Carver Raven 350 Review (Tube Amp)

[DonH56]

Perfect for tube rolling! Just listen for the subtle differences that only the most discerning golden ear can pick up.

Be sure to change just one tube at a time, or at most a matched pair, to hear any subtle changes that arise.

 

[DonR]

Be sure to change just one tube at a time, or at most a matched pair, to hear any subtle changes that arise.

The subtleness is just sublime, night and day subtleness.

 

[welsh]

Well I'm a guitarist, and always on the lookout for the best 'dirty' tube sound.

I tend to prefer a valve amp with a great ‘clean’ sound and lots of headroom (most big Fenders fit the bill) and get the dirt from pedals. All the legendary drive pedals are solid-state.

 

[welsh]

IP law actually would be engaged there - Carver wouldn't be able to use the name of the reference amp in the model number, and would have to be very careful about the way he used the name in advertising materials, or he could run afoul of trademark laws. Easier to just be cagey.

I seem to remember that Stereophile didn’t identify the ‘perfectionist’ reference amp used in the Carver Challenge. Presumably so as not to annoy a valued advertiser…

 

[welsh]

It's a tube amp. It's supposed to sound different. It's supposed to look different. Take away either, and there's no point to it.

Back in the day, tube amplifiers tried to minimise noise and distortions, and a few managed to achieve audible transparency, albeit at some high cost, especially in the quality of the output transformers. SS amps made all of that detailed circuit design unnecessary, so the only way tube amps would still sell is to sound audibly different, i.e. higher distortion, higher output impedance (which changed the frequency response of the loudspeakers ) and steam-punk looks which appeals to those so inclined.

There's zero reason to buy a new tube amp just for HiFi.

S.

It’s worth remembering that at the peak of valve amplifier technology, no ‘hi fi’ designer would contemplate using single-ended triode designs. They were fit only for jukeboxes and cheap radiograms. Now SET amps are the holy grail for rich old people who can’t hear above 10KHZ.

 

[welsh]

Not necessarily. I mean among tubes of the same type. One 12AX7 sounds the same as another in the frequency response domain.

EL84s definitely sound different than 6V6s to me, for example. But it is difficult to create a valid double blind listening test or null test, because required differences in the output circuits can sound different. And if the circuits are not optimized for each tube, one tube will have its gain structure and/or output impedance compromised at the very least.

If I still had all the stuff to do it, I would quickly build a simple class A, single-ended amplifier with both octal and noval power tube sockets and attempt a null test. Imagine what a successful null test would do to the tube sniffing musicians out there?

(I still love my tube amps, but I have also embraced digital modeling and solid state power amps.)

I have lots of valve guitar amps (I prefer 6V6 and 6L6 designs) but recently a solid-state Boss Nextone Special is getting played most. It surprised me.

 

[Blumlein 88]

I seem to remember that Stereophile didn’t identify the ‘perfectionist’ reference amp used in the Carver Challenge. Presumably so as not to annoy a valued advertiser…

At some point they did. Conrad-Johnson Premier either 4 or 5. I also think at the time they only took ads from audio dealers not from manufacturers.

 

[welsh]

At some point they did. Conrad-Johnson Premier either 4 or 5. I also think at the time they only took ads from audio dealers not from manufacturers.

They certainly didn’t identify the ‘perfectionalist’ amplifier at the the time of the ‘challenge’. I’m sure you’re right about the advertising, although it’s weird to imagine an issue of Stereophile without wall-to-wall manufacturer ads! Notably, the team distanced themselves from the Carver Challenge, with JA claiming (as I remember) that LONG TIME listening revealed the essential differences. As in, more money inevitably buys you superior sound.

 

[Loomynarty]

You mean a frequency response of 20-20kHz within +/- 0.3dB!
This demographic must be blessed with super hearing.

The peak to peak difference between 2khz and ~18khz is more than 1 dB. That is definitely audible unless your hearing is damaged in those regions.

 

[Blumlein 88]

They certainly didn’t identify the ‘perfectionalist’ amplifier at the the time of the ‘challenge’. I’m sure you’re right about the advertising, although it’s weird to imagine an issue of Stereophile without wall-to-wall manufacturer ads! Notably, the team distanced themselves from the Carver Challenge, with JA claiming (as I remember) that LONG TIME listening revealed the essential differences. As in, more money inevitably buys you superior sound.

I don't remember JA distancing those claims, but was a long time ago and maybe he did. The obvious takeaway is that inaccuracy or coloration is what gave the C-J Premier amp its own sound. Not a lack of ability of SS amps. That had to be an experience that would give those involved pause. In the end, they appear to have brushed it off. I myself did testing where you series connect power amps. Load the output with power resistors and tap that with an attenuator so you get unity gain. Then you can switch the amp in and out between the source and the amp connected to speakers. Tube amps switched in were usually easy to hear and made the SS amp on the speakers sound like a tube amp. Not all, but better SS amps were really straight-wire with gain good. You couldn't tell if they were in or out of the circuit.

 

[Xyrium]

That's why metal heads use tube amps, for the distortion!

 

[DonH56]

The Carver Challenge

Is it possible to make a $700 "mainstream-audio" power amplifier sound exactly like a high-priced perfectionist amplifier? Bob Carver, of Carver Corporation, seemed to think he could, so we challenged him to prove it.

www.stereophile.com

Footnote 3: I believe it appropriate nearly a quarter-century later to identify the reference amplifier as a Conrad-Johnson Premier Four.—John Atkinson

 

[Blumlein 88]

The Carver Challenge

Is it possible to make a $700 "mainstream-audio" power amplifier sound exactly like a high-priced perfectionist amplifier? Bob Carver, of Carver Corporation, seemed to think he could, so we challenged him to prove it.

www.stereophile.com

Footnote 3: I believe it appropriate nearly a quarter-century later to identify the reference amplifier as a Conrad-Johnson Premier Four.—John Atkinson

Reading back over the old article it is interesting the Rosenberg letter and its tone. The idea the high end community believe the C-J (or ML-2) were better sounding amplifiers. Since Bob Carver was able to replicate their sound, he should instead use his talents to create a 'better' sounding amp himself. Which he eventually did in the form of the Carver Silver Seven. The point that seems to be missed is the reason his cheap amp could replicate these other sounding amps is they have a colored sound. Not superior in fidelity just superior according to their tastes in coloration. So in essence they were asking Mr. Carver to create his own "superior coloration". An admission that flew over their head that high end was not high fidelity. Some over the years have defended this as being like connoisseurs of sound character. Funny that in that word connoisseurs are the word con and noise.

I believe the Silver Seven taught Mr. Carver that a colored, beautiful, big tube amp with a great story to go with it can be made and sold for a bundle of money. I cannot blame him too much for taking what the market gives. People who buy his amp are I suppose happy enough. His efforts at giving us more accurate amps and SS amps that mimic these colorations just didn't get the same notice. People need to see the glow, the glass and feel the heat to believe they are getting the real deal tube sound.

 

[solderdude]

View attachment 226470
The peak to peak difference between 2khz and ~18khz is more than 1 dB. That is definitely audible unless your hearing is damaged in those regions.

And consider that this is measured with a resistive load. The amp has an output R of a whopping 1.7ohm so when the impedance of the speaker varies there will be even bigger variations in FR than shown here. That, and the potentially audible amounts of distortion is more than likely audible. Which, in the end, is the goal of this amplifier. To sound different from other amplifiers.

 

[Ken Tajalli]

View attachment 226470
The peak to peak difference between 2khz and ~18khz is more than 1 dB. That is definitely audible unless your hearing is damaged in those regions.

I see!
And that @solderdude and @Blumlein 88 have liked it, interesting.
So here is a question to everyone:
- the worst case scenario (on the worst channel) is a slow rise to 0.6dB at 10kHz to about 1.2dB at 18kHz. Regardless of other failings of this amp, what demographic can even detect such a HF rise? Or benefit from it, to the point of buying it? (that was the point, if I recall)
I still say a demographic with very very good hearing! don't believe me? dial a 1.2dB parametric equaliser setting at 18Khz (Q possibly 0.2), and test it for yourself.
I am not saying it is beyond audibility! we are talking demographic of people with good or poor hearing.

This amp has multiple serious flaws! this minor, zoomed in FR discrepancy is neither here nor there.
It's like having a go at Hitler, because he was short!

 

[solderdude]

Your question is not very relevant as the measurement is made using a resitive load.
With a 1.7ohm output R and varying speaker loads the tonal changes made by those aspects are larger.

And yes, 18kHz is only interesting for young audiophiles. + 0.6dB at 10kHz is detectable, certainly when the lift is wide and one can compare directly.
Again this is with a resistive load which the vast majority of speakers is not.

This amp is purpose designed to sound different and measurements (specs as Amir did not measure Rout) say there is plenty of reason Rob (or whoever designed it) did a good job doing that. Whether I, ASR members or owners like those changes is another thing and is very speaker dependent as well.

Just put a 1.8ohm 5W resistor in series with your speaker to find out. In the case of this amp (with the as 'room sensing BS' disguised dynamic output R increasing circuit) the 1.8 ohm may even be too small.

 

[Ken Tajalli]

Your question is not very relevant as the measurement is made using a resitive load.
With a 1.7ohm output R and varying speaker loads the tonal changes made by those aspects are larger.

And yes, 18kHz is only interesting for young audiophiles. + 0.6dB at 10kHz is detectable, certainly when the lift is wide and one can compare directly.
Again this is with a resistive load which the vast majority of speakers is not.

This amp is purpose designed to sound different and measurements (specs as Amir did not measure Rout) say there is plenty of reason Rob (or whoever designed it) did a good job doing that. Whether I, ASR members or owners like those changes is another thing and is very speaker dependent as well.

Just put a 1.8ohm 5W resistor in series with your speaker to find out. In the case of this amp (with the as 'room sensing BS' disguised dynamic output R increasing circuit) the 1.8 ohm may even be too small.

You missed the bit about " Regardless of other failings" , "demographic" and "this amp has multiple flaws" .
The original post was that a certain demographic would buy this amp because it has a rising HF response that matches their hearing loss.
I begged to differ!
I didn't ask if it was "detectable" by golden young ears, did I?
I asked what demographic can hear and benefit from such an FR response?!
I know about the high output impedance, so if the speaker should have a falling impedance at high frequencies (wait for it...) it would correct the amp!
if it is a rising impedance, then it wouldn't. In either case, that was not the question.

 

[Blumlein 88]

You missed the bit about " Regardless of other failings" , "demographic" and "this amp has multiple flaws" .
The original message was that a certain demographic would buy this amp because it has a rising HF response that matches their hearing loss.
I begged to differ!
I didn't ask if it was "detectable" by golden young ears, did I?
I asked what demographic can hear and benefit from such an FR response?!
I know about the high output impedance, so if the speaker should have a falling impedance at high frequencies (wait for it...) it would correct the amp!
if it is a rising impedance, then it wouldn't. In either case, that was not the question.

Your question is impossible to answer. Will this amp with that slow wide rise sound slightly different than a flat amp? Yes. Who likes that? I don't know, and there are many more things beyond just that going on as you said. I haven't said this is significant to fix anyone's hearing loss. So don't know what you are trying to pin down.

 

[SIY]

Your question is impossible to answer. Will this amp with that slow wide rise sound slightly different than a flat amp? Yes. Who likes that? I don't know, and there are many more things beyond just that going on as you said. I haven't said this is significant to fix anyone's hearing loss. So don't know what you are trying to pin down.

The sound differences will potentially be marginally detectable in a direct, rapid-switching comparison. But on it's own? Dubious.

What sells this amp is appearance and story, the sonics are far more likely either an afterthought or not really given any thought. Trying to grasp at 1 dB errors or mediocre distortion performance as some are doing misses the point of the product.

 

[fpitas]

Chances are, the only thing this amp competently corrects is Carver's bottom line.