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Carver Raven 350 Review (Tube Amp)

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 260 82.8%
  • 2. Not terrible (postman panther)

    Votes: 29 9.2%
  • 3. Fine (happy panther)

    Votes: 15 4.8%
  • 4. Great (golfing panther)

    Votes: 10 3.2%

  • Total voters
    314

amirm

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This is a review and detailed measurements of the Carver Raven 350 tube monoblock amplifier. It is on kind loan from a member and (I think) costs US $4,750.
Carver Raven Monoblock 350 watts Amplifier Tube Review.jpg


The 350 is not a bad looking amp. It has the same "orange peel" paint job of the previous Carver 275 amplifier I reviewed. At 42 pounds, the unit is pretty heavy. With all the weight in the back, the front handle is kind of useless when it comes to lifting it.
Carver Raven Monoblock 350 watts Amplifier XLR RCA Tube Review.jpg

There is an XLR input but I believe it is for convenience and performs the same as RCA. I measured the DC resistance of the 4 and 8 ohm terminals (after the measurements) and realized they are both the same! Here I was switching back and forth between them. :( Anyway, measured DC resistance is 0.47 ohm. The 1-2 ohm tap has a lower DC resistance of about 0.3 ohm.

Unlike the 275 amplifier, the fuses did not blow and the amp survived my sweep tests. Bias is to be set at "80" on the front dial and that was the case when I powered on the unit.

There is a gain control but you are advised to set it to max which is what I did for testing.

There is a flip switch in the front which changes the amount of feedback. I tested the amp in both settings.

Here are the specs:
Carver Monoblock Tube Spec 350.png


Carver 350 Measurements
Let's start with high-feedback performance using XLR input:
Carver Raven Monoblock 350 watts Amplifier High Feedback Measurements.png

There is copious amount of distortion causing SINAD to be dominated by it. At 44.1, it ranks as the second worst amplifier ever tested:
best tube amplifier review.png

It even performed worse than the Carver 275 which had a SINAD of 46. Switching to lower feedback doesn't make things that much worse:
Carver Raven Monoblock 350 watts Amplifier Low Feedback Measurements.png


Note that gain is reduced and therefore, volume will be different. This makes AB testing tricky. Here is a more detailed FFT showing the small difference between low and high feedback:
Carver Raven Monoblock 350 watts Amplifier FFT Feedback Measurements.png

Notice how distortion is made up of both 2nd and 3rd harmonics so you can't make the argument that it is "2nd harmonic goodness."

As noted, RCA performance is the same as XLR:
Carver Raven Monoblock 350 watts Amplifier RCA High Feedback Measurements.png


Power supply 60 Hz noise in both cases causes severe intermodulation higher up in frequency. No amount of grounding impacted that so it is endemic tot he design.

Noise performance is decent for type of amp it is:

Carver Raven Monoblock 350 watts Amplifier SNR  Measurements.png


Intermodulation distortion rears its ugly head again in multitone test:
Carver Raven Monoblock 350 watts Amplifier Multitone Measurements.png


I don't know how anyone could hear more "detail" with such an amp where so much of the music signal will get lost in the distortion "grass."

Frequency response should be flat but it is not:
Carver Raven Monoblock 350 watts Amplifier Frequency Response Measurements.png

It naturally will have load dependency due to output impedance.

Let's see the power situation as we had serious shortfall in the 275 amp:
Carver Raven Monoblock 350 watts Amplifier Power into 4 ohm Measurements.png


We don't meet the spec there but come closer with 8 ohm:
Carver Raven Monoblock 350 watts Amplifier Power into 8 ohm Measurements.png


Back to 4 ohm, here is our 1% THD (double the company spec) max and burst power:
Carver Raven Monoblock 350 watts Amplifier Max and Peak Power into 4 ohm Measurements.png

We seem to get the same shortfall. There is momentary reservoir though allowing the peak output to shoot way up. This was not always consistent though.

I also tested 2 ohm capability:
Carver Raven Monoblock 350 watts Amplifier Power into 2 ohm Measurements.png


You are still current limited so no more power.

Changing the test frequency gives us the following power curves:
Carver Raven Monoblock 350 watts Amplifier Power into 4 ohm vs frequency Measurements.png


There is some instability at 20 Hz and fairly significant power drop. This points to power supply not having enough capacity as the lower frequency taxes it for longer period. Some drop occurs in every amplifier by the way so it is a matter of how much.

Finally, the amplifier warms up quickly and is pretty stable:
Carver Raven Monoblock 350 watts Amplifier Warm up Measurements.png

Testing occurred after this warm up.

Conclusions
What an upside down the world of audio is. Folks want to pay so much more to get dirtier sound. You want dirty? The Carver 350 gives it to you. Even at 5 watts there is copious amount of harmonic distortion. Power supply mixes with that at such high level that it creates its own spread of distortion. A video must come with these amps that hypnotizes you into thinking you are getting great sound....

I can't recommend the Carver 350 monoblock amplifier.
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DSJR

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Back in the 80's, reviewer/guru Martin Colloms raved about similar US 'high end' valve amps from ARC, Quicksilver, VTL, C-J and so on and made all manner of excuses about measurements not correlating with what he and the listening panel heard. Indeed, it became a thing that all the best measuring amps tested in 1980's 'Choice' books more often than not, did badly in the listening tests, as the lack of added character usually made the sound leaner and with less 'depth' perspective (added compression in the favoured ones?) and most recommended or best buy amps were somewhere in the upper 60's 70's for estimated sinad. In the UK, this reviewer became 'important' as he had interests all over as consultant, designer and so on and people took notice of his reviews.

I'd suggest this Carver box is exactly how it's supposed to be, giving a wonderful sonic character.

Did you 'listen to it' Amir ('cos 'we' don't listen to test tones, do we?). Sorry for that, but that's going to be the audiophile response to this review... Would be great if this distortion 'grass' can definitely be heard as against a pile of cheaper alternatives that don't have it... ;)
 

JSmith

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I'd suggest this Carver box is exactly how it's supposed to be, giving a wonderful sonic character.
I'm sure your correct and it's meant to be this way... but why would one want a baked in sonic character that can never be altered?

If people are looking to play with distortion and noise levels, give this a whirl;
Much cheaper than this amp... or even a free one;


JSmith
 

restorer-john

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Last edited:

GXAlan

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Does anyone have any JAN tubes that they can send to Amir? You would imagine that the old tubes intended for use in test equipment will be better than todays modern tubes intended only for “audiophiles”

The lack of the ground is a deal breaker even though I do have a tube amp I enjoy listening too, even though it’s not transparent.
 

JeremyFife

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Genuinely don't understand this. Obviously it measures terribly ... is it meant to be like this, is it a design decision? Surely for $5k there is some competence and intent in the design and build ... baffled.

Is this analogous to cars that look cool and have massive engines that make an amazing noise but handle like sh#t (and no-one cares because they want the look and noise)?
 

fordiebianco

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Blimey. I wonder how the Line Magnetics compare with this brand.
 
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abdo123

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Gotta love that tube sound. So musical. You need to use the special listening aid with this though
View attachment 225122
Ironically this will get significantly louder than any Topping amplifier.
It would be foolish to dismiss this as a product from a designer that isn't competent. Bob Carver was the designer who took down Sterophile with his challenge mentioned in the link below.


Would anyone notice the fact that this has measurably poor performace in a DBT?

Yeah it will sound different it’s already 1% THD full spectrum.
 

GXAlan

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Genuinely don't understand this. Obviously it measures terribly ... is it meant to be like this, is it a design decision?

Hard to say. The tubes themselves make a big difference in sound quality. Companies like GE and Raytheon used to make tubes for industrial applications like oscilloscopes and you wanted maximum quality. Nowadays, nearly all of the tubes are made in Russia and China

I had a McIntosh Mc2102 (sold) and currently have an SFS-80 running Milspec (JAN = Joint Army Navy) tubes. They aren’t state of the art but with those tubes it’s definitely on par with my JBL SA600 to my ears. I’d be shocked if the SA600 did worse than these :). @amirm

You can see Stereophile’s measurements of the MC275 here

Bascom King measured the SFS-40 here which ran 7 dB of negative feedback. He is the designer of the BHK PS Audio amps as well.

 
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