Carver Crimson 275 Measurements

[paulbottlehead]

If I was the owner of these, and found out, I'd be on the horn to Carver. If what I had was not broken, I'd be demanding my money back. If that wasn't forthcoming, I'd be on the phone to my state consumer protection agency.

I definitely had a discussion with my boss about these numbers, as well as a local corporate attorney who assured me that as long as what I'm posting is accurate and I say nothing subjective, I'm all in the clear. This means I will not even be listening to these amplifiers, I will not comment on perceived parts quality, or even any potential safety issues or anything like that. Only data!

 

[mhardy6647]

Can we say that? I've seen many measured reviews of Carver gear over the years, but never anything like this. What we know is that a new member of the forum, with no history, posts a very troubling review. Yet we have no background about the gear in question. Where did they come from, how were they bought, how old are they, was any attempt made to contact the dealer or the manufacturer? Many questions, few answers.

I encouraged the poster to share these data here, for what it's worth and for better or for worse. The data are the sort of "information" that sends adolescent-girl-style shockwaves through and between forums (and I do apologize for my sexist but I'd argue apt metaphor). I suggested ASR as a good place to share the data. As @paulbottlehead says in the OP, he was surprised and intrigued when he first hefted the amp, so I don't think there's any premeditated ill will on anyone's parts.

Some of us have been curious about this amplifier for a long time -- I came very close to buying one when they were introduced with special pricing ($2495). A good performing pp vacuum tube 75 wpc stereo amplifier at that price would be a good deal for anyone with hard(ish) to drive loudspeakers -- and even I have a few of those! The more I thought and read about the amp, the more skeptical I became -- and I'll cop to being pretty skeptical of Bob Carver historically, although I have to agree that he's apparently delivered the goods on numerous occasions. I'll also note loud and clear that, in terms of credentials, I have none.

I am not at all sure that these amps are actually so rare "in the field", but there's just not much reliable information, even audiophile-style "reviews" on the interwebz -- which, again, is perplexing.

I honestly don't think there's any agenda except interest in what makes these unusual little amplifiers tick.

EDIT: FWIW, I don't think the identity of another forum that may not have wanted to host a post or thread containing the data in the OP is really a good topic to discuss "publicly" anywhere. That whole "forum war" thing is usually pretty unseemly.

 

[paulbottlehead]

I will add this here. I am not going to say anything about this photo, it's just something to look at.

 

[Larry B. Larabee]

Thanks, Paul. Now that I know you're a professional what about the circuit design do you suppose would account for this horrible performance even by tube standards. What do you think Carver did wrong? Assuming both amps are not broken for some reason, I mean.

thanks

 

[mhardy6647]

In a less political vein

I wonder if the EDCOR iron is off-the-shelf or custom wound for Carver?
I would not at all be surprised if it's the latter.
I know of EDCOR but I've never used any of their transformers for a project, so I am not at all familiar with even their stock products nor part numbers.

 

[Schollaudio]

Can we say that? I've seen many measured reviews of Carver gear over the years, but never anything like this. What we know is that a new member of the forum, with no history, posts a very troubling review. Yet we have no background about the gear in question. Where did they come from, how were they bought, how old are they, was any attempt made to contact the dealer or the manufacturer? Many questions, few answers.

Again, if what we have been shown is representative of Bob's current product, then it's a very sad day indeed. Sad for Bob, his company, and consumers who trusted him over the years, and bought his gear. But we really don't know that for sure. Until the questions are answered, until we know more, I think caution is in order.

I would like to agree with you but the weight is the tell. 19lbs, a proper set out outputs are 6-8lbs each. The VTA ST120 is 42lbs shipping for at least 35lbs.

 

[tmtomh]

Thanks, Paul. Now that I know you're a professional what about the circuit design do you suppose would account for this horrible performance even by tube standards. What do you think Carver did wrong? Assuming both amps are not broken for some reason, I mean.

thanks

He just explained that, after consulting with his boss and company attorney, he is not going to provide commentary or opinions on this amp, just data and photos.

 

[paulbottlehead]

In a less political vein

I wonder if the EDCOR iron is off-the-shelf or custom wound for Carver?
I would not at all be surprised if it's the latter.
I know of EDCOR but I've never used any of their transformers for a project, so I am not at all familiar with even their stock products nor part numbers.

The "EM" is I believe "Equipment Manufacturer" and would be a custom design.

 

[paulbottlehead]

Thanks, Paul. Now that I know you're a professional what about the circuit design do you suppose would account for this horrible performance even by tube standards. What do you think Carver did wrong? Assuming both amps are not broken for some reason, I mean.

That probably crosses a line I shouldn't cross.

Regardless, the pictures of the output transformers say "15W". Edcor calls them 15W transformers. I measured about 15-17W.

 

[Larry B. Larabee]

He just explained that, after consulting with his boss and company attorney, he is not going to provide commentary or opinions on this amp, just data and photos.

Those were posted while I was typing.

 

[anmpr1]

I just assumed that Carver would have a small well trained crew, utilizing SOA (or at least industry standard) assembly. It looks like it's all hand soldered in his basement. The kind of thing Julius Futterman was doing in his Manhattan apartment, 50 years ago!

FWIW, if tubes are your thing, and if wiring by hand is what you want, just get a kit, and do it yourself, for crying out loud. You'll have fun, and no one will make fun of your home made efforts, but admire you for trying something new.

 

[mhardy6647]

In fairness, I am pretty sure that the current Bob Carver business is a pretty small operation -- and, presumably, by [his] choice.

 

[paulbottlehead]

Just as another data point, I did measure one of these a few years back:

The thing made 42W at 32Hz with decent THD, that was a pleasant surprise!

 

[Blackdog]

Saw a reference to this thread on another forum, so I had to join.
I've been inside one of these amps when they first came out. The dealer I got it from couldn't believe a tube amp could be this light, so asked if I could check them out.
My numbers pretty much corresponded to what Paul has published here. I unfortunately don't have the charts, and data sheets any more.
Needless to say the dealer never stocked another one.

 

[paulbottlehead]

Saw a reference to this thread on another forum, so I had to join.
I've been inside one of these amps when they first came out. The dealer I got it from couldn't believe a tube amp could be this light, so asked if I could check them out.
My numbers pretty much corresponded to what Paul has published here. I unfortunately don't have the charts, and data sheets any more.
Needless to say the dealer never stocked another one.

Thank you Dan!

 

[anmpr1]

Just as another data point, I did measure one of these a few years back: The thing made 42W at 32Hz with decent THD, that was a pleasant surprise!

There is no reason that a tube amplifier can't meet it's published specs. Or that it can't be powerful enough... even for difficult to drive applications. Likewise, there is no reason that Bob Carver can't make a powerful enough tube amp for difficult situations. One that can meet specs. Bascom King's review of the original Silver Seven tube amp demonstrated that.

But this? What a disappointment. I always admired Bob. But I don't even think Miss Hologram would put up with this latest thing.

 

[Larry B. Larabee]

View attachment 174257
I will add this here. I am not going to say anything about this photo, it's just something to look at.

If this photo is for me things may start to be making sense! thanks.

 

[paulbottlehead]

If this photo is for me things may start to be making sense! thanks.

You'll have to PM me what you're after, as I suspect you're three steps ahead of me and I need to catch up!

 

[SIY]

IME, Edcor makes good low cost iron. And Roger Modjeski claimed that transformers can be made significantly smaller these days because of improved materials. But this might be a bit of a stretch.

Usually, small high quality transformers can do multiples of their power ratings at frequencies well above low bass. For example, I use some James output transformers for my amp running the top section of my speakers (>120 Hz) that are rated at 15W, but they have no trouble in this application of achieving 45W. No way they could do it at 20 Hz.

 

[paulbottlehead]

Well, wiring insulation has come a long way, and you can fit more turns in the winding window now than you could 50 years ago because the insulation is thinner. This insulation is also far more tolerant of heat stress, so a modern power transformer can be run hot to the touch and the internal wiring still has a substantial amount of thermal headroom remaining. We do have more variety of lam alloys available as well, though some of that stuff gets very expensive very quickly.