Just got my 50w HRM and for a couple of the first hours stuck in a Telefunken smooth plate in V1 and PI, with a Philips/Mullard 12ax7a/7025a in V2.  Vintage GE 6l6's running 34-37mv plate current.  I was stunned at the range of usable tones provided by the amp at a wide range of volumes.  Played it through a semi closed back old Peavey 2/12 Mace combo cab that I modded, filled with JBL g125's in series for 16 ohms.  Fat, full, rich.  Woooooooeeeeeeeeeee! 

I've got NOS JAN Phillips 6L6WGB and just fired it up two hours ago...already think it was a great decision. Very clean and articulate. I biased em to 50ma, as recommended by thetubestore.com and they are amazing!

+1

50ma is much to high  - max 35-40ma.

Dumble amps like a lot of headroom. The tone is happening in the preamp, so no need for high bias.
I run 6L6 bias at around 30ma per tube.

@boldaslove6789

Your comment about the Telefunken 12ax7's got me thinking about the D-style tones i'm hearing on many youtube clips, particularly the smooth compression and harmonic bloom.  Usually they are NOT my fave guitar amp tube, but when I thought a bit about their sonic characteristics I realized that they might work well in my new HRM. 


So I found a NOS testing balanced within 10% 12ax7 smooth plate and stuck it in v1, found a strong Philips labeled Mullard Blackburn factory 12ax7a/7025a for v2, and another strong and very tightly balanced 12ax7 Telefunken smooth plate 12ax7 for the PI.  Then for the same kind of compression characteristics and brighter top end that the ribbed plate delivers compared to the smooth, I stuck a strong, balanced within 10% Telefunken ribbed plate in my C-lator.  I originally started out with a pair of GE VOS 6l6gc's, but later found a pair of VOS Sylvania 6l6gc's on fleabay with Conn organ labels on them, they run balanced within less than a half mv of each other at 38mv.  I have read that HAD used the Syl 6l6gc's in many of his builds.  To help hasten burn in, I left the amp and c-lator hooked up with all boost switches on and OD engaged all night two nights in a row without an instrument cable plugged in,  the trannies were only warm, not hot in the morning.   That made a welcome difference in the amp's tones.  Lacking a better description, the amp opened up more at given gain settings than before as far as harmonic content.

I got exactly the kind of results I was hoping for.  Without the c-lator hooked up I got everything from BF cleans to some nice Marshall-y crunch. (the first Marshall jtm45's used 5881's !!)  I love what the tone, boost, and OD trim knobs do for versatility!  Adding the c-lator without effects to the fx loop gave up the magic sustain goods I had heard, and with some very sweet harmonic bloom.  I ordered my amp with only one mod, a lift negative feedback switch. Using that flipped toward the front of the chassis smoothed out the overall tones as well, more in line with the kind of tones found in the original OTS.  Haven't touched any internal trimmers right now and don't feel like I need to.

SAWEEEEEEEEEET!