Carver Crimson 275 Review (Tube Amp)

[jbhiller]

I am not defending Jim nor any of the people you mentioned.
The measurements and build quality are well documented in this thread.

My questions to you are simple.
Have you asked the dealer you purchased the unit from for a refund?
Are you just venting or are you seeking further restitution?
Did the perceived "sound" change after you opened up the unit?

I modified the unit so I haven't asked the dealer. Nonetheless, I would think anyone would be entitled to a refund given the misrepresentations and the safety issue presented by the lack of chassis ground.

You can call the emotion side of my post what you want. I think it is sad because Bob Carver is an important figure in the hifi field. I like him. Maybe, and I'm speculating, Bob (like Mark Levinson and others) once again sold his name and the results may not be in keeping with the original intent and design of Bob Carver. I think it is also sad from the misrepresentations and build quality perspective. Consumers should not have to have electrical experience or a degree to perform their due diligence on an amp they want to purchase. This, in 2022, by an American company, for a product made in America, with Bob Carver's name on the product--to me (and you may dislike my subjectivity)--is just plan sad.

The process of opening up the unit had and has never had a change on an amplifier's sound--except for a limited experience of mine where a wire was caught and shorting on something I opened up in the 1990s, whereby the signal was restored.

 

[jbhiller]

It is entirely possible that Carver (the man) designed the circuit the 275 is based on but then had nothing to do with the decision to use 15 watt transformers and with the failure to meet Type I wiring requirements.

Billy B, that's my view: Not that this is the case but that it is entirely possible.

 

[jbhiller]

It is also entirely possible that folks that heard this amp driving KEF Blades at a Florida audio show, AXPONA, Capital, etc., heard a different animal.

 

[Zackthedog]

There's also no excuse in 2022 to use a cathode resistor in the phase splitter, then unbalance the plate resistors to make up for it.

Well, that's the way a long-tailed pair phase splitter is constructed.

The Long-Tail Pair

Guitar amplifiers

www.aikenamps.com

ETA: Or maybe you mean there's a better way to balance the pair, like a negative supply or current source?

 

[GimeDsp]

They saved money on welded stand offs to provide you with an extra screw to use as you wish.

 

[jbhiller]

They saved money on welded stand offs to provide you with an extra screw to use as you wish.

HA! Thank you for making me laugh.

 

[Billy Budapest]

It is entirely possible that Carver (the man) designed the circuit the 275 is based on but then had nothing to do with the decision to use 15 watt transformers and with the failure to meet Type I wiring requirements.

And for the record, I own a pair of Sunfire CRM-2’s—very interesting speakers designed by Bob—but have never owned any other Carver, Sunfire, or Bob Carver Company products. Or Phase Linear for that matter.

 

[Billy Budapest]

They saved money on welded stand offs to provide you with an extra screw to use as you wish.

I’ve seen a few amps wherein the chassis ground is attached to a welded stand-off (via a screw screwed into the top of the stand-off). Not sure if that would meet Class I requirements due to potential incomplete ground path at the weld connection to the sheet metal.

 

[SaltyCDogg]

Good Morning, afternoon or evening:

I was really hoping this thread would tighten up with less negative sniping.
Graphs, measurements and true electrical circuit knowledge carry more intellectual weight than the drive by "this is a piece of garbage."

There are way too many posts mentioning the lack of response from Carver employees.

A few of the members mentioned their level of business acumen and experience.
Those individuals should know that a 'corporate response' is a well worded and measured release.
I don't know of any company that would respond once phrases such as class action, regulators, dangerous
are used in context of their product - without investigating the claims and having their council review the findings.

I would assume that the dealers would have the information/remedies first. This would allow them to reach out
to people that actually own their product.

So - let's be patient and wait for a response from a representative.

I find it amusing that this forum doesn't meet your standards. It's one of the most civilised that I'm a member of. Most people are on here for their hobby/entertainment. Your repeated attempts to try and moderate people's responses are doomed to failure.

 

[MakeMineVinyl]

Indeed! Here's an example:

View attachment 179721​

That is quite common, believe it or not even in some professional gear of the period (like the electronics section of the Ampex 602 professional portable tape machine). However there were others like McIntosh and Marantz which used very orderly wiring with turret boards and nicely laced cabling.

 

[sarumbear]

And for the record, I own a pair of Sunfire CRM-2’s—very interesting speakers designed by Bob—but have never owned any other Carver, Sunfire, or Bob Carver Company products. Or Phase Linear for that matter.

CRM-2 is wishful thinking design. Forget that acoustically it’s a bad solution, it says on the manual they they are bipolar speaker, which is wrong as they are wall mounts!

 

[john2017]

Billy B, that's my view: Not that this is the case but that it is entirely possible.

That is my view as well. The Bob I know is intensely a man of his word, almost to a fault. If he said the amp was 75wpc, it was easily doing that and more. When a shitbird like Frank Malitz gets his paws on it, then all bets are off. I trust Bob's work, but cannot recommend anything that comes from the company bearing his name so long as Frank Malitz is at the helm.

 

[SIY]

ETA: Or maybe you mean there's a better way to balance the pair, like a negative supply or current source?

Yes, there's plenty of compliance available for a simple CCS, which will automatically balance the stage irrespective of differences between tubes, assuming equal plate resistors. Two FETs and 4 resistors or a bipolar, two resistors, and a LED. Maybe $2 in parts.

Of course, the input and phase splitter weren't designed so much as copied straight out of numerous 1950s amps.

 

[Gringoaudio1]

As someone who designs electrical equipment the lack of proper grounding scares me. And a company that forgoes UL testing is just plain Mickey Mouse or a simply hobby-scale startup. Even then don’t start up if you don’t have the funds to properly certify equipment that could kill people. Carver is big enough that they should be selling UL listed products. You do not have to have things UL approved to sell them but it is the legitimate way to operate. This is irresponsible and unsafe and the liability they incur by not testing is dangerous to the viability of the company itself! I doubt there are shareholders but if there are they should be informed that their investment is at great risk.
And this is not even mentioning the fact that it is a piece of shit specifications wise.

 

[Larry B. Larabee]

Does anyone know for a fact that the 0.1/3w (r53) isn't used as a test point to set the bias? And the meter probably has an offset trim to be calibrated from the voltage drop reading on r53, too. Possible?

 

[paulbottlehead]

There is. The enclosure is even connected to it.

The enclosure is not earthed. It is tied to mains neutral through a 5M resistor though.

 

[paulbottlehead]

Does anyone know for a fact that the 0.1/3w (r53) isn't used as a test point to set the bias? And the meter probably has an offset trim to be calibrated from the voltage drop reading on r53, too. Possible?

R53 is not used to set bias.

 

[Greg P]

Good Morning, afternoon or evening:

I was really hoping this thread would tighten up with less negative sniping.
.......

My observation is that one constant here has been your non-stop complaining about what others here are saying. You said your piece: the amp sounds fine to you and it doesn't matter to you how it measures. Good. Everything else is your picking at others for what they have to say, most of which has nothing to do with you except when you hassle them for saying it.

 

[alashikata]

No surprised there is noise in the power supply because there is no choke. I believe in this review and there is something wrong with this amp. Not sure why the terminal speaker wires are small All my tube amp that has big wire (18 AWG?) connect direct to speaker terminal from OPT wires.

Watch his channel (Skunkie Designs Electronics), he has to mod those chinese tube amps to improve the sound and measurement and overrated power where he did to correct it.

Boyuurange / Reisong A50 300B

The same problem with VTA M125 monoblocks that two people pointed out that others didn't know, then he got banned from the forum for speak out.

Dynaco VTA M125 problem and measurement
http://ielogical.com/Audio/VTA_M-125.php

Actually 30 watts tube is loud. It won't blow out the windows as Mark Levinson 532 amp but would get you deaf in a few days if you turn to max.
My 300B PP 20w and KT88 PP 30w (KT88 advertise as 60w but the measurement is around 50w UL) can drive JBL Everest DD67000 easily and I only turn at 1/3 volume

 

[Doodski]

Wowow. ASR is becoming tubular.