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Carver Crimson 275 Review (Tube Amp)

Rate this amplifier

  • 1. Poor (headless panther)

    Votes: 379 95.0%
  • 2. Not terrible (postman panther)

    Votes: 5 1.3%
  • 3. Fine (happy panther)

    Votes: 6 1.5%
  • 4. Great (golfing panther)

    Votes: 9 2.3%

  • Total voters
    399

mhardy6647

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Since "we" have been chattering about HD behavior recently in another thread here :)
One notes that the Crimson 275 does exhibit (up to failure) what I'd suggest is a "tube-like" amp distortion characteristic.

index.php



compare this to:


207cayin.7.jpg

source: https://www.stereophile.com/content/cayin-300b-integrated-amplifier-measurements
This a single-ended direct-heated triode (300B) amp with EDIT no NFB (see JA's comments in the link above -- I guess this amp has selectable and/or variable NFB; sorry I didn't grok that 'til now!).

Both are very different than the distortion curves "we" are used to seeing from push-pull, solid-state amplifiers operating in Class AB.


Given that this is a push-pull amplifier, @amirm one would expect the even-order harmonics to be largely cancelled out, so I don't think that the predominance of the 3rd order harmonic component in the distortion spectrum is unexpected.

BTW, I am a little puzzled by the data for the Carver amp in the borrowed figure above. It looks like the two channels (red and pink) are more or less superimposable -- why, though, are there two sets of red/pink paired curves? I am missing something... :(
The "lower" pair reminds me of the above-mentioned Cayin amp's distortion vs. power curves (FWIW).
 
Last edited:

mhardy6647

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Weird inteed to have a 3-wire IEC socket without connecting the ground.
They could've used a two-conductor socket if there were no intent to ground the chassis -- or just use a captive (hardwired) two-wire power cord!

The "loose screw" is troubling -- I do hope that neither "The Bob Carver Corp." nor disappointed/disgruntled Crimson 275 owners invoke it as a deus ex machina to explain the measured performance! :confused:
 

paulbottlehead

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The "loose screw" is troubling -- I do hope that neither "The Bob Carver Corp." nor disappointed/disgruntled Crimson 275 owners invoke it as a deus ex machina to explain the measured performance! :confused:
One output transformer appears to be missing a screw to hold it down, but it can't be that screw since the nut is on the chassis side and the screw would be rattling around inside the shroud.
 

Celty

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Wow for that much money you could could get a very nice tube amp, let alone a solid state design.
 

paulbottlehead

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Truly dismal. Got a strong suspicion Bob Carver didnt design this.
I feel it's important to point out this link, allegedly with some context from Bob Carver:
https://carverstereoforum.com/forums/topic/carverfest-amps-and-how-to-measure-them/

"QUESTION: Bob, how can a 75 watt tube amp use such small output transformers and be lightweight ?

ANSWER: I’ve always designed amplifiers that had lots of power and lighter weight than others designs. The transformer size can be made smaller by using fine wire and specified materials. There is no magic, because it adds inefficiencies in other ways like power, but the design has more than enough power.

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."
 

Billy Budapest

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Glad to see you back!

I wasn’t expecting much measurement wise but I was really let down by the safety, QC, and cost-cutting issues plaguing this amp from this legendary brand.

Makes me wonder how the newly-reborn (relatively, at least) Dynaco and Hafler amps are built and how they measure.
 

kencreten

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But not surprising considering the size and rating of the output transformers. As to the lack of earthing...

S
I don't know how to judge what you're saying.... I do understand that grounding is necessary, and appropriately sized transformers are needed, but those speaker cables? $2500 loose stuff inside. Ouch.
 

norcalscott

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Thanks for testing this Amir with all the other issues you are dealing with at the moment.

What a let down, what a piece of absolute crap for the money - Jim Clark and anyone else who helped perpetuate this scandal should be ashamed. Maybe he will come back to this thread to apologize to everyone? (I doubt it...) Hard to believe Bob Carver was involved in this, but the profit margin on this must be huge so anything is possible.
 

Digital Mastering System

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I feel it's important to point out this link, allegedly with some context from Bob Carver:
https://carverstereoforum.com/forums/topic/carverfest-amps-and-how-to-measure-them/

"QUESTION: Bob, how can a 75 watt tube amp use such small output transformers and be lightweight ?

ANSWER: I’ve always designed amplifiers that had lots of power and lighter weight than others designs. The transformer size can be made smaller by using fine wire and specified materials. There is no magic, because it adds inefficiencies in other ways like power, but the design has more than enough power.

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."
Maybe Amir can call up Bob and have him come over to fix up the test procedure. Doesn't Carver live in Seattle too? (I'm not serious.)
 

SIY

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Since "we" have been chattering about HD behavior recently in another thread here :)
One notes that the Crimson 275 does exhibit (up to failure) what I'd suggest is a "tube-like" amp distortion characteristic.

index.php



compare this to:


207cayin.7.jpg

source: https://www.stereophile.com/content/cayin-300b-integrated-amplifier-measurements
This a single-ended direct-heated triode (300B) amp with EDIT no NFB (see JA's comments in the link above -- I guess this amp has selectable and/or variable NFB; sorry I didn't grok that 'til now!).

Both are very different than the distortion curves "we" are used to seeing from push-pull, solid-state amplifiers operating in Class AB.


Given that this is a push-pull amplifier, @amirm one would expect the even-order harmonics to be largely cancelled out, so I don't think that the predominance of the 3rd order harmonic component in the distortion spectrum is unexpected.

BTW, I am a little puzzled by the data for the Carver amp in the borrowed figure above. It looks like the two channels (red and pink) are more or less superimposable -- why, though, are there two sets of red/pink paired curves? I am missing something... :(
The "lower" pair reminds me of the above-mentioned Cayin amp's distortion vs. power curves (FWIW).
The Cayin is not comparable because of its topology (which is what determines that distortion curve). This Carver amp would likely clip in the usual push-pull manner if it didn't blow fuses before its clipping point.

edit: I wish I knew where my little EL84 amp is buried. I'd love to post some comparative measurements...
 

NiagaraPete

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Happy to hear you’re dry again and sorry to hear this all happened.

As for the Carver I’m not surprised I don’t think that company ever made anything good. My opinion.
 

L0rdGwyn

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Instead, there is some kind of local, star grounding referenced to neutral using a resistor. That naturally won't work for safety purposes. With that power supply board mounted vertically with voltages as high as 300+ volts, I sure as heck would want this metal case grounded.

685V on the plates of the KT120. Watch your fingers.
 
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