Fairlight,  Repairs

Fairlight, an interesting discovery

So I decided to check a few of the PCBs, now this is a IIx so it should have voice cards with CEM3320 filters on, but no matter where I look I cannot find them.

Fairlight CMI voice board (CMI-01)

After a bit of digging, it seems the owner says it was a I, then upgraded to a II and then a IIx, but it looks like they kept the voice cards from the I. This uses a switched capacitor style VCF (top left using a 4066 and a 4136 quad op-amp).

A friend shared a picture of his Fairlight II voice board and the CEM3320 is on the bottom left (you can see the four red capacitors around it) and it has a lot more trimmers than this one, 7 Vs the 1!

And a Fairlight II board (CMI-01-A)

I’ve been busy reading the service guide that I have and I feel that I’m happy enough with the power supply to now start working on it (with all the boards removed).

First will be to isolate as many supplies as I can from the main transformer and check the capacitors (they are big and many)

Next power it up with these disconnected and confirm if it blows a fuse or not. Currently it doesn’t blow a fuse immediately (with the regular circuits but now load) it takes maybe 2 or 3 seconds. Which makes me think that its unlikely to be the mains transformer.

electronics and synth nerd.