Found 2 major design flaws of the Ming Da:
1. Filament power supply in series, 2 supplies, one shared between 2 6SN7 and the other among 3 6922, non regulated.
Be prepared for it to sound good one day and bad on another.
2. Grid resistor from 6SN7 stage to 6922 stage is 1/10 of what it should be. In the unit and the schematic there is a 220Ohm resistor but with that you'd have to have a 6SN7 and the middle 6922 to perfectly jive with each other to avoid a high frequency oscillation which sometimes has the side effect of inducing a pronounced hum as if grounding is not proper.
This is why this preamp is both a tube-roller's dream AND nightmare.
Took me a while to figure it out. Swap in a 2-5k resistor and all is well. |
Tried the stubby Syl chrome top in the regulator and RCA smoke for the input/gain stage 6SN7s. Sounds OK but top end is colored (there's a frequency in the mid high thats recessed and a little above that its pronounced).
I think tube-rolling among these competent NOS tubes (not EH not Sovtek not Shuguang) will only give a different flavor but wont contribute to night and day improvement or fix a "problem".
I'm happy with my smoke-glass regulator and CBS combo for now as the new coupling / output caps settle in.
Bass is still lethargic (not nearly as bad as the SLP98P I owned a year ago). I strongly suspect its the 0NFB design. |
Mr Wu, are you mixing the 6sn7's? Maybe two grey glass and the short bottle Sylvania?
Otto, if you have not done anything yet you may want to wait until Mr. Wu gets done evaluating. I love mine though if that helps. |
I owned the Cary SLP98L for nearly three years and it is an excellent preamp in it's price range. It presents a very good soundstage and is very musical. I was very happy with it, but decided to upgrade to an Audio research preamp. I also found it to be very transparent and accurate. It sounds even better with vt231's or 5692's if you are after a more mellow sound. |
Regarding the Ming Da MC-2A3.
Am already using RCA2A3 for rectifiers, GE british EL34 for regulators,
and swapping from among my RCA smoke glass, CBS, stubby Sylvania chrome tops, and KenRads.
Each combo yields a different flavor (color) and I am having a hard time deciding which one's best. The only thing I can say is that any of the
above NOS is better than the stock EH.
Also swapped out the "Philips" lytic cap next to the 6SN7s for Black gate 350V 150uF, and the "BC" lytic in the regulation circuit for Mundorf Lytic.
I am hoping it will make the bass tighter (cant expect too much afterall this is a pure zero feedback design).
Coupling caps/output caps are swapped to Jensen 0.22uF and Mundorf silver oil 2.2uF.
Things are settling in (the initial brightness of the Jensens are starting to fade) so I cant really give a verdict yet. |
For $800 I don't know any better the this puppyCheers |
The Ming needs all the tubes replaced. It is a fantastic pre-amp and not just a bargain. Modifying this would only add a bigger smile. Just plan on spending some good money on the top tubes. RCA 6sn7 Grey glass is a must with maybe a Ratheon 6sn7gt in the power supply position which I believe is the left position. Lots of combinations with this pre since there are 4 different families of tubes. You can't even begin to compare this tube to anything until you tube roll. The stock Chinese tubes hold it back in a big way. |
The Consonance sure looks enticing, the tube config also looks right.
(Love them 6SN7s)
The concern is whether Consonance can build a 6SN7 preamp
thats quiet and not bloom-and-gloom bloated.
It would be great if the inside is point to point wiring
(potential for turning the thing upside down into a known-world-class design if it comes up short)
But for that price I guess you cant go wrong. |
I have many years in the Audio field ,and for the moneys I have listened to and compared notes on parts quality
value and sound , for a 6as7 based preamp , the New Consonance cyber 222 Mk-2 is a real gem it has it's own
seperate outboard power suppy, it now uses Auri cap capacitors and 1% film resisitors and uses a micro processor controller relay for the volume panel.
The unit weighs over 33 lbs ,it was at $2000 and was lowered and improved how many companys look at how to do both and succeed.The build quality is as good as any $4000
unit I have owned .I put in a decent power cord, replaced
the EH 5ar4 with the Best MUllard which has much better control and dynamics , and a matched quad of Chrome dome Sylvanias from the 1950 for under $300 for the tubes,
you now have a pre that will go toe to toe with most any $4k unit ,and do compare apples for apples for value. |
I wrote a mini-review on the CA906 and submitted it to www.high-endaudio.com.
Just bit the bullet on a Ming Da MC-2A3.
Not nearly the same class as the CA906 in terms of build
(I have NEVER seen layout and soldering as good as Canary products),
quality of components used, and most importantly sound but
there's a big difference in price.
Ming Da MC-2A3's hopeful for mods given the space available inside and rather easily understandable layout. Weird power supply though,
gives all the attention to the B+ not zero regard for filament voltage.
Also not all MC-2A3s are the same... some boasts M-Caps and other
premium components. Mine has MKPs and what looks like Vintage Gudeman. Also the 'Philips' caps look suspicious.
If I had ample $$ I'd go for the Canary 906, but the Ming-da is gonna be quite a bit of fun I suppose. |
I had the opportunity to listen to a Canary CA906 (2 6sn7s per channel with extensive tube rectification and regulation) in my system with both the VAC Phis and NP220s.
This is probably the best production preamp I have every heard.
Details later. |
Thank you all for your suggestions. |
there seems to be a 6sn7 variant of the aikido I think is worth looking into. |
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Polk432 are you hinting that the MC-2A3 is a fraudulent listing? Or are you referring to an SLP98P? Seller of the formet seems to be some shipping liquidator. |
Get the Cary SLP98P !! EBAY customer service may agree. 1-800-717-3229 |
I have listened to Antique Sound Lab Flora EX DT and liked it. If you have not tried it yet, you may want to give it a try.
One thing about 6SN7 is that it is very tube dependent. I am still searching for a 6SN7 that is good for vocal, Jazz, and Classical music.... |
Also Mapletree audio. Never heard it but priced right.
My Dehavilland Ultraverve is the best so far. I don't see too many Ultraverves come up for sale compared to others. |
The Aria basic WV11 is still $6350.
Not anyone can afford it.
Since the thread starter is interested in 6SN7
I could only recommend Melody 1688 Signature
or TubeCAD.com DIY boards for the Aikido 6Sn7 balanaced design) , or get Scott Frankland (local in the Bay Area) to custom build an MFA line stage for you.
The Ming Da 2A3 seems like its not purely a 6SN7 preamp.
The 6922 seem to be used as followers. |
I feel that Albert's advice to talk to Mike Elliot is a great place to start. If you like the sound of the SA11, it could be difficult to compromise on a line stage of much less performance. And Mike is in a position to do custom work on a per-customer basis that is just not possible with the big players (ARC, BAT, CJ, Aesthetix, etc.) because of their association/dependency of a dealer network.
Unfortunately, the SA9/SA11 upgrades really make no sense any more with the advent of the Aria WV. For the cost that it would take to get stock SA9 and SA11 models, bring them up to top-upgrade status, the new WV ends up being about 1/2 this cost. Once you subtract the need for the IC and the 2nd PC, the cost is truly a bargain. And from reports by people who owned these full decked-out SA11/SA9 combinations, they have sold them due to the WV's performance. Same designer, a lot of knowledge and experience carried over, but the opportunity for a clean slate design.
I have heard from other designers that have tried to optimize a 6SN7 line stage design and it seems to turn out to be too noisy. I think the desire to use this tube stems from people wanting a different sound/performance than the 6922 tube often used for this application.
And that brings on the value of the WV. Even though Mike has designed the WV's phono and line stages around the 6922, with a flip of a switch, the line stage can run with 7062/E180CC tubes....and let me tell you, this is a revelation...over the top priced pinched waist Valvo and Amperex 6922. For me, there is no going back to the 6922 tube here. The next thing is to look into the 7062/E180CC support for the phono stage.
If you only need a line stage, the WV can be ordered as such for about $1500 I believe. That takes the tube count from 8 to 6, with 4 of these as the power supply.
The size of the WV is about the same as an SA11 but maybe an inch or so less in height. It houses its power transformer in a separate chassis connected by an umbilical cable.
Unlike Albert, I was never able to afford the top Counterpoint models. But I have much experience with the very magical Aesthetix Io and Callisto Signature products after being a long time ARC and BAT fan. And my preamp evolution has recently shifted to the Aria WV. Its simplistic design brings on a wave of new information I never knew existed. And the major reduction in tubes and the multiple huge chassis makes this one of those rare events where something much less in cost and required shelf space result in the next level of performance.
So do yourself a favor, and contact Mike Elliot.
John |
Allow me to keep ranting... just by looking at the picture of the inside of the Ming Da MC2A3 I'm already thinking it could use much better high voltage bypass, better coupling caps, and hexfred bridges.
Have you also considered the Melody 1688 Signature?
I know Taurus @ Fremont (or was it Newark?) has them. |
Yu11375 you must be referring to the MC2A3 currently available on Ebay...it does look interesting.
I am in the Bay Area, maybe one of us should take a chance then trade.
Problem with Ming Da based on my ownership of the MC7R is that they know how to build stuff but they dont know how to voice them.
Cary SLP98P... I had it for 3 months or so driving my then NPM Basic and VAC Phi 70 monos. I was overly optimistic enough to think that the Cary can hang with my friend's MFA lumi (wrong!). With the right tubes it does pretty well but it tends to sound a bit am-radio-like when playing complex passages. it was slightly bettered by my (then) SP10II.
I dont think anything can come close to your SA11.
BTW I use an NP220PG, loving it. |
I can't do a comparison with your other candidates but I'm extremely pleased with the AES AE-3 DJH Signature preamp I'm using now. It's got a small footprint that might help in the setup you describe and is incredibly well built with all point-top-point wiring and tube rectification. As one of the reviews of it said, "We will go out on a limb and say this: The AE-3 DJH competes with cost-no-object preamps from ANY manufacturer." |
Got a Cary SLP98P in Feb 08. then got a CaryV12R amp 2 weeks later. Sounds fantastic. I may go for a pair of Gallo 3.1's to replace Krause Cinema Extremes. Anyone ever heard these? |
Try the Atma-Sphere MP-3. It's a killer. |
Well, as a Supratek Chardonnay owner, I will have to recommend a Supratek preamp. I know, Supratek closed its doors, but I believe they still have some Chardonnay's or will still be making them. Anyway, they get to this pages often
Go to the Supratek Threads and you will find tons of info.
The Chardonnay sounds fantastic, even with a SS amplifier i use. Plinius btw. |
The deHavilland Ultraverve has one 6sn7 tube, two 6ah4 tubes and one 5aw4. Amazing sound with the right vintage 6sn7! |
Hi Gentlemen,
Thank you for all your suggestions. But I am looking for a pre-amplifier more MANAGEABLE than SA-11 (17 tubes in total) for my SECOND system.
By the way, Mike stop upgrading SA-11. |
The original Blue Circle BC21 uses 6SN7 tubes.
So does the Rogue 99 and 99 Magnum
So does this preamp.... :-)
[url]http://forum.audiogon.com/cgi-bin/fr.pl?rprea&1070983438[/url]
. |
Another preamp with these tube is top of the line of Cary Audio
All The Best
Rafael |
Why don't you contact Mike Elliott at Aria and see what magic he has in store for your SA-11?
The Counterpoint SA-11 and SA-9 were my reference pieces before Mike built the EASE and my final evolution into Aesthetix.
The Aesthetix Callisto uses 6SN7's too, in addition to many other tubes, just as the Counterpoint does. |
