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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

JJB70

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I think the reason this is so painful is the Carver name. Bob Carver isn't (or at least he wasn't previously) some snake oil selling charlatan or clueless amateur soldering embarrassing junk together in a shed like many boutique audiophile-ish people. He is an extremely talented, capable man who probably did more than anyone individual to demonstrate the emperor's lack of clothes. To see him sell his name to something like this is painful. Painful. Blowing a reputation built over a lifetime for a few bucks, how sad is that?
 

Vovgan

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Output impedance is high enough

Chief, is my reading of the THD+N chart correct in that this amp produces 5W with 0.2 volts of input signal? Is there a formula to calculate output wattage from input voltage knowing resistance? P = V2/R clearly gives a different result. Thank you!
 

CDMC

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I think the reason this is so painful is the Carver name. Bob Carver isn't (or at least he wasn't previously) some snake oil selling charlatan or clueless amateur soldering embarrassing junk together in a shed like many boutique audiophile-ish people. He is an extremely talented, capable man who probably did more than anyone individual to demonstrate the emperor's lack of clothes. To see him sell his name to something like this is painful. Painful. Blowing a reputation built over a lifetime for a few bucks, how sad is that?
This. His TFM and Magnetic Field amps were a good value, as were Phase Linear. The Sunfire I had for years was a wonderful beast, powerful, dead silient, and cool running.
 

dshreter

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Chief, is my reading of the THD+N chart correct in that this amp produces 5W with 0.2 volts of input signal? Is there a formula to calculate output wattage from input voltage knowing resistance? P = V2/R clearly gives a different result. Thank you!
That’s because it is an amplifier, it is amplifying the power and isn’t simply the input voltage fed into a resistor.
 

YSC

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This is a review and detailed measurements of the Carver Crimson 275 tube stereo power amplifier. It was purchased new by member @paulbottlehead and given to me for testing. It costs US $2750.
View attachment 179227
I really like the way the amplifier looks. The burgundy color is attractive as is the handle. On the latter, the unit is very light though so the handle while handy, is not necessary to lift the thing. Back panel shows high quality connectors:
View attachment 179230

The tubes, four Tun-sol KT120, pair of 12AT7W and 12AX7 can in their original boxes for the owner installation. Went to open one of the small tube boxes but found nothing in it! Worried, I looked around and it had come out of its box and was just floating in the larger box that they all came in.

Prior to installation of tubes I had something to investigate: there was clearly something loose in there, rattling around. So I took the back panel off to find a metal screw rolling around in there:

View attachment 179235

Not sure where it was supposed to go. There is a hole for something above the second fuse from the bottom but I think that would for a nut.

I did not like lack of safety (earth) ground from the IEC terminal:
View attachment 179238

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. I don't care what audio/electrical problem they were trying to solve there. I want a safe product first and foremost. Naturally there is no safety/regulatory certification which I expect a company with the name "Carver" to be able to afford.

I got a kick out of the beefy speaker terminals but ultra-thin wires leading to it! Yes, the lengths are short and at this wattage is probably fine but from "optics" point of view, you would want to use something better than hair thin wiring (see gray and red wires).

I was sad to see the VU meter glued to the case:

View attachment 179239

I realize welding a couple of threaded stand-offs to the case costs money but at this price, I expect such. The meter is not backlit which was another disappointment. But was useful for checking bias which was right at the spec at 100 milliamps.

So nice looks but under the skin, a number of concerns.

Carver Crimson 275 Measurements
I usually let amplifiers warm up some and watch their behavior and also let things stabilize before measurements. Manual states that bias can be checked after 20 minutes so I let it run for that long and a bit more:
View attachment 179241

Note that the vertical scale is only 3 dB so don't be alarmed by the variations. Generally speaking, unit is table after a couple of minutes of warm up. But it is fascinating to see performance gradually get worse as it kept warming up (again, at micro level).

So next comes our usual dashboard. My Audio Precision analyzer by default has floating (non-earth connected) RCA terminals. But I had to override that by grounding it as I observed oscillations (frequent occurrence with some amplifiers). No other attempt at grounding made a difference in power supply/mains hum:


View attachment 179242

The power supply noise really dirties up the FFT spectrum but looking past that, we see that the low SINAD (sum of noise and distortion) is dominated by distortion. Unlike the common reputation for tubes, distortion is third harmonic for the most part, not second. Naturally the high level of distortion places the 275 very low in our scale, second only to one other amp ever tested:

View attachment 179243

Company spec is quite good for noise level relative to full power. I could not get that without a-weighting:

View attachment 179244

But applying the a-weighting filter and with it, getting rid of power supply noise, we do essentially get there:

View attachment 179245

Crosstalk was poor:
View attachment 179246

Frequency response has an odd shape and good bit of loss at high frequencies with 4 ohm load:
View attachment 179248

Output impedance is high enough that is combining with the load to change the high frequency roll off. Things get better as such with an 8 ohm load:

View attachment 179247

There is an RC filter on the speaker terminals. Wonder if that is what is providing the roll off.

Using 32 tones to simulate "music" we see a high level of "grass" which would obscure any low level detail:

View attachment 179249

Notice how the worse performance is in low frequencies.

There has been controversy regarding ability of the 275 to produce its rated power of 75 watts so let's start with 4 ohm load as I usually do:
View attachment 179250

The amplifier produced 29 watts after which it blew its 3 amp mains fuse. Fortunately two spares were provided, allowing me to continue testing. Company specs distortion at "less than 1%" so let's see power at that rating:
View attachment 179251

Very dramatic difference between 1 or 2 second power (used for left side) vs short bursts. There is clearly a capacity problem to produce sustained power. Note that this is at 1 kHz as is industry convention. Note that allowing just 1% THD reduces the power even more than what I allowed in my power sweep.

I was surprised to not see selectable output impedance for 8 ohm load so proceed with the test as is:

View attachment 179252

We blew the second fuse but now power is much more healthy at 60 watts.

Hoping to not blow the last fuse, I kept the max power level lower as I changed frequencies:

View attachment 179254

Performance was "reasonable" (for at tube) but once we got down to 20 Hz, it became super erratic and blew the third fuse. :( It produced only 14 wats which is well short of 30 watts it produced at higher frequencies. I would have wanted to test at more frequencies but it was past midnight and I did not feel like hunting around to find my own replacement fuses.

Conclusions
As a Carver owner of 40 years (solid state), I have a soft spot for the designer. Alas, while I like some things about this amp like the nice looking paint, I am very disappointed in the QC and construction of the unit with respect to safety. Loose screws and glued meters should not be part of a nears $3,000 amplifier. Measured performance is awful of course and one would expect that for many audiophile tube amps. But having third harmonic be dominant blows away the story of why that is audibly a good thing. Clearly the specifications of the amplifier is incorrect for 4 ohm load (company even allows usage for 2 ohm loads!). And low frequency behavior is very poor.

Unless you are going to buy the Carver Crimson 275 to just look at it, I can't recommend it for many reasons stated above. I expect more from the man, the legend....

P.S. It was nice to take a break from drying up our flooded home and get back to some "normalcy" with testing this amp. It cheered me up to be "working" again and doing what I enjoy.

-----------
As always, questions, comments, recommendations, etc. are welcome.

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Scroll through the look and SINAD I was about to give it a not too broken rating as that’s how tune amp behaves, then saw the price and the safety plus build quality… can we have a completely broken or shattered panther rating?

P.S. is your home fixed and well now?
 
OP
amirm

amirm

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P.S. is your home fixed and well now?
Oh, no. Spending all day cleaning, sucking up water, moving fans around, etc. The source of water coming in seems to have been taken care of which is good. We will see if it holds when the rain returns on Tuesday.
 

YSC

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Oh, no. Spending all day cleaning, sucking up water, moving fans around, etc. The source of water coming in seems to have been taken care of which is good. We will see if it holds when the rain returns on Tuesday.
Wish you all the best, just imagining the size of an average American house and all those soaked and ruined wooden floor and carpets needed replacement, even letting heart breaking spendings it’s a hell of a pain in the back (literally) work for anyone after their 30s
 

ROOSKIE

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I think the reason this is so painful is the Carver name. Bob Carver isn't (or at least he wasn't previously) some snake oil selling charlatan or clueless amateur soldering embarrassing junk together in a shed like many boutique audiophile-ish people. He is an extremely talented, capable man who probably did more than anyone individual to demonstrate the emperor's lack of clothes. To see him sell his name to something like this is painful. Painful. Blowing a reputation built over a lifetime for a few bucks, how sad is that?
Well now that he is free, maybe Bob will be free pick Novak Djokovic up at the airport.
 

DanielT

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What the man in question thinks about it:


Edit:
As I said, as others have pointed out in this thread. If you are going to have a tube amp, buy a well-proven classic like Dynaco, for example, or a brand / model that is sensible and popular in the country you live in.:)

By the way, I think tube amps are best suited for tube amp DIY people, who like to keep on tinkering.:)
 
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Koeitje

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What a dangerous pile of e-waste.
 

Blumlein 88

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What the man in question thinks about it:


Edit:
As I said, as others have pointed out in this thread. If you are going to have a tube amp, buy a well-proven classic like Dynaco, for example, or a brand / model that is sensible and popular in the country you live in.:)

By the way, I think tube amps are best suited for tube amp DIY people, who like to keep on tinkering.:)
I wonder if it hears the buyer complain, "this is a piece of under-powered crap, what a con" and adjusts the sound to convince you otherwise.

I guess Amir needs to retest with a loudspeaker and see how performance changes in different size rooms. 75 watts tube power and double that into a loudspeaker. Sounds like Bob's mental feedback loop has been redesigned. I guess age gets to the best of us, and now Bob's mind is going.
 

diddley

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Oh, no. Spending all day cleaning, sucking up water, moving fans around, etc. The source of water coming in seems to have been taken care of which is good. We will see if it holds when the rain returns on Tuesday.
I hope it stays away, thanks for the review!
 

DanielT

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I wonder if it hears the buyer complain, "this is a piece of under-powered crap, what a con" and adjusts the sound to convince you otherwise.

I guess Amir needs to retest with a loudspeaker and see how performance changes in different size rooms. 75 watts tube power and double that into a loudspeaker. Sounds like Bob's mental feedback loop has been redesigned. I guess age gets to the best of us, and now Bob's mind is going.
Well, if that were the case then it's sad. May be the lack of $ which is a driving force? Nevermind, I hope he is in good health and vigor for his age.
It does not say on Wikipedia how old he is. Maybe he turned 80? What do I know.

 

DHT 845

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Oh man. Good SE Triode amps have 2nd harmonic like -50dB and with lower like -60, -70dB higher harmonics. This PP Carver amplifier measures bad.
 
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