[SpookyZalost]

Finally decided to make a new Project Journal since I came across what should be an interesting challenge.

I recently got for free an ADC S-1 MKII, vintage circa mid to late 70's, maybe early 80's.

was pretty beat up, but was intact otherwise.

side note, this unit goes for anywhere between $40 and up to $70 working.



it's not even a full featured one as it has only 5 rather than 10 sliders per channel but it'd be a fun restoration nonetheless.

Here's the unit as I got it.





Pretty beat up but the internals are hopeful and the potentiometers for the frequency adjustments slide smoothly, likely just need a good cleaning and a bit of silicone grease to lubricate them.

part of my plan is to replace the wood part of the case by fabricating a new one, it's just a simple 3 sided box with a lip on one side to attach to, should be able to come up with something and either paint it or leave it with a nice wood grain finish.





also going to change a couple minor things to update it a bit and make it easier to service in the future.

here's the power supply which I'll likely need to replace due to it's age.



so a few things of note.

several capacitors have started leaking though the traces are not on the capacitor side so that's good news, means there may not be any damaged traces.

(edited, yes there's no obviously damaged traces, it's a single layer board, hand drawn too by the looks of it).

at least 3 resistors are damaged, and all components are still available except for the transistors but I can get them pretty easily on ebay if needed.

when I get the chance to go over everything I'm going to write up a component list and try to reverse engineer the circuit as I go along with my multimeter as well as note which components are faulty, that'll be the next update.

I'm super glad I didn't plug it in to test it first given the state the components are in, but I can fix it for less than it's worth

oh! and it has all the slider knobs btw!



they just need a good soak in some warm soapy water and an air dry.

Update:



the wires are fairly short so I'm going to need to note which ones go to which pins (which are numbered!!!!), De Solder them, Then Remove the board

The great news is, it's a single layer board, the components are mounted opposite the traces so nothing was damaged by the leaky capacitors near as I can tell.

Definitely 1970's.

the traces are not electronically drawn, they're curved instead of straight angles which is a pretty solid indicator.

The good news is, that makes reverse engineering it easier since being single layer and hand drawn means you can visually connect what pins on what components go where.

the pins themselves are marked on the side they sit on so this should be pretty easy once I de solder the wires holding it in place.