Carver Raven 350 Review (Tube Amp)

[Nango]

When the musicians do not distort enough while playing this unit can make it so the guitar riffs sound way more authentic. Hard rock and similar genres will sound like celestial on these amps.

 

[Mart68]

I made the plunge into tubes in the mid-late 80s in a smaller way, buying a CJ MV 50 to power my LS3/5as at the time. For a while I enjoyed it, but I began to notice it overlaid everything with a kind of honey like glaze while blurring details. In short, it made everything sound homogenized and sweeter than live which to me is the very definition of a colored component.

I used a fairly cheap tube pre-amp for a couple of years, it made everything sound like it was recorded in the same studio in 1969. I eventually got tired of that.

Some aspects of the sound were interesting. For example electric guitars sounded like they were plugged directly into the loudspeaker. I can see the appeal at least short term. Also can see how some people assume that a colouration like that is actually the 'real' sound of the recording coming through due to the wonderful transparency inherent to tubes that solid state simply can't manage.

 

[Mulder]

Tubes are a "limitation". Most tubes are single transistor, anode-cathode stuff. Kinda hard to build advanced circuits with feedback and correction based on tubes, solid state allows you to print a zillion transistors and advanced logic and what not. Tubes also operate at much higher voltages than transistors - makes them easier to be a heat and even fire hazard. Tubes' longevity is also so-so (think incandescent bulbs and how happy many of your are with LED bulbs), hence plan on keeping spares... And tubes also have quite significant manufacturing inconsistencies (manual stuff going on, really), making matching key... which often manifests itself in channel measurement inconsistencies. And your need to keep spares that match.

I am not saying the limitation is an unsolvable problem for enjoyable audio experiences. There have been some great tube designs, but engineers with that core expertise have long retired. Personally I don't trust tube designs these days, it's build on the "vinyl and tubes are a match made in heaven" mystique without the infrastructure to back it up: tube manufacturing is a niche, tube design practices weren't even taught in engineering school when I studied in the 80s, so who really has access to know how or top manufacturing?

When people bring up tube designs that measure "well" (which is always merely OKish at best), it's some vintage gear that probably doubles as a fire hazzard in your home.

That said - I have a friend with a tube amp that I thoroughly enjoy listening to with certain types of music. :-D

Yes, it is a niche, but the main market is probably not HiFi. It is the market for guitar amplification. Most electric guitar players still prefer tube-amps. I think HiFi tube amps are possible only because the need for tubes in the music industry. It will be interesting to se what happens now to the supply because of the war in Ukraine. Russian made tubes will not be exported anymore i guess.

 

[Mulder]

This is exactly where this forum has issues. Everyone who has heard both or upgraded their ST to VTA knows the VTA sounds better. Its much faster, cleaner, and has better bass response. However, on the measurements it fails. There has got to be some sort of pulling the subjective side more heavily into this, with blind A/B work.

I am not saying the data is wrong, but there is clearly much more to the picture. The VTA amp sounds significantly better than many of these amps that rank higher on the list. IMO, there needs to be some effort in distinguishing what are (and why) the subjective elements people prefer.

As I understand it, the VTA clone is for DIY? Is it not possible that the individual variations are quite large? Both in terms of home-built VTAs and old vintage Dynacos?

 

[Deleted member 50971]

This is exactly where this forum has issues. Everyone who has heard both or upgraded their ST to VTA knows the VTA sounds better. Its much faster, cleaner, and has better bass response. However, on the measurements it fails. There has got to be some sort of pulling the subjective side more heavily into this, with blind A/B work.

I am not saying the data is wrong, but there is clearly much more to the picture. The VTA amp sounds significantly better than many of these amps that rank higher on the list. IMO, there needs to be some effort in distinguishing what are (and why) the subjective elements people prefer.

Hi, i’m a newbie on ASR, although I’ve read hundreds of threads on here, and follow Amir‘s YouTube channel. I’m not able to fully read the graphs done in the testing, although I’m better than I used to be, and learning. This being said I just introduced a new DAC into my set up yesterday, highly touted on ASR as being transparent, and wow did it sound good. I actually thought it sounded better than my other transparently measuring DAC’s and over the weekend I’m going to dispel that notion, and put them all on a transparent XLR switcher.

I don’t have the Dynaco amps, but I do have one of Roy Mottrams SP-14 preamps, and this is in my opinion a very good sounding unit. I think he’s done a good job of bringing tubes into the 21st-century, without coloring the sound. Bob Latino also takes Roys (I understand Bob is retired, so he did take) preamps and supposedly transforms them into a super preamp.

Here’s the problem, there’s absolutely no information that I could find about testing, and just because someone gets the idea in their head that it’s an improvement, doesn’t mean it’s going to be.

New companies are re-designing an old topology and supposedly making it better. Here’s the problem for us audio science based audiophiles… where’s the proof?
Except for a couple of places online, I can’t see very many measurements for tube gear, and the ones I do see you like stereophile basically say unless you spend x amount of dollars you’re not going to get the best tube amp (measuring) available. Even 3/4 of the solid state gear manufacturers don’t post useful specs for the most part. So everybody’s taking their word for it, they’re under the assumption that because it’s filled with the best electronics it has to be good. Everybody else says it sounds good so it must.

This is where ASR is invaluable in my opinion, because it’s blown up the only “high priced audio gear is worthy mentality”

I’m not singling out you, and I’ll even put myself in this category, or statement that I’m going to make. In a proper level matched double blind test can you or I pick Bob Latinos amplifier over a stock dynaco 70 running within spec? Maybe or maybe not, but it’s not easy to do a proper level matched double blind tube gear test, and the best I’ve been able to come up with in my own setting is a comparison on an XRL switcher (I had my SP-14 built with XLR in and out) between the tube preamp and a SS preamp. I’ll tell you even though it was sighted they were very similar, and I seriously doubt I could pick one over the other in a blind test. but isn’t that the way it should be, and shouldn’t tube gear be transparent also?

Another car analogy… I have a Toyota tundra pickup that I use, 121,000 miles it’s going on 18 years old, and the truck is just amazing. Every time I think about trading it in I’m like do I really want to spend $40,000 on a new tundra to replace it. Sure I could make it better stronger faster but am I going to make it any better in the end, or am I just going to bring it out of the specifications of those that worked a long time making it the way it was meant to be. Just my two cents.

 

[DSJR]

It

Hi, thanks for the background. Very interesting, especially today when state of the art amplifiers are affordable and distortion generators costs many thousands of €/$…

may I ask you two questions?
1) are you suggesting that’s better to take the BLU pill = “wonderful sonic character” of the fake sound instead of the RED pill and get the “leaner and less depth” transparent sound as the artist intended to be?

2)why “the audiophile“ must be always the guy of “do you listen to it” ?
I do my best to behave as an audiophile, looking for transparency from recording studio to my ears… and honestly I really don’t have time to waste to listen to poor and fake sound such the higly distorted one produced by low SINAD amplifiers, life is too short… who do really have?

looking forward
my best
L.

It depends how far 'down the path' you are really. You often start as I did, working up to a high end sound rig which makes everything the same, as all the added 'character' basically overwhelms differences in recordings and production with a wonderful golden 'halo' around every music performance you play. In the end and in my case, I upped my exposure to live music, especially small scale 'pub' jazz (not 'my' genre but the company was good and I was able to hear brass and drums close up) and I had something of an epiphany moment. That led me to ATC but of course now, there are many other top monitor brands at lower prices which I'm sure would do the same (or better) as ATC did for me back then. My 'HiFi Journey' stopped once I went this way and it was marriage a few years later and squeezing two small homes together into one which brought my audio nirvana crashing down, never to recover to that level if truth be told...

So, I'd kind of say '2' in your case, but using as much mixed live unamplified sound as a reference, accepting you can't totally recreate the dynamics unless you have a pair of very large active monitors from our favourite brands here 12" or 15" main drivers a must really depending on listening room size You then start to realise you don't have to spend a fortune on the gear to get a great involving but basically truthful if smaller facsimile of the real sound.

 

[Waxx]

I could think this tread would be full of tube amp bashing. It's not for you, i know... Tube amps have higher distortion and a coloured sound, that we know even without ASR tests. That is why a lot (not all) buy tube amps. They like the colour. If you don't, don't buy those.

And it seems that Amir gets a lot of bad tube amp models. Carver is not really known to build good tube amps in the tube amp world. It would be better to get the more popular brands, like Yaqin, Line Magnetic, Prima Luna, ASR, VTL, Leben, Manley and McIntosh. Those are rated high, and would be a better subject to the "Amir test". This one i knew before i red the article that it would be very bad, even for a tube amp...

 

[pma]

@amirm ... a strange question. Seeing that there are no listening impressions and this amp can actually change the sound (probably not for the better ) is it possible to record some music played through this amp (into a dummy load) and the original and post that. A short excerpt may be all that is required.
Not many people get the chance to listen to such 'amplifier effect devices' and could be interested to hear what it does to the sound and or AB it.

Please feel free to try almost the same test you are asking for that I already posted at ASR in December 2020:

ABX distortion test on a real-world tube preamplifier, about 2.7% THD

After a short rest, I have a new listening test. Now, the original file is tested against the file that was played and recorded through the real tube preamplifier and of course there was a DAC/ADC path to record the file. The link to test files is...

www.audiosciencereview.com

 

[Waxx]

Btw, if you know tube specs a bit, then you could know that 3 pairs of KT120 giving 350W is really driving the tubes very hard to maximum, and then the distortion is always very high. If the amp would be a lot more conservative (like using 5 pairs of KT120's for the same wattage, so less hard driven) the sound would be a lot cleaner. This hard driving the output tubes also means they are not going to last long.

 

[milosz]

What was the output source impedance of this amp, Amirm? I did not see it in your tests. This is an important spec for tube amps as it will determine the magnitude of Ohms-law frequency response variations when driving speakers due to their impedance which changes as a function of frequency.

I suspect that this amp would have a rather high output source impedance, which is part of what creates that "tube sound" that some love so well.

 

[AudioSceptic]

Should be about the same. All these high power pentode tube amps were meant to be distortion generators so as to give them mellow character while being able to power most speaker loads. This is the classic kind of amp TAS reviewers (esp HP) went gaga over. The names roll off the tongue: VTL, CJ, Audio Research, Jadis, Line Magnetics, Mesa Boogie, Cary, Carver, Manley, and Convergent Audio Technology. Anything putting out over 200 WPC into 8 ohms and costing less than $10k was considered a bargain. I sincerely doubt even one of them could attain a SINAD over 60 which is something even my $160 Behringer A500 can handily surpass.

I made the plunge into tubes in the mid-late 80s in a smaller way, buying a CJ MV 50 to power my LS3/5as at the time. For a while I enjoyed it, but I began to notice it overlaid everything with a kind of honey like glaze while blurring details. In short, it made everything sound homogenized and sweeter than live which to me is the very definition of a colored component. I found my Hafler DH 200 was actually far more transparent. So eventually I traded in the CJ and haven't looked back since. Generally, I think, people who want their music to sound a certain way (and I literally mean all their music) might find a tube amp appealing. So if you're the kind of guy who wants Johnny Rotten to sound like Tony Bennett, Keith Richards to sound like Chet Atkins, Stravinsky to sound like Brahms, and Wendy O Williams to sound like Linda Ronstadt, then tubes may just be for you.

I doubt that any amp could do that, but thanks for the amusing thought.

 

[solderdude]

Please feel free to try almost the same test you are asking for that I already posted at ASR in December 2020:

ABX distortion test on a real-world tube preamplifier, about 2.7% THD

After a short rest, I have a new listening test. Now, the original file is tested against the file that was played and recorded through the real tube preamplifier and of course there was a DAC/ADC path to record the file. The link to test files is...

www.audiosciencereview.com

Your test amp is a good 15dB 'worse' in 2nd distortion and 20dB 'better' in 3rd though.
4th harmonic is at an almost ? audible -60dB in this amp and good as inaudible -72dB
There is an OP transformer in place and 0.5ohm output R which can interact with speakers which is not entirely the same as a pre-amp.
So the Carver is worse and better at the same time.

Still your file may well be interesting for some readers for sure.

I can understand Amir lacking the time to set it up and making an attenuator (his backlog must be huge).
We seem to have more time and resources available to do such tests and tinkering.
I can set things up with various G1217 designs but would not be the same so never went through the trouble. Besides... people will complain about chosen music pieces anyway.

It would be great to have a standard, highly revealing reference track where there is consensus this is the best track for testing. Not even mentioning playback chains...

 

[solderdude]

What was the output source impedance of this amp, Amirm? I did not see it in your tests. This is an important spec for tube amps as it will determine the magnitude of Ohms-law frequency response variations when driving speakers due to their impedance which changes as a function of frequency.

I suspect that this amp would have a rather high output source impedance, which is part of what creates that "tube sound" that some love so well.

Amir measured the DC resistance (0.47 ohm for high and 0.3 ohm for low tap) but rest assured the output Z will at least be higher than that and frequency dependent.

 

[Shadrach]

It cuts both ways - what you suggest is that one could spend $250 on a Crown amplifier and get indistinguishable sound against this $3500 product in DBT. So yes, this is why DBT is so anathema to audiophiles with more money than sense. I'm very much willing to pay more for the little conveniences and comforts of design, UI, good remote, more I/O options, room correction, tactile controls, energy efficiency, etc. and know that other than room correction, I'm paying for the little luxuries unrelated to "better" sound.

Yup, you've got it. I wouldn't buy this amp, but not because it would sound terrible.

 

[JayGilb]

This is exactly where this forum has issues. Everyone who has heard both or upgraded their ST to VTA knows the VTA sounds better. Its much faster, cleaner, and has better bass response. However, on the measurements it fails. There has got to be some sort of pulling the subjective side more heavily into this, with blind A/B work.

I am not saying the data is wrong, but there is clearly much more to the picture. The VTA amp sounds significantly better than many of these amps that rank higher on the list. IMO, there needs to be some effort in distinguishing what are (and why) the subjective elements people prefer.

That's why it's named Audio Science Review and I mentally separate the technical review from the comment section. The forum members can quibble about it how it sounds and the subjective elements people prefer.

 

[Orion76]

So the XLR connectors are NOT actually balanced?

 

[fordiebianco]

IMO this is just another money grab off of Bob Carver's name, and nothing more. The 275 was aimed at the "lower end" of the audiophile market and this unit is aimed at the "higher tier" of folks who have more money to spend on boutique looking products. I'm sure two of these look cool in a doctor's/lawyer's/CEO's audio rack in the recreation room with an expensive pool table and other odds and ends of things to look at and play with.

Not all doctors/lawyers/CEOs are audiophools.

Just saying.

 

[abdo123]

Your test amp is a good 15dB 'worse' in 2nd distortion and 20dB 'better' in 3rd though.
4th harmonic is at an almost ? audible -60dB in this amp and good as inaudible -72dB
There is an OP transformer in place and 0.5ohm output R which can interact with speakers which is not entirely the same as a pre-amp.
So the Carver is worse and better at the same time.

Still your file may well be interesting for some readers for sure.

I can understand Amir lacking the time to set it up and making an attenuator (his backlog must be huge).
We seem to have more time and resources available to do such tests and tinkering.
I can set things up with various G1217 designs but would not be the same so never went through the trouble. Besides... people will complain about chosen music pieces anyway.

It would be great to have a standard, highly revealing reference track where there is consensus this is the best track for testing. Not even mentioning playback chains...

To be honest it’s nearly impossible to tell distortion with most instruments because they’re so inherently distorted on their own. You need crisp vocals or maybe some loud subbass with a lot of high order harmonics.

 

[Jim Shaw]

Unless you are physically incapable of using a manual transmission (or it is an EV), a stick shift is *always* the right answer.

In 1958. But time travel backward is entirely in your cabeza. If you can time travel, why not back to harness and reins?
You'll find more like-minded there in that analogy.

 

[pma]

To be honest it’s nearly impossible to tell distortion with most instruments because they’re so inherently distorted on their own. You need crisp vocals or maybe some loud subbass with a lot of high order harmonics.

Definitely it is impossible with almost any natural music signal. And do not forget speakers.