6SN7 based Pre-Amplifier

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.

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.

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.

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.

there seems to be a 6sn7 variant of the aikido I think is worth looking into.

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.

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.

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.

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.

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.

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.