Hey guys, I just recently bought a used Rivera Knucklehead KR55 top with the Headmaster (running that into a custom 2x12 with a v30 and a WGS Reaper 50) and am looking to experiment with the pre-amp tubes. It currently has the stock tubes (2 Sovtek 12AX7 LP's in V3 and V5, 3 Sovtek 12AX7 WA's in V1, V2, and V4, and 2 Sveltana EL34's). Here's a copy of the description of each pre-amp slot from the manual:

V1 Input buffer and tone control driver for Channel 1, and also the first Preamp stage of Channel 2 and Channel 3
V2 Tone control follower for Channel 1 and an additional gain stage for Channel 2 and Channel 3.
V3 Third gain stage for Channel 1 and final gain stage for Channel 2
V4 Final gain stage for Channel 3 and mixer for both channels
V5 Phase inverter driver tube for the power amp section

I play Worship music and Death Metal , so I am definitely taking advantage of the versatility of this amp. I'm boosting the front end with a TS9 (a Hardwire DL-8 Delay, Holy Grail Reverb, and Behringer EQ-700 EQ pedal when I play Worship music).

I am pretty happy with the tone I am getting now, I am, however, looking for more definition/harmonics on Channel 3 and maybe a little less bass on Chahnel 1 and 3, I am having to use the FX loop trick in order to tame the power-amp for volume, this thing is ridiculously loud.

What tubes would you recommemend?
Got a question about Baritone guitars? Feel free to PM me.

Thanks to UG, I converted from Metalcore to some "real" Metal.
Last edited by Metalcoresoul at Sep 23, 2010,
I would get some JJs, a Tung Sol and maybe some Shuguangs. Try the Tung Sol in V1 first then V4. Mix and swap the others. I've also had good luck with Penta Labs 9th gen and JAN Phillips. Mullards for pres are great too I hear if you like JJs. JJs are darker, Tung Sol brighter (brightest of the lot).

I recommend:

eurotubes.com (not in europe)
hotroxuk.com (in europe)