- This topic has 11 replies, 3 voices, and was last updated 2 weeks, 5 days ago by
.
-
Posts
-
As the title suggests- just finished a Sunn T build and it works as it should.
I’m plugging it into the effects loop of a Fender Super Champ XD (I modded the amp to add an effects loop a long time ago- works but has no master volume control of its own so volume adjustment comes from the preamp pedal).
All works and sounds great, but I’d like a more volume on tap from the Sunn T to get the amp a bit louder. Not looking for more or less clipping or anything, trying to keep the mod clean/transparent and just add maybe 10-15 more dBs or so?
Wondering if anyone could suggest a mod to add to the Sunn T that might be a good addition to get this accomplished while keeping the sound of the Sunn T board generally intact?
Thanks!
Now I’m not 100% fets aren’t my strong point but I’m thinking changing Q4 source resistor R10 to a higher value might increase output the logic being less signal will get dumped to ground through it
I’d socket it and try 100K in there
It also might mess up the biasing but you should be able to re adjust that via TR3
How much it’ll mess up the circuit I don’t know it being between a gain stage and the eq section but changing only 1 resistor it’d be easy enough to change it back
Let us know if you try it
Love that idea, Billy! Quick question isn’t R9 the source resistor for Q3, and R10 the source resistor for Q4?
Guessing may be a typo in the previous post and that Q4 is what you think should be tweaked given the reference to R10 and TR3?
I’ll give it a try once confirming the above (or confirming I’m wrong).
Oh man. Now I’m really confused. R10 is100K already… right? Maybe take R10 to 200K?
Working from: Sunn-T v3 2021
I dunno, I think I get the gist. I’ll socket it and just try stuff.
Apologies I’m looking at an older build doc where it’s 47K must have been changed in the latest version
I’ll need to update all my gpcb build docs on my PC
I should know better that used to be our mantra here ‘are you using the latest build doc?’ haha and here I am not
I’m doubtful increasing its value will make much difference
You could try it or wire a pot as a variable resistor and try that
I wired in an A1M pot instead of R10. Really not much of a change at all no matter where on the sweep it is- though at lowest resistance the signal goes to ground. I can tell a minute difference – it is audible but negligible.
Oh well- it was a good idea and I’m glad I tried it despite my general dislike of desoldering a perfectly good resistor and a clean joint!
In addition to the GPCB schematics above, would either of these Jack Orman boosts be good?
or
I love the simplicity of the muffer, but thinking the MOSFET Boost would be cleaner?
Might be a bad idea, but I’m also probably going to try running the Sunn T at 12 and18V to see what that does. Hopefully won’t melt anything.
As long as all your caps have a sufficient voltage rating 18v will be fine
If I’ve ran out of stage 3 mini pcbs
I usually just build a quick duende boost if I need to increase output and I’m in a hurry
http://tagboardeffects.blogspot.com/2013/04/escobedo-duende-jfet-jhs-minibomb.html?m=1
I’ll use a trimmer instead of a pot so I can set and forget and just add it at the input or output of my main pcb depending on what it is
In your case I’d probably put it on the output
Thanks all for the help. I wound up just putting that Muffer circuit on a small veriboard right before the A100k volume pot. Happy to send the layout if anybody wants it. I’d say it does change the sound a tiny bit but mostly just adds volume.
Fun to explore the ideas and options. I’m sure there a better solution but this gets me there. Thanks all!
- You must be logged in to reply to this topic.