trinityamps.com

Hello

OK. So I'm just waiting for a couple of parts in the mail and I'm going to be rewiring the "normal" channel of my amp and adding the VRM.

With the help of the helpful people on this forum I've decided to remove the EF86 channel from my 18watt sIII based amp and go with the "normal" channel from the Trinity sIII. The only difference is I will have 1 extra 12AX7, so instead of the "high/Low" input scheme I will have "single/parallel" triode inputs on both my normal and TMB channels.

I currently have a "high cut" control on the front of my amp which I will no longer need, so this will be replaced with the 1M VRM control.

Now. Here is where I need help. Due to the different input scheme I am not sure how to implement the input mod for scratchy pots for the VRM. I currently have the standard "Lite parallel/single" scheme with a 20K resistor connected to each triode input.

Any suggestions?

You've seen the input mod in the resource section? viewtopic.php?t=1176

Can you not do this mod and still switch in the parallel triodes?

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Can I?

Here is a rough idea of how my inputs are wired. One input gives me single triode and the other gives me parallel.

Put 0.1's on pin 2 & 7. Connect 20K to them Put the 1M's from pin 2, 7 to ground. OR just try the 0.1 on 2,7 . It might be OK.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

OK. so put the 0.1s between each 20K and triode input(2,7).

If I use the 1M to ground on 2 & 7 do I remove the 1M's I have installed on the jacks like in your reference drawing?

This i what I was thinking of doing but I wasn't sure if I should use 2.2M resistors and .047 caps instead if the original values because when in "parallel" mode my resistance would be halved and my capacitance would be doubled. I guess this may not be good in "single" mode.

The more I think about it my previous statement is false. the caps and resistors will never actually be in "Parallel" in the electrical sense. They are connected to 2 separate triode inputs. Just hooking them up like in Coco's VRM reference section should work fine. I will just need 2 caps per channel instead of one.