Here is an old skool mixing desk. Customer was desperate to have this repaired, he loves pure analogue. Well, the desk had seen some service for true. I couldn’t find too much on this Eaton Bray 12 to 2 desk. Not a digital processing chip in sight. First thing that was found, was no right channel output. So off with the base cover to reveal a lovely ‘70s design. Now, I get a lot of desks in for repair, Behringer and clones alike. Yes they are feature rich and cost 2/3rds of F all, but try and repair them. SMD components, 10,000 nuts and screws and if you get one OP amp taking down a bus, then good luck trying to find it. But with this beauty, all is accessible, proper components that you can access and change, sliders and potentiometers that you can change without submitting yourself to a mental asylum. A quick look around and found the right channel audio bus had a DC offset. Naughty. Easy to isolate, lift off both channel feeds from the input mixers to start with. This proved all the 12 channels were okay. The amplifier and meter drive board showed different DC conditions between left and right. Then we see the awful Tantalising tantalum capacitors and we all know what they like to do when nobody is looking. Change them anyway. We have a nice mix of transistors and OP Amp ICs. The DC offset was coming from a dead 741 OP Amp. In with a new and now we had both channels working. Now we noticed that the balanced line output on one channel had DC. A silly 33uF capdensor was the evil doer. All the pots had a squirt of magic jollop to ensure nice operation. Reassemble and test. Very nice simple bit of kit
