Carver Raven 350 Amps


Has anyone heard these amps?
They supposedly can produce 350 watts per channel which in my opinion is remarkable for a tube amp. I have the Atma-Sphere M-60’s 3.3 and I love their tube sound.

But I am curious, Bob has made some very interesting products through the years.

ozzy
128x128ozzy
erichgs,

Thanks for your reply. I would not describe the hiss as hum, but it is quite noticeable sitting even 15 feet away from the speakers with no music playing.
The Atma-Sphere are pretty much quiet compared to the Carvers.

I just tried reducing the Carver volume knob and it does reduce the hiss but it probably also reduces the overall volume too, hopefully not too much.

ozzy
10db of gain is a fairly large difference and I would think could easily account for hearing the noise coming from the input on the Carvers while not on your other amps.  LIke I mentioned before, if you pull the inputs and no longer hear the noise it is almost certainly not the amp from everything I have read.
On my Carvers I get a small amount of hum even with the input disconnected.  It goes away when I short the inputs and even when there I have to be within ~3 inches of the speaker to hear it.  This is with the amplifier volume knob at full and is the same on both amplifiers.  I also get some power supply hum from the amplifiers themselves but have to be very close to hear that as well.

erichgs, how are you doing with that hum, i was thinking of buying the raven 350, how do they sound how is the soundstage,  deep ,

i have a cary slp-05 preamp, would this be a good combo,

@smokenjo

The hum on my Carvers is what I would consider acceptable and not caused by the amplifiers themselves.

As for how they sound, they are a little bright on the speakers I have now. I am currently using the Salk HT-MTM’s I purchased 6 years ago. Though very clean and decent with music they are intended for home theater use. I have Salk SoundScape 8’s being built right now. I have heard the SoundScape 8’s with Carver 305’s and really liked the sound. According to Bob, the 350’s are very similar sonically to the 305’s.

Additionally, I listened to the amplifiers that are in my house for several hours and on several different speakers when I was up visiting Bob and never experienced the brightness. This was computer->DAC->amps->Speakers (in the case of the ALS speakers there is an adjustable crossover as well.)

At any rate I will reserve review on how they sound until I receive my SoundScape 8’s outside of saying I sat and listened to music for 4 hours last night and enjoyed every minute of it.

Even on my current speakers the soundstage is, to me, amazing. Of course, my experience with other amplifiers in my house is fairly limited but the AVA 600r the carvers replaced does not come close in soundstage. I verified this with A/B testing both at Bob’s place and in my home.

I do not plan on running a seperate pre-amp.  Unless I really hear something I don't like, I plan to go directly from my Benchmark DAC3 to the Carver's.  I am of the thought that I got what I wanted for speakers and amplifiers I should avoid anything else impacting the sound.

I hope this answered your questions. I am still learning a lot on a daily basis.
Erichgs, Dracule 1,

Are you using the volume setting on the Carver at full level?
I can reduce the hiss if I reduce the Carver volume knob to the 12:00-1:00 position, but, by doing that am I reducing the Carver 350 watts per channel capability?

ozzy
I have been using them at full.  Since the knob is impacting both volume and gain, I am not sure how much it impacts the ability to use the full capability of the amplifier.  You will, obviously, have to turn your source up further to get the same output.

You haven't been able to determine which of your sources (or if the preamp itself) is causing the noise?
erichgs,  can you guess what speakers i have  SALK SOUNDSCAPE  8, with upgrade on the xovers, mundoff , the amp I have now is AVA 600R FET
@smokenjo 

Every speaker I listened to while visiting Bob Carver, the Carver 350 blew away the 600R for soundstage.  On one of the speakers I thought the 600R had a better sound in the highs, but over all I preferred the sound from the Carver amp on every speaker I listened on (even the one I thought the 600R had better highs on.)

What finish do you have on your SoundScapes?
erichgs,

If I connect the output from my Direct Stream Dac directly to the Carver amps there is very little hiss.
But if I connect the Direct Stream output to the input of the BSG QOL or to my DEQX Premate preamp and then to the Carver amps I get the hiss. Either piece of equipment will cause the hiss. 

Bob Carver suggests reducing significantly (50% from full level) the Carver volume control and just turn up the level on the DEQX Preamp. To do this I would be playing the DEQX Preamp at its 85-95% top settings. I'm not sure I like that.

When my Atma-Sphere Amps are used instead of the Carvers there is complete silence.

I don't know what more to do. 

All of my equipment has true balanced connections and quality balanced interconnects are used. The Carver even though it has a XLR input it is still just a single ended connection. I think if the Carver amps had a true balanced input there would be no problem.

ozzy
@ozzy 

Have you tried the RCA inputs?  Maybe it is possible that your balance out to single ended in is causing a ground loop or some kind of feedback issue (not sure what Carver is doing with the unused pin.)  I can try the XLR inputs on mine and see what happens.  It is single ended and I have RCA everywhere else, so I didn't see the point in using it.

Erich
erichgs,

No need to. Bob says the RCA and XLR are wired together as a single ended input. The XLR is there for convenience not for a true balanced connection. So either rca or xlr should perform the same.

ozzy
So switched to the XLR inputs on mine and it actually reduced my hum (which manifests as a hiss from the tweeter.)  Now have to be inside of an inch to hear it in a fairly quiet room.

Again, I am just going from the benchmark dac3 directly to the amp and can't find anything on whether the XLR outputs on the DAC3 are actually balanced.

Erich
erichgs, and others.

Well I finally found the reason for the hiss.

I was using the XLR output of the DEQX preamp with a XLR cable into the Carver XLR input.

Since the Carver does not have a true balanced input (but my DEQX preamp does have a true balanced output) you have to use the rca (single ended) output from the preamp into the Carver inputs.

Confusing but it makes sense. Single ended output to single ended input. Simple as that.

That being said the Carver amp really should not have a xlr input connection without it being a true balanced connection. What would be the use?

Anyway, I now have a DEAD silent connection, no hiss or hum etc.

ozzy

ERICHGS, my veneer is KINGSWOOD, if you go on the SALK site

 go to the gallery , model-SS8, VENEER-KINGWOD, THOSE ARE MY SEAKERS, when JIM sent me a photo of the veneer I had ask him,  try putting a orange dye to bring out the grain, he did they look

GREAT they have a grain that looks like the eyes of a OWL


@ozzy 

Good to hear you got it sorted out.  Bob was saying he provides the XLR input for people who only have XLR outs.  Similarly, the 4 and 8 ohm outs are also tied together but when he provided a single for those two he got a lot of questions.  The 2 ohm is separate as it internal requirements differ. 

Like I said, oddly enough connecting via XML makes mine quieter.  Probably, the RCA out on the DAC is generating the little bit of noise.

So yours are dead quiet now?  Even if you put your ear up to the tweeter with nothing playing?

@smokenjo 

I really like those, very nice.  I went with quilted sapele on mine, can't wait to get them.  Also, I have an SS7 center coming in the same finish.  At 23% complete right now so likely still be a few months out.

I went searching for you on audiocircle last night and found your post (assuming it is you) in the thread with the guy who is using the 305s with his SS10s and came from an AVA 600R.  Looks like multiple people are enjoying the pairing of these amplifiers with SoundScapes.  This is good to know.


erichgs,

Yes dead quite. If there is any noise I can't hear it. 
BTW, I also placed rca non shorting caps on the rca inputs. Perhaps that's what took it to zero noise.
Everything matters...

Now to experiment with input tubes...

ozzy
The Benchmark DAC3 has jumpers to attenuate the XLR output.  I moved the jumpers from the default position (0db) to the middle setting (-10db) and now I am noise free as well.
erichgs,

I have moved my jumper and output settings on my DEQX premate to its highest output settings and still no hum. 
I can't tell you how satisfying it is to have discovered the source of the hiss. It was amazing that I missed something so obvious for a week.

smokenjo,

They can be purchased from  many places. I bought mine off of EBay from a guy located in Michigan, they are of  very high quality and with fast delivery. Now remember these are caps not shorting plugs. I have used them on all of my unused rca and xlr input/output throughout my system.

ozzy 
The shorting plug shorts the signal to the ground where the cap just covers and protects from the elements.
If you have multiple inputs, depending on how they are wired shorting plugs can be a bad idea.

Ozzy,

I had never looked at the DEQX equipment.  Does it really make that big of a diffrence?  Which DAC implementation do they use?
erichgs,

Some equipment does not work well with the inputs shorted.
I am using the DEQX as an electronic crossover and to blend the subs with my main speakers in the room. And it is quite a complicated piece of equipment that can make a big difference.

ozzy


So I am going to keep the Carvers since they allow me to try other "hard to drive" speakers. Quads, Electrostatics, and Planers are on my list to try.

I must say though my Atma-Sphere M-60 3.3’s are very nice sounding amps that I hope I do not regret selling.

I have an ad on the "Gon’" for their sale right now with over 800 views in 4 days!

ozzy
I am just using the cords that came with the amplifiers.  No issues, so no reason to change.

ozzy,
Been doing some reading on the DEQX products I and am fairly certain I am going to pick one up.  It will be nice to be able to room correct my own setup and it will do a much better job with subwoofer crossover and also allow the subwoofers to be integrated into stereo listening if I choose (which I can't do now.) 
erichgs,

Upgrading the power cords has provided a fairly impressive sonic improvement. Don’t sell this upgrade short.
Another improvement can be made by changing the supplied 12ax7 input tube to a vintage Telefunken tube.

And believe it or not I found upgrading the 1A fuse to a SR Red was also significant. Later on I’m going to replace the red for a blue fuse. But only after I’m confident the tubes have settled down and will no longer pop the fuse.

The DEQX has quite the learning curve, but once mastered it can provide great integration between subs, mains and the room.

ozzy
So only change the 12ax7 and not the 12at7?  Completely new to tube amplifiers and haven't even started researching tube rolling yet.  Anything I should be looking for when purchasing vintage Telefunken (stick with NOS, year, etc)?  Any place recommended for purchase?
erichgs,

Yes, according to Bob Carver the 12ax7 is the tube most sensitive to upgrades. Stick with Telefunken tubes that were made in West Germany vintage 1960's. Decent condition ones cost about $120-$150 a pair.
EBay is probably the best place to find a selection.

ozzy
Right now Salk HT-MTM, but preparing for Salk SoundScape 8s that are being built right now.
@smokenjo 

Really interested in hearing your impressions of the 350's with your SS8's

@ozzy 

Did you get your DEQX, was it new?  If so, how was it packaged?  I received mine tonight and it looked repackaged and had several small scratches in the case.  It was also packaged in a plane white box.

I emailed  bob carver asking about tubes, I have a matching  pair of

MULLARD 12AT7 [CV4024]   JORDON , emailed me back telling

me to try them, they should make a difference, hope for the better !!!!!

erichgs,

I also purchased the DEQX used but it did come in a DEQX box.

smokenjo,

I agree give them a try. The only other tubes that I have tried is the Telefunken and the ones that came with the amp.

ozzy
I just installed Telefunken 12AT7 tubes and they also complement the Telefunken 12AX7 with the Carvers.

ozzy
That is good to hear as I also have a set of Telefunken 12AT7 tubes on the way (purchased tuesday after some reading.)

Erich
Ozzy,

Just an FYI, the balanced outs on my DEQX are very noisy on the Carver 350s as well. RCA dead silent.  On the Benchmark DAC3, the balanced outs are quieter than the RCA outs, but not quite as quiet as the RCA on the DEQX. 
erichgs,

Well its nice to know that we both hear the same noise (hiss).
Bob Carver doesn’t really believe me. He thinks there is something wrong with the DEQX.
Oh well, at least with using the RCA outs on the DEQX to the Carver it is dead quite.

BTW, have you mastered the DEQX?

ozzy
Swapped the Telefunken ECC801s pair in for the stock 12AT7s.  The improvement is larger than when I swapped the Telefunken ECC83 pair in for the stock 12AX7s.  Really happy with the sound improvements from these changes.
erichgs,

There are a lot of settings in the DEQX and it can be difficult to master. The instructions make you jump back and forth. I was just wonderin’ if you have it figured out yet. I have found that my main DIY speakers sound best without any DEQX adjustments but the sub crossover, delay and mixing with the main is valuable.

On the tubes, is it the sum of both of the Telefunken tubes or is one slot better than the other?

ozzy
I haven't tried swapping the stock 12AX7s back in, but I would have to imagine it is the sum of both.  Also, the improvement for the ECC801s was very noticeable in the highs which was too bright before.   The ECC801s did a lot more to mellow that than the ECC83 did.
I am just using the cords that came with the amplifiers. No issues, so no reason to change
I bet replacing stock PC will yield bigger improvement over tube rolling.

FYI, there are 2 types of Telefunken 12XXX tubes, ribbed and smooth plates.  ribbed plate is more neutral with higher resolution.  I always prefer ribbed plates.