C712 back from the Upgrade Company

[David]

I thought I would give an interim report. It is now approaching 400 hours of burn in of the upgraded C712. 200 more and the sound should be completely stable. I let it run without amplification over night and during the day connected to a tuner. Now and then I give it a rest, so it is not quite on 24/7.

The burn in period has been curious. At first the sound was very vivid, then an aggressively forward sound stage developed, followed by a kind of dry penetrating sound. At near 300 hours it became relaxed and smooth, back to being a Mac, and seems to be continuing in that direction. Resolution and imaging has improved significantly from the already fine original sound. I am inclined to say at this point that the improvement is somewhere from significant to dramatic. I will report back next week.

[David]

I will refer to this report as Part I since better insight could be gained by A/B’ing the upgraded C712 against a more current McIntosh model. Again, I would be happy to make a house call, refreshments in hand, to give it a shot.

I will start out by reminding the reader that any opinion on sound and music is necessarily subjective and, to paraphrase John Nance Garner on the value of the Vice Presidency, it may not be worth a pitcher of warm piss. I have 61 year old hearing. A further disclaimer is based on the fact that I can not do A/B comparisons with the un-upgraded preamp (I don’t have two) and must rely on my memory of how the pre-upgraded C712 sounded. Last as a human audiophile I may be subject to “ new toy syndrom”, the placebo effect , “confirmation bias” , or I could be just plain delusional. On the other hand I am a fairly serious music lover with a preference for classical. I subscribe to the NY Philharmonic at Avery Fisher Hall and occasionally attend concerts at Carnegie Hall. So hopefully without arrogance I feel I can honestly say I know the sound of live music in a real space.

The sound I prefer is the sound of a fine hall like Carnegie Hall: warm, resonant, atmospheric, and clear as a bell. This is why I like the sound of McIntosh.

The exact techniques of David Schulties of the Upgrade Company are kept a trade secret. Generally, as best as I can tell, he upgrades key parts to state of the art designs and materials, like capacitors and wiring, and paints the inside with a blue coating that apparently shields the circuit from EMI/RFI noise and probably dampens the electronic guts from micro vibrations (I’m guessing). He told me he does not change the circuits or do bypasses. If you treasure your Mac equipment as valuable collectibles, the blue paint is obviously not for you. It might seem like desecration to some. My interest is sound quality first, so it did not bother me.

My goal in having the upgrade done was to get better resolution, via a relatively modest expenditure for the high end world, $1,000. Business has not been that great lately. My perceived need to do this was due to the addition of a very low noise DAC into my system. Up until last year I usually only had the preamp in the chain of equipment only when I listened to vinyl. I used a high quality switch box to switch it in. My digital front end consisted of a computer server using a pro sound card (Lynx L22) with the ability use higher out put voltage and thus drive the amp directly. I have been told it is roughly the equivalent to a Benchmark DAC, but it has the advantage of providing very high quality digital recording for archiving vinyl. Last summer I added an outboard Neko D100 DAC to my system. It apparently has a signal to noise ratio better than 130-ESS Sabre DAC territory. It seemed to also work well passively even though it put out consumer level line voltage, but I gradually came to prefer it with the C712 preamp in: better bass and dynamic energy. With the preamp in, though, I missed the transparency of going direct. So my goal was to maintain the character of the sound but get better transparency. Most of the listening I did was through the Neko via kernel streaming (ASIO4ALL) using Jriver, in a 64 bit version of Windows 7. I also listened through the Lynx L22 and to vinyl using my Technics SP10, as well as a few CD’s and SACD’s.

From many accounts, including those from the nice people at Audio Classics from whom I bought the C712 a few years ago, it sounds virtually identical to the non-double balanced Mac preamps, up to the present C46. So to lower the noise level further to take advantage of the resolving power of the Neko, I would have to go to the C500, or maybe a used C200. That seems like an indulgence during this recession. Hence the decision to try the Upgrade Company. My ultimate hope is that the upgraded C712 will approach the quality level of a C200 or even C500.

OK, so how does it sound. FANTASTIC! I would say the most succinct way of describing it is more vivid resolution, weight, and depth of sound stage. Piano notes have a more defined leading edge and decay. I have heard some background sounds that I never noticed before: the sound of a singer taking a breath; pages of music being turned, the conductor shifting his weight on the podium. The imaging has dramatically improved. In the case of certain passages from a full orchestra, I can vividly hear the separate instruments hanging in air between the speakers, much like you would hear from a good tube amp. Generally, I can hear more “air” in the hall. As far as I can tell this increase in detail has been achieved more by lowering the noise floor than fiddling with the frequency response, though the original tonal balance has probably been slightly altered. The sound is slightly more dynamic. My Mac, which has a native elegant smoothness, has not been turned into a Krell. It is still warm and musical, but taken one step back from a near glassy smoothness. I have also heard intermittently a kind of ultra purity and stability in the sound that I associate with a quality SET amp. I am not sure if this is only with some recordings and if that aspect of the sound is still developing. I would guess that one or more of the upgraded components is injecting a touch of even-order harmonic emphasis at times.

I have not done an A/B yet using my switch box and comparing the sound to no preamp, but I have done an A/B of digital (wave files) to vinyl. I have compared the same recording, first digital copy (24/192) of the vinyl, with the vinyl. It was virtually indistinguishable. Digital now has more ease and solidly that I thought came only from a lack of jitter, I guess not. I could tell the difference but only with a lot concentration. This tells me that the digital has been improved, in relative terms more than the vinyl. I suppose because digital sound had more room for improvement.

As we know, and as Mahler has reminded us, music is all about mood. When I was in the mood last weekend, I was up late listening to Mahler’s great Symphony no 2 performed by Bruno Walter and the New York Philharmonic. Recorded in 1958 at Carnege Hall, it has been described as an indispensable recording by the Penguin guide. I have listened to it a zillion times. With the help of my imagination and the improved C712, I was transported to Carnege Hall in 1958 as never before. The epic unfolded musically with nothing but clear air between me and the stage. The space and clarity of the large orchestra, soloists, and chorus sounded more “right” than before, a very convincing illusion. Was this due to the upgraded electronics or my wanting to hear it? Probably a little of both, but we are audiophiles because better quality sound enhances the emotional communication of music.

Although I am at over 550 hours, I still get the feeling that it is settling in. I am about to go on vacation for a week in Florida. I will leave it on connected to a tuner. If the sounds ripens further I will make a follow-up comment.

[Still-One]

David
Sounds like you achieved all of your goals with the upgrade. Very good.
Jim

[David]

Originally Posted by Stillone

David
Sounds like you achieved all of your goals with the upgrade. Very good.
Jim

So far, yes. If the sound still evolves I don't expect it will be for the worse.

[mike175gr]

Delightfully written! Thank you! I have a C712 that I bought from Audio Classics last year and I enjoy it very much. I use it in my bedroom system and I agree that it is a wonderful preamp. Thank you for your review!

[David]

Originally Posted by mike175gr

Delightfully written! Thank you! I have a C712 that I bought from Audio Classics last year and I enjoy it very much. I use it in my bedroom system and I agree that it is a wonderful preamp. Thank you for your review!

You're welcome. I'm glad you enjoyed it. It was fun writing it. I think the upgrade route if done by a skilled company provides an needed option between buying new and used. In the long run it should make the Mac brand stronger by making all models more valuable as an investment and providing more price variety. The option of upgrading could make a consumer more confident the product won't be quickly surpassed by advances. Maybe Mac should consider endorsing certain upgrades as Classe has done or even partnering with the Upgrade Company. Mac could offer an outsourced souped up option--sort of like a Shelby Mustang.

[US Blues]

Thank you for a very thorough and honest review. Your candor regarding your own bias and preferences is refreshing. The articulate way in which you describe your listening experience is as artful as the music itself, and the bit about being transported to Carnegie Hall touches the heart of our passion- the joy of music!

I appreciate your sharing in this journey, and your conclusion certainly are influential to me as a low-budget, high-involvement audiophile.

Thank you and enjoy your "new" C712!

[markjrho]

Hello all, I'm fairly new to this site and this is my first post. First off, there is a lot of great info here from a lot of informed people, so thanks in advance for all that I have read thus far.

I am posting here because I am interested in obtaining some Mcintosh gear. Specifically, I have been looking at the c712, c15, and the c710 preamps. I have found some reviews on the C15 and the C712, and some people appear to prefer the c712 over the c15. Further, I stumbled onto the c710, but I haven't been able to find any significant information on it. I found a site that indicated it was initially made for distribution outside of the U.S., and was later sold in the States. I also understand that it is identical to the c712, but without the remote.

I am building a modest two channel system, separate and apart from my home theater. My two channel speakers are Nola Viper IIa's, and my current power amp is the Musical Fidelity A3cr. While I continue my search for a preamp, I am using an MF a300 integrated amp. Nice, but I know I can get better.

I'm on a budget, so this is why I'm looking at these used preamps. Further, I have always enjoyed the smooth sound of McIntosh gear whenever hearing amps in audio shops, and I believe that a good Mcintosh pre can add something to the sound, and the midrange in particular, in my system.

Any and all thoughts are welcome, but if anyone has any experience with or knowlege of the c710, please share, as I have seen a couple of these for sale recently.

Lastly, David, the upgrade to your preamp sound intriguing. Does the Upgrade Company have a website I can visit.

Thanks again.

[Formerly YB-2]

Originally Posted by David

He uses some Blackgate capacitors which are known to take a long time. I suspect that I will hear improvements well before 600 hours.

While this is an old post, even back in 01/10, if he was using Black Gate caps he must have a hoard of them secreted away as they've been out of production for some time.

Originally Posted by markjrho

I stumbled onto the c710, but I haven't been able to find any significant information on it. I also understand that it is identical to the c712, but without the remote.

Lastly, David, the upgrade to your preamp sound intriguing. Does the Upgrade Company have a website I can visit.

Thanks again.

Only difference is the remote between the C712/C710. http://www.roger-russell.com/preamps.htm#c710

The C712/710/15 are all relatively recent preamps. You would likely want to listen to whichever one you decide on prior to sending off to have "upgraded". If they don't work or need repair, suggest you also consider Terry DeWick. He uses Nichicon Muse caps, which, as the Black Gates have been out of production for a few years, are about as good as it gets for 'lytics' these days.

You can google both the Upgrade Company and Terry DeWick for their websites.

[David]

The C712/710/15 I am told all use the same pre-amp circuit. Their sound is likely to be very similar to other non-balanced Mac pre-amps through the C46. If you can't audition one I would choose based on features. I like a remote. I don't think you are taking much of a chance in buying one blind without an audition. You might check with Audio Classics. The Upgrade Company was a positive experience for me, but you will trade in a touch of smoothness for better imaging and resolution.