20th XTC preamp tube cocktail

[steve_k]

Messed with the preamp tube combination in the 20th XTC. With the SED Winged C 34's in the power section, here's the kick ass combination I settled on....

V1 - Ei ECC83 NOS
V2 = Sovtek LPS balanced
V3 - Ruby HG+
V4 - JAN Phillips 12AX7WA NOS
V5 - EH 12AX7 balanced PI
V6 - Sovtek LPS balanced

This really rounded out the upper mids and top end and kicked the bottom end up a notch and tightened the whole thing up.

Steve

 

[tcrash]

when i had mine I ran:
v1 - Amperex nos
v2 - Tungsram
v3 - Tung-sol reissue or telefunken smooth plate
v4,v5,v6 - chinese
This was a great combination
I run the same tubes in my PT100 and it sounds killer also.

I've got a 20th on the way, looks like more experimenting. I'm gonna give your comno a shot...

 

[steve_k]

Cool. Looking at what you got there and what I did, they are a little similar in key spots. V1 obviously sets the pace and V2/V3 are probably the most critical at controlling the gain characteristics of the amp. I always try and run something balanced in V5. But, V4 looks to be not only the FX driver, but a cathode follower and put a mil grade tube there. My previous set up was an LPS in V1 and Ruby HG+ in V2 and HG in V3. The Sovtek may have choked the amp slightly in V1 but V2/V3 got a little edgy with the Ruby selection back to back. So, not sure if it was a change in V1 or V2 for mine, moving the LPS to V2 to tame and widen it up a bit for Channel 2/3. Anyway, it is just right now and a nice thick bottom end with lots of punch and more controllable in the top end, with the mids a little more less annoying to deal with.

And, as always, a matched quad of SED Winged C's in the power section adds to the bliss!

Thanks for the input.

Steve

 

[Oz Hofstatter]

I'm still experimenting the. preamp tubes.
I like a lot so far this configuration:
V1: NOS Mazda Chrome Plate
V2: NOS Mullard
V3: NOS Mullard
V4: NOS GE
V5: NOS EI (love this tube for phase inverter)
V6: NOS Amperex Bugle Boy
I need to try yet my NOS RTC, and of course, go back and forth with the current JJ Tesla, Sovtek, Tung-Sol, etc. I didn't like (noise) RFT and Tungsram (maybe bad tubes for noise, but very good for tone/overdrive).
Cheers,
Oz

 

[tcrash]

when i had mine I ran:
v1 - Amperex nos
v2 - Tungsram
v3 - Tung-sol reissue or telefunken smooth plate
v4,v5,v6 - chinese
This was a great combination
I run the same tubes in my PT100 and it sounds killer also.

I've got a 20th on the way, looks like more experimenting. I'm gonna give your comno a shot...

Just got my 20th back,
been 3 days with this box of preamp tubes and here's where I'm at:

V1 - EI ecc83 (quite a bit of different than the Amperex)
V2 - Tungsram (spent a lot of time here, between an amperex and the tungsram. Both sound great
just a little different flavor. Might switch depending on the cab.)
V3, V4, V5 - chinese

Everytime I get ch.2 Big, Crunchy and Thick. - Ch3 gets thin.
The EI in v1 seems to get rid of some of the low-mid honk on ch2
The Tungsram in V2 seems to open everything up, but, the Amperex in V2 compress' a little and smooths everything out.

 

[steve_k]

when i had mine I ran:
v1 - Amperex nos
v2 - Tungsram
v3 - Tung-sol reissue or telefunken smooth plate
v4,v5,v6 - chinese
This was a great combination
I run the same tubes in my PT100 and it sounds killer also.

I've got a 20th on the way, looks like more experimenting. I'm gonna give your comno a shot...

Just got my 20th back,
been 3 days with this box of preamp tubes and here's where I'm at:

V1 - EI ecc83 (quite a bit of different than the Amperex)
V2 - Tungsram (spent a lot of time here, between an amperex and the tungsram. Both sound great
just a little different flavor. Might switch depending on the cab.)
V3, V4, V5 - chinese

Everytime I get ch.2 Big, Crunchy and Thick. - Ch3 gets thin.
The EI in v1 seems to get rid of some of the low-mid honk on ch2
The Tungsram in V2 seems to open everything up, but, the Amperex in V2 compress' a little and smooths everything out.

You need to get that Chinese out of V3. Throw a Tung Sol in its spot.

I posted this in another thread, but I spent a few hours last night on the 20X and having some of the same tweaks to make. But, I was trying to get the Red channel to dependent on tweaking the Blue channel first. I think the best way, is to get Channel 3 where you want it on the EO. Use the excursions to help get a big thick bottom end.

Then work you way back to Blue channel. I put mine in Plexi mod and made small adjustments to the EQ.

Steve