Modwright Oppo 105 - Upgrade Power Supply Tubes?

Bluewolf, you might want to try the new production Gold Lion 5AR4. You can pick one up for about $35-$40, and in my experience, it is better than the old production Blackburn Mullards from the 50-60's that are becoming very rare and expensive.

The new production Sophia 6SN7 is also a very nice tube if you want an alternative to your RCAs at some point

Yes, I use a MODWRIGHT 9.0SE Linestage. The biggest improvement to the Rectifier is a Mullard 5AR4 old stock or NOS.I bought mine from ANDY @vintagetubeservices.com for around $100.00. Awesome tube :-)

I also run the RCA grey glass vt-231/6sn7GTs on my Modwright Oppo-95. They do not sound good with a Mullard 5AR4 (I have a date code F31 Mullard).... IMO, way too much of a good thing, to a point where it sounds dull and slow.

The Genalex Gold Lion GZ34/5AR4 is a decent rectifier with the RCAs. A rectifier that I personally like better with the RCAs is the Philips 5R4GYS that Upscale sells. I think its around $50. Definitely worth trying.

I have used Both the Phillips 5R4GYS and the Sovtech and the Mullard 5AR4..The Mullard is the one to go with.You see in a 5R4GYS vs 5AR4 , the plates are too close together in the phillips and while this tube will work..it is not a good match for the Modwright 5AR4 driven power supply. Find yourself a good REAL Mullard for around $120. You don't need to run a $350 metal base. This tube will tighten the bass and give everything a little more weight.The phillips sounds bloated and blurry in the low regions.

When I had the MW Transporter, Tung Sol NOS 5u4gb was by far the best rectifier tube. It was musical, bloom, detail ... JJ GZ34 for $18 was also excellent and definitely worth a roll.

For reference, I found Mullard GZ34 too warm and rich for my taste.

An extremely musical combination that I am now using (in my Modwright Oppo-95) is a pair of shorty, chrome dome Sylvania 6SN7Gs (w/ black base, green lettering), and an RCA 5R4GY. Very natural sounding across the board, with a great soundstage, and awesome mids. Nothing seems missing in this pairing.

Sorry, I don't agree with the above statement that a 5R4GY is not a good tube match for the Modwright PS9 power supply!

Black Treasure CV181-T was the BEST signal tube in my MW Transporter. I found Sophia 6SN7 to lean for my taste.

Agree completely with mattmiller.  The Philips 5R4GYS has nothing on the low end on the Oppo.  I spent a year diagnosing what was wrong with my system.  I had never even tried the stock tube supplied by Dan.  I was ready to sell everything off in frustration when I made a last ditch effort and changed out this tube. Magic.  Try for yourself and see.