I went up to see Bob Carver yesterday and listen to the 350’s. After extended listening (the 350’s attached to his ALS speakers) I ended up purchasing a set of the Crimson 350 amplifiers. Bob and Jordan were both very gracious with their time and open and honest with the questions I asked. The listening included A/B testing with the amplifier I am replacing.
Jordan is very knowledgeable about the products and actively involved with Bob in the development of new products, he has obviously spent a large amount of time with Bob learning what he has done and how he has done it. Jordan was able to answer 90% of the questions I asked as well as help me understand the things I was hearing.
Bob offered to sign the amplifiers and I elected to have him personalize the signature. I understand the personalization negatively impacts the value of the amplifiers, but it makes them more valuable to me.
This is the first tube amplifier I have owned and look forward to learning and experimenting with it. I hope I have the opportunity to go and talk to Bob and Jordan again after I have a few months under my belt with the amplifiers. |
Yes, brought them home with me yesterday. Have you received yours? |
@ozzy
I sent an email to Jordan asking about the volume control and he replied that it is on the input stage. I believe this would mean it impacts both gain and volume.
Erich |
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. |
@ozzy
Are the Atma-Sphere amps entirely quite (put your ear right up next to the tweeter on the driven speaker and see if you can hear any hiss)? The gain on the Carver 350 is 30db while the gain on the M-60 is 20db. Do you hear the hiss if you set the carver volume knob to 2/3 (not sure if this knob is volume (output stage) or gain (input stage))?
I am no expert but did just spend two weeks researching and troubleshooting a hiss/buzz issue in the amp the Carvers are replacing and from everything I read if you remove the inputs (in many cases the recommendation was to short the inputs) and noise goes away it is almost certainly not an issue with the amplifiers. The trick then is to find the offending electronics. I didn't know this up front and ended up spending hours of trying different things before finally just isolating the amplifier entirely on a single outlet circuit with all the other breakers in the house turned off and the inputs on the amp shorted only to get the same buzz.
Since you have already determined unplugging the pre-amp stops the hum, maybe start by eliminating the pre-amp and driving the carvers from your sources one at a time and see if one has a buzz while the others don't.
Erich |
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. |
@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. |
@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? |
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? |
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 |
@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 |
@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.
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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. |
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? |
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.) |
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? |
Thank you Ozzy, have a pair on the way. Also have a DEQX on the way. |
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. |
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. |
If by mastered you mean have it hooked up, then yes I have mastered the DEQX. |
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. |
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. |
A 6.3amp and 1amp both in fast blow? |
Did you try the different orientations for the fuse? SR states it is directional, but both fuses in the Carver amp are AC (verified with Jordan), so orientation of the fuse isn't necessarily "easy". |
Ozzy,
Where do you have the jumpers set? 4 on the output and 2-3 on the input (listed as default)?
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Thanks ozzy,
I have my SoundScape 8s now and the highs are still a little harsh. Was contemplating whether to drop the gain before I begin calibrating. I think I will calibrate and then see where I am at as I do not get any sound out of the speakers when there is no source playing.
Erich |
