet powerful tube amp.  Small couping caps notwithstanding (they've gotten a lot smaller these days due to better manufacturing techniques), I'd propose that the amp is an experiment in just that.  The design isn't sloppy, as Gordon pointed out at AK, there's a lot of tailoring to accomodate the small output transformer.  Another point of speculation over at AK is that the lower octaves are reinforced by harmonic doubling, much in the way that old console stereos used small, low-wattage amplifiers coupled with large, highly efficient woofers in a resonant cabinet to create the feeling of low bass, albeit at higher distortion levels.

I'm firmly on the side of honesty in marketing.  I've also been building my own tube amps for 20+ years now and finally learned to use an oscilloscope to see what's going on and improve my projects.  If I set out to build a 75wpc amp I certainly wouldn't be happy with those measurements, and would seek to improve them.  *That said* I'm curious to know if jbhiller has actually tried the amp in his big room, and if so, how it sounded.  Maybe the damn thing works, I don't know.

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.  

 

 

Oh you mean 4.5x more power… but in two channels with bass frequencies? Yeah, I’m sure the next one will do all that.

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.

 

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.  

@jbhiller

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.

@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. 

 

@jbhiller

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.

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.  

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:

carver_crimson_275.jpg

Look at resistor R53 and R44, connected to the negative speaker lead. That’s basically the same type circuit as the original Fisher 55A "Z-Matic" output-impedance adjusting circuit, just without the adjustability that Fisher provided (including the ability to turn it off, in the Fisher!). Here, it’s set to a fixed level of current feedback, reducing the damping factor. This will act to "color" the bass of most speakers- in a not-so-predictable way (each speaker has different impedance characteristics, which will interact with the network in different ways). This is ostensibly the "listening to the speaker in the room" thing that Carver was talking about, I would think. It’s funny, though, that it’s something that most experienced techs recommend REMOVING from the Fisher amps, since it’s rarely needed (unless you have very early speakers, designed for use with for amps with very low damping factors, such as 1950s JBLs, Altecs and such), and it’s rarely beneficial...

Also, more than one tech mentioned that they were struck by the myriad compensation networks needed for stability and response modification in this amp. Low-frequency shelving on the input (though switchable), HF frequency response limiting on the output of the first gain stage, LF shelving between the phase inverter and the output tubes, HF snubbing/shelving on the primaries of the output transformers, a Zobel on the output, AND a two-stage shelving network in the feedback loop itself, as well as the "output impedance modification" circuit described above. It’s rare for ANY amp to need THAT MANY different networks. Maybe two or three, tops- for example, the Eico ST70 "Hot Rod" uses three (plate-to-grid HF compensation on the phase inverter, HF snubbing/shelving on the OPT primary, and a Zobel)- but almost never SEVEN different response-modifying networks in one amp. I wonder what square wave response looks like, under normal operation, and also with each of those networks disconnected one at a time, to see exactly what each one of them is doing...

Mind you, having all those networks doesn’t necessarily mean the amp would perform badly or sound bad- but with each network added, there’s always the chance of "throwing away the baby with the bath water", in terms of sound. Every compensation network represents a compromise of some sort...

Regards,
Gordon.

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.

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 :)

@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. 

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

@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.