YATS(ish) - almost all-THT, all-onboard overdrive in a 1590A

drew.spriggs

Well-known member
Finished up a micro overdrive for a friend, and for an extra little bonus I laser marked his band logo onto the front. There is a weird shadow as the scaling got all fucked up while doing the marking, so I need to spend a little bit of time cleaning the enclosure up before I hand it over.

Another TS-ish design (Greer Lightspeed-esque, with a couple of parts changed as I fucked up a Tayda order lol), with dual MOSFET clipping and a TLC272 CMOS op-amp. Ended up using a rail splitter for a bias voltage to keep things compact, and it will happily run up to 24v.

I did initially reduce the gain of the second stage a little bit to avoid rail clipping as I wasn't sure how the CMOS IC would sound (due to the higher output from using series MOSFETs), but ended up going back up a little bit more as it isn't as bad as I was expecting.

Originally I was thinking about making a daughterboard with SMD pots, but finally decided on two standard pots (the long-legged Tayda ones) and tone controls on a trimmer to squeeze everything into a 1590A - everything is THT, and onboard, except the IC. I think if I build another I'll turn the control into more of a presence knob as it makes more sense, but as it is isn't too bad. Forgot to clean off the stupid flux before boxing it up (hence the disgusting photos), but I'll throw it into the ultrasonic cleaner when I get a chance.

Should keep him happy!

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That's really cool, and having the switch and jacks all on the same board is something I've been trying to work around in my head. The audio jacks you have here take up so much space on the board, there's no way I could use them as top jacks with a 9v in between in a 1590b. That's my main hurdle.

Is there room underneath the jacks to place short components underneath them? Like resistors etc
 
That's really cool, and having the switch and jacks all on the same board is something I've been trying to work around in my head. The audio jacks you have here take up so much space on the board, there's no way I could use them as top jacks with a 9v in between in a 1590b. That's my main hurdle.

Is there room underneath the jacks to place short components underneath them? Like resistors etc
Not really - you can on the other side of the board that's about it.

I've got an ultrasonic cleaner but use it to clean clock parts; what cleaning solution do you put it in to clean the flux?

Isopropyl alcohol - just enough for the back side of the board. I use the cleaner to heat it up slightly, let it sit for a minute, give it a quick scrub with an old toothbrush then rinse it back in the cleaner.
 
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