I recently ran on to a handfull of good vintage 12AX7s from the 50s & 60s. I have 2 RCA long gray plates, a Raytheon black plate, and a really nice Sylvania 7025. I also got a pair of Siemens EL34s from the 70s.

I have to say that I am now a beleiver in vintage tubes. With all of the old AX7s there is more harmonic content & responsiveness than any of the JJ, EH or Tung Sol stuff I tried. There is an exceptional quality to all the old tubes I tried that new production just can't emulate.

In V1, the RCAs have a very rich sound but a little less detail than the Sylvania or Raytheon. They have a warmth & and almost touchable quality when run clean. 

The Raytheon is very detailed and airy. Very clear sounding with a nice even tonal response. Not as rich as the RCAs. Very responsive tube as well.

The Sylvania is right in between the other two in richness with a little more forward midrange. Excellent OD tone. There is so much detail, even with the drive at max, that every note in a chord rings clearly and remains listenable. This is a quality that new production tubes do not have at all.

I found that my favorite tube set up is an RCA in V1, awith the Sylvania in V2 and a Tung Sol in the PI. Of course the NOS Siemens/RFT EL34s help a great deal.

Everyone's taste is different but I highly suggest trying some good vintage preamp tubes. Not everyone will hear things the way I do. Some different RCAs, Sylvanias & Raytheons may sound different as well but they still all out performed the dozen or more new production tubes that I have on hand.

I like having a few different amps. I intend to build a switching bank for stage use & set up my HRM, JTM 45, Vibrolux and Plexi 50 for live shows.

I'm going to incorporate it into a pedal board.

Funny you should say that Mcinku. I am considering a TW Express AFTER I finish my 1965, JTM 45 replica. I am really happy with my HRM though. Part of A. D.'s mystique was that he tweaked and built his amps for specific players. That is exactly what I decided to do!

Hi Folks!

I posted this elsewhere before I noticed this thread. Sorry about that!

After tweaking for 9 months I decided to leave well enough alone. I changed to SoZo caps of different values here & there & tried a multitude of different tubes. I finally settled on Tung Sol EL34Bs in the output.

I changed the bias resistor to an 820 ohm. That gets it right where it needs to be. I am running a Tung Sol 12AX7 in V1 and Ruby HG (JJ) 12AX7s in V2 & V3 with the Tung Sol EL34Bs in the output.
 
The T.S. 12AX7s are probably the best new production AX7s availible. They have a great clarity & detail. The EL34Bs are really great. They are the most well built tubes I've ever seen. Very thick glass & VERY well supported internally. They have more midrange than a 6L6GC and more bass than a standard EL34. Nice sparkle on the top end as well. The overdriven characteristics are like an EL34, with great presence & a little less compression than a standard EL34. The HRM is a TONE MONSTER with this tube setup.

The cabinet is made of sassafrass with a mahogany face plate. I'm running one Eminence Man -O- War & one Eminence Texas Heat in the cab. The speaker cab is partially open back with the handles cut out & left open to let it breathe a little more. I tried several sets of speakers & different cab designs but this sounds better to me. I'll try to get some sound clips soon.

I just replaced my Celestions with one Eminence Texas Heat and one Eminence Man-O-War. Man what a difference. The mids of this pair of speakers really make the HRM sing. The bottom end is nice, big and defined. The highs at first are kind of rough but once they are broken in the highs smooth out and are very, very nice.

I just finished my HRM last week. I worked out all the bugs but one. The bass pot has no effect at all. I have checked my wiring and with a multimeter the pot is working. What is going on with it? Anyone else have this problem?

I just loaded a 2X12 cab with one Eminence Texas Heat and one Eminence Man-O-War. What a great combination. The cab did have Celestion 70/80s in it. The 70/80 speakers are just plain and lifeless. The Eminence pair have a tight, punchy bottom end with great mids and just enough highs to be clear but not tiring to the ears. Really makes my HRM shine!