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TomWhitwell / TuringMachine

Turing Machine Mk 2 Main Module
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No endless randomness #156

Open oorwell opened 3 years ago

oorwell commented 3 years ago

Hi there,

I recently finished building the Turing Machine mkii. This was my first DIY project (not counting very small hobby kits to practise soldering on).

I am super stoked to have actually calibrated it and see it turn on.

The issue I'm having is that the 12O'clock point is not endless randomness. This acts more like a switch, where once I go left past 12 to 11, it creates 1 random double-length sequence, and then once I turn right past 12 to 01, it creates 1 regular length sequence. It creates new random cvs and patterns each time I swing past 12O'clock, but locks them instantly. There is no bringing it back slightly from hard left or hard right to introduce randomness. When I hold "write", it clears it, but I have to turn it past 12 to introduce a new random sequence.

It's still highly rewarding to have it play some randomness back, but I'm thinking I should be able to get it producing some full random goodness, too. I'm wondering if maybe an IC is damaged?

I made a mistake on the "Jack PCB" where I had soldered the TL074 and DAC0300 before the sockets went in. I hadn't had much practise with de-soldering, but managed to get them off after a few attempts. It didn't look like the PCB was damaged to me, but the TL074 had a leg come off so I ordered another one from Thonk. I ordered some extra sockets, too.

I soldered the sockets in this time, and noticed they had reacted to the heat. Not too bad, everything seems intact, but one of the legs has moved up in to the socket ever so slightly. I thought this would be OK as the solder could still establish and complete a connection to my knowledge, and I didn't want to risk de-soldering again as it was a tense time for me!

So I think maybe there must be some damage to an IC, IC socket, missed a solder joint, or my soldering just isn't up to standard for this!

Any help is greatly appreciated, but I can still make some sweet old bleeps!

Thanks, Oliver

oorwell commented 3 years ago

Update:

Opened the device up and cleaned the boards, re-flowed each joint and inspected with a magnifying glass. Still got the same issue, but my hunch is as above: IC chip / socket damage.

I foolishly didn't get a photo of the boards, but I realise now it will help a lot, so will have one soon.

Thanks, Oliver