Carver Crimson 275 Review (Tube Amp)

[BDWoody]

The Edsel was a very decent and well-built car for its time. I think that the Yugo is the better comparison....

Or the Ford Pinto?

 

[pkane]

I had hoped your response would have only included the second sentence.
That would have been sufficient.

Your passive aggressive anger is misdirected. Direct it to your amp dealer or manufacturer for selling and producing a sub-par product that misses their own specifications (by a mile), appears to be poorly made and ignores basic safety principles. Nobody here is responsible for this mess.

 

[SIY]

Thanks for that. Another valve fave (for reviewers: I"ve never heard one) was the Michaelson & Austin TVA.

Life expectancy measured in minutes. Man, I fixed those again and again.

 

[traderitch]

I will give you the benefit of the doubt that your intent is not to be a troll.

Not a troll = I have a vested interest in this

 

[traderitch]

Your passive aggressive anger is misdirected. Direct it to your amp dealer or manufacturer for selling and producing a sub-par product that misses their own specifications (by a mile), appears to be poorly made and ignores basic safety principles. Nobody here is responsible for this mess.

I have no anger. I was merely seeking answers to the questions I had asked.
The initial site measurements were validated and the amp still serves its intended purpose.
The questions of safety were most important to me.

 

[Thermionics]

Many of these commercial tube amplifiers really do feel like cash grabs. Like moths to the flame, the audiophiles are drawn to the glow of the tubes! But when I look inside the mostly empty chassis...where is the power supply regulation? Active loading? Proper layout and grounding? I am no engineering genius, these things are simple to implement, low cost, and drastically improve performance. The best tube amplifiers are being made in the DIY arena, in my opinion, where one doesn't have to worry about profit margins and can afford to add a $20 voltage regulator to a design. Maybe even properly rated output transformers. These commercial tube amplifiers are giving my dear tubes a bad name.

Bottom of the photo of the underside - looks like a standard two-diode CRCRC B+ supply. Nothing exotic.

 

[Blumlein 88]

I really appreciate your response. I do not believe one should be flippant in response to an inquiry related to safety.

As far as IEC three pin sockets not being chassis earthed. My personal observation of modern audio equipment is the third pin is not being used as you can see in in this Marantz AV8805 (reviewed here in February 2019)

Those are double insulated. The Carver is not.

 

[Thermionics]

The inside looks pretty scary from a safety standpoint. AC wires nicely rubbing against sharp PCBs and untrimmed soldered leads. High voltage leads it looks like soldered to pads, not with a through-hole in some cases. It looks sub-DIY.

@amirm , you mentioned you had to ground the AP to measure. With that bizarre neutral connection in the amp, is there potential that caused issues with the low frequency measurement?

If you are talking about the twisted-pair of brown wires, that'd be the 6.3VDC heater supply. B+ for the plates is (I think) the twisted-pair of blue wires which looks to be through-hole. However, looks a bit kit-amp-ish.

 

[SIY]

Bottom of the photo of the underside - looks like a standard two-diode CRCRC B+ supply. Nothing exotic.

If the photo of the power transformer earlier in the thread is accurate, it's a doubler. Also non-exotic, but nothing wrong with that.

Grossly under-rated transformer for the claimed power, naturally.

 

[Blumlein 88]

I appreciate the response - the page count of this thread would be cut in half and the informative content would be much more beneficial had people been less emotional and more substantive - like you

Answer this question for me as an Owner.

If the amp had been properly advertised as having 15 wpc, would you have purchased it? I would think you wouldn't have even considered it at such a power rating.

@traderitch

BTW, people fail to consider the logarithmic nature of power versus loudness. I once picked up an old Fisher intergrated with EL84s. Roughly 17.5 wpc. On some Quad ESL63s it played it not badly at all. The high impedance at low frequencies of the Quad helped. It even did okay on other normal speakers. It fell flat on its face with large ported speakers.

 

[Thermionics]

If the photo of the power transformer earlier in the thread is accurate, it's a doubler. Also non-exotic, but nothing wrong with that.

Grossly under-rated transformer for the claimed power, naturally.

Good call. I couldn't see how the circuit was laid out given the orientation of the PCB. Nothing wrong with a well-designed doubler, provided it meets spec.

 

[Blumlein 88]

BTW, on USAudiomart currently there are several early C-J and ARC tube amps at 45 to 100 watts for the price of this Carver or less, sometimes quite a bit less. Some of them have already been re-capped by the current owner and would last many more years.

 

[amirm]

Possible, but anyway you look at it, after these measurments there won't be any sales from this community, regardless of what they can come up with to defend them.

What "community?" We have nearly 3 million visitors a month. Don't just look at who is posting. That is a tiny fraction of who reads our content. People search for "carver crimson 275 review" and land here. And will read what is posted.

 

[amirm]

And where would a layperson see this "safety ground"?

All of your questions were clearly addressed in the review. Did you not read it? I post pictures, put notes on the pictures and explained in text the safety and quality control issues.

 

[Larry B. Larabee]

OK. I'll bite. This is a crop of a picture from post #1. You can see that there are wires carrying 120 VAC soldered to tabs of the switch, PCB, fuse holder, etc. If one of them came loose, it may short 120 VAC to the chassis. This is a single point failure that can cause the chassis to become a lethal hazard, and is a huge no-no.

View attachment 179512

Proper construction technique would dictate looped and crimped wires on a through hole terminal connector.
That's what counts, a good mechanical connection is as important as the soldering, I bet the same person who built it probably QCs the products by sticking his finger on one of the input terminals and listening for a hum from the speaker (ala Rappoport-an inside joke!).

 

[L0rdGwyn]

Good call. I couldn't see how the circuit was laid out given the orientation of the PCB. Nothing wrong with a well-designed doubler, provided it meets spec.

Yes, it's a doubler. There is a full schematic in the manual which was linked in the original measurements thread.

https://carverstereoforum.com/wp-content/uploads/2018/10/Crimson-275-Owners-Manual-REV100.pdf

 

[traderitch]

All of your questions were clearly addressed in the review. Did you not read it? I post pictures, put notes on the pictures and explained in text the safety and quality control issues.

I apologize.
I really should have reflected back to the original review. I became fixated on wading through all of the comments and replies.

 

[Larry B. Larabee]

Hey, Paul.
C4 and C19 caps were missing in both of your Carverfest amps. I see they are included in the factory version.
Can you pop some in your amps and see if makes any difference. No telling why they would be missing in the first place.

Sorry,Paul. C4 and C18 not C19

 

[Greg P]

..... I guess age gets to the best of us, and now Bob's mind is going.

That's over the top.

 

[vkhong]

Sorry,Paul. C4 and C18 not C19

On my Crimson 275 Stereo:
C4 not used
C18 used
C19 used