MB Freekout... No Holds Barred!!!

[danfrank]

I had a lot of fun with this one. Hopefully MB brings this one back, or gets more boards in.
It's a weird little pedal that makes a lot of weird sounds. I had to put a UV/violet LED to make it even weirder.
I like how the power supply in this pedal uses a LT1054 to make the negative rail off of the positive voltage rail... But that wasn't enough for me! I had to put another LT1054 in the box so this thing can run off of a common 9 volt power source. AND, I'm using a LM2937-15 LDO regulator instead of the 7815 reg. Voltages are +14.91 and -14.51 volts to the ICs. This thing consumes around 40-45ma from the 18 volt rail, so it all worked out.
So how does it sound???
Listen to any of DEVO's early albums

[danfrank]

One more thing... Mouser, Digikey, maybe others are out of the AD633 in DIP package. There's a guy in Texas (not me or affiliated with me) selling AD633s for about half price of the the above sites and that's what I used. The chips don't look right the way they are engraved but they do work in this project, so I guess they're legit ICs. I'm assuming that they are engineering samples, because the writing on them looks hand etched. Strange.

One more thing... Is it normal for there to be a slight whine when all the controls are turned fully CW? I don't think I'm getting any clock noise from the two LT1054s but I'll try a TC7662 on board instead of the LT1054. There's a 10kHz clock difference between the two different charge pumps and I know the negative rail is less than 20 ma, much less, so the TC7662 should be fine.

Quick Edit: The 2 LT1054 ICs are much quieter than with a TC7662. Moving the T1 null helped a lot also.

[cooder]

Very nice, great build!

[moosapotamus]

Great looking build! Love the addition of the 3PDT-05 to allow for standard 9V supply voltage. I just got a Freekout PCB. Wish I saw your post before, so I could have ordered one of those at the same time. Thanks for posting. I'm looking forward to building this one!

On another matter... Skimming the ICL8038 datasheet and it looks like the ICL8038 is set up to only provide a sine wave to the AD633 in the Freekout. But, the ICL8038 appears to be capable of also producing square and triangle wave forms. Anyone ever considered modding this to add options for square and triangle? I gotta think the answer is 'yes,' but I would be interested to hear what folks think.