Crisp sounding tubes for Modwright 5400ES

Thanks to all of you for your advise. One thing I neglected to say was that I had already switched to using a Mullard 5AR4 and Sylvania 6sn7 GTBs; sorry for that.
I had read elsewhere in Audiogon forums that the Mullard can be a bit 'overly-sweet' sounding, which I take to be overly-rich? So I was looking initially to change the rectifier tube for something which would give a crisper top-end. I read in another forum that the EML 5U4G has a more more open top end. Has anyone tried this?
Jwn, thanks for the benefit of your experience with the Oppo. I did think about this but then stopped when I read the following thread, where their observation was the the Oppo was fuller and warmer sounding. I am sure your experience was valid in your system; I guess that's the thing with our hobby; there are so many combinations and permutations and different outcomes in audio.

http://forum.audiogon.com/cgi-bin/fr.pl?ddgtl&1324431696&openfrom&1&4#1

If your goal is to add more crispness on the top, then I would go with Audience Powerchord for the power cables. I have this pc on all my components now. I would also recommend the Sophias for the output tubes. The Sophias are not euphonic or "tubey" sounding. They are instead linear and 3D. I have the Modwright tube Oppo 83, which I thought was a tad too warm when I first got it. The Audience powerchords and Sophia tubes brought the sound of my rig back into balance.

What are you using for ic's and speaker cables?

I would contact audiogon user Fork on the Create audio 5AR4. I got mine from him. It is not unusual to have to wait. Limited supply and
I hear a lot of people really like this tube. Based on my experience I think it might be a better choice for you. I found the vintage Mullard wonderful, but almost too much of a good thing in the Modwright sony.

I've owned the MW Sony 5400 for quite a while now and for me, it's a keeper. I also have a huge stash of NOS 6SN7's I've accumulated over the years while looking for the best(for me) tubes for my Atma-Sphere MP-1 pre and MA-1 mono's; combined, they use 20 6SN7's!

I use the Mullard rectifier and like it a lot, but as mentioned, it will add a bit of warmth. If you're looking for more "crispness", I'd probably just stay with the stock tube or try some of the current offerings.

As for the 6SN7's, I'd pick up a couple GE 6SN7 GTA's or GE 6SN7 GTB "coin base". They are seriously good and quite inexpensive and they'll give you the open, airy extension in the top end you're looking for. JWM has heard them in both his MW Oppo and his MW Sony 5400 and he too liked them a lot.

Another option might be NOS Tungsol GTB's(not the black glass version). They're also inexpensive and offer a leaner, cleaner sound with great extension on top. As mentioned, there are a few Sylvania "W" variations that may do the trick but they tend to be a bit pricey, especially the nickel base version. The Kenrad VT-231 is also a very nice tube but they often tend to be microphonic so buyer beware.

As for the MW Oppo vs MW Sony debate, JWM and I, while good friends, agree to disagree on which to go with. Of course, there's no wrong choice cuz they both sound exceptionally good but I prefer the Sony.

I spent a lot of time in the Modwright room at this year's Rocky Mountain Audiofest and Dan did several A/B/C comparisons between the stock Oppo, his tube modded Oppo, and his tube modded Sony. EVERYONE agreed, including Dan, the Oppo is warmer and fuller but the Sony is more resolving. Everyone also agreed, the stock Oppo ain't bad but either modded unit mops the floor with it!

After several hours of listening to JWM's modded Oppo vs his modded Sony, in his system of all VAC equipment, I came away with the same impressions. We went back and forth between the two players, and by the end of the night, we pretty much agreed, the Oppo sounded warmer and fuller, the Sony was leaner and cleaner. The Oppo sounded better on mediocre recordings but I thought the Sony made good recordings more exciting and believable. To my ears, the Sony is more resolving, open, transparent, and extended on top. As for which has the best bass, I'd call it a draw.

Solentgreen, I find Mullard GZ32 'overly-sweet' sounding in my MW Transporter. I'm rolling NOS Tung-sol 5u4gb and I think it will work for you.

I know several also find gz34 and EML 5U4G too sweet and highly recommends JJ 5u4gb. I haven't rolled but only $15 so will try soon.

Good luck!