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I can't help my self, I like the tc 15 but I want to keep the ef86 channel
and turn the other channel into a trex or plexi type. Has anyone done this before?

Andy

Somehow this question has come up several times recently, under slightly different guises. Here is what I have replied in each case:

Here's what you need to do, referring to the schematic on www.trinityamps.com/phpbb/viewtopic.php?t=859 :

C1 = 0.01uF
C2 = 1uF
C3 (180pF) removed
R7 = 820 ohms
C4 (25uF) remove, or replace with 1uF or 2uF if you want more gain
R15 = 820 ohms
R18, R19 = 330k (increase to 470k for more Marshally power tube distortion)
R20, R22 = 8.2k
R25 = 2.2k (don't use the choke option)
Set the OT for 8k operation if you want the amp to sound more like an 18W.

At this point it still has the Vox style tone stack, and you could optionally put these more Marshall-like component values into the tone stack :

VR2 (treble) = 220k
C5 (treble) = 470pf
R34 (slope) = 33k
C6 (mid) = 0.01uF
R10 (mid) =15k
VR3 (bass) = 500k
Connect pins 2 & 3 of VR3 together.
Disconnect junction of C6 & R10 from Pin 2 (wiper) of VR3
Remove connection between VR3 Pin 1 and Ground
Connect junction of C6 and R10 to VR3 Pin 1 (so pin 1 path to ground is via R10)

And that's it! The Lightning preamp channel is effectively a TMB, although without a Mid control. BTW this gives you an amp with a Vox meets Marshall vibe, that's actually very close to a 65 Amps' Soho.

_________________
Great tones come in small glass jars!

Thanks Zaphod I have room to put a mid control.

Andy

In that case use a 25k pot for R10, instead of the 15k fixed resistor. If you like more mids, you can use a 50k pot for R10.

_________________
Great tones come in small glass jars!