More miniaturised pedals - Teddy Rupture (1550Q) and Thermionic Distortion (1590B)

[CA138]

Hi! I made a couple more miniaturised builds today. The Teddy Rupture fuzz is to go underneath my pedalboard (activated from a loop-switcher up top) and I couldn't bring myself to make the Thermionic Distortion with internal pots, so decided to meet in the middle with a compact 1590B build (using 9mm Alpha pots).

Both sound fantastic, although I get a fair bit of squealing with the Thermionic dimed - I will try to adjust the internal trimpot tomorrow to dial it in better and work in some shielding if needed be. I haven't tested it with the back closed yet so that may help as well.

Has anyone tried swapping out the TL072 ICs in the Thermionic Distortion yet? I've got a bunch of OPA2134 spare but usually save them for cleaner circuits.

 

[jcpst]

although I get a fair bit of squealing with the Thermionic dimed

Mine does this too if I dime everything. I remedy it by putting a buffer in front of it.

Has anyone tried swapping out the TL072 ICs in the Thermionic Distortion yet? I've got a bunch of OPA2134 spare but usually save them for cleaner circuits.

I would be curious about this too. I might just drop the coin for a stash of opa2134s to try in various builds.

 

[CA138]

Mine does this too if I dime everything. I remedy it by putting a buffer in front of it.

I would be curious about this too. I might just drop the coin for a stash of opa2134s to try in various builds.

Hi! Thanks for the feedback. Was worried I may have made an error somewhere. I'll do some more testing tomorrow, including swapping OPAMPs and will report back.

 

[jwin615]

Hope you bought those 9mm a couple of drinks first.
Well executed!

 

[CA138]

Hope you bought those 9mm a couple of drinks first.
Well executed!

Haha! I did feel slightly guilty at first tearing the PCB mounts off and bending the legs like that.. oh whoops

Update on the oscillation/squealing - it goes away with the trim pot turned all the way down. Pedal still sounds great, with no buzz/hum/noise, but I am definitely losing out on some gain - not a big deal as the gain pot on max is more than I would need most of the time. The LEDs light up on pick attack like they should.

For Jcpst - swapping to OPA2134s didn't change that issue, and in fact the pedal didn't sound as good as with the TL072s so I've swapped them back in.

I did a lot of grounding testing and tried with the back plate on, which didn't change anything. Pretty sure it isn't a grounding issue.

Very happy as it is - but keen to try any other ideas to be able to turn that trim pot up at least a third of the way for more gain options.