6SN7 based Pre-Amplifier

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.

For $800 I don't know any better the this puppy

Cheers

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.

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.

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.