Tube Screaming Preamp

[Chuck]

Getting this one back up after the fall, and updating a bit. This is the Tube Screaming Preamp with a DPDT switch board added for extra clipping options. The board, switch board and 3PDT Wiring Board all came from Barry. The 125BB box came from Small Bear. The stomp switch, short toggle 3PDT on/off/on switch, and knobs came from Love My Switches.  Most other parts were sourced from my stash o’ stuff. D1 and D2 are 5mm clear violet LEDs, diodes on the clipping switch started as 3 Bat41s on top and 3 1N4148s on the bottom. The IC is a TLC2272, I have an OPA2134 and a a batch of 4558s that I may try in this at some point. On initial fire up my impression was that this thing is loud! then I remembered all my guitars have this odd feature called a volume knob (also figured out the effect doesn’t have to go to 11). Using the on board LEDs it is loud and very clean, with the 4148s it has less volume but pushes a lot of gritty dirt, and the Bat 41s had even less volume with smoother dirt. Pulling one of the Bat 41s and replacing it with a 5mm red LED brought the volume level up without beating up the smooth dirt.

Here’s the self antiquing box (not a shot at Small Bear – I used old paint):

And the all important guts:

Thanks for looking,

Chuck

[Playsforfun]

Looks like precision planning and craftmanship to me. Nice 50’s vibe from the outside.

[Chuck]

The top of the 2PDT board is now populated with a pair of Bat41s tented together and a pair of 2N7000s – I’m done messing with that bit. Volume is consistent between the switch down and up, and not too far off the center position. Sweet spot for me has the pedal volume at about 1:30-2:00, gain at 8:00-8:45 and guitar volume about 1/2-ish. I’m a finger picker, so it’s nice to be able to pick lightly and get a fairly clean-ish tone then add a little muscle to get some hair or tweak the guitar volume to get nasty.

I finally have a TS that I like (a lot).

Chuck

[Author]

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