Anyone Have A Layout Diagram For Sovtek MIG-50?

[Jecarroll7]

I found the schematics but haven't seen the Layout yet. Appreciate any help with this.

[soundguruman]

You might be able to get it from new sensor.
It's usually the potentiometers and power supply diodes that fail.
Other than that, it could be a fairly decent amp. Very clean.
I have fixed them and after fixing the above, they keep going.
Please note that when replacing Russian diodes, they are marked opposite of other diodes. The anode is defined by the marking, instead of the usual cathode.

[Jecarroll7]

Hey SGM, thanks again for your help on the Prosonic. I learned a lot about that amp getting it running.

I haven't plugged the MIG in yet but I'm told its the pots. Have seen a number of suggestions for replacing with CTS and running wires to PCB?

Thanks for the New Sensor suggestion, sent Tech Support a request.

[soundguruman]

If you are going to use PC mount pots, you should use 1/4 inch shaft pots with a threaded bushing. Some are available from Bournes, but you may have to special order them.
http://www.bourns.com/proaudio/pamm.aspx
The original pots had no bushing (like a crate amp), and that's why they break so easily. These were only supported by the solder connections. Pathetic.
If you are going to install flying leads, and retrofit professional controls, I have been using Precision Canada audio taper, which are about $10 each, but they are really nice stainless steel, and much harder to break.
http://www.amazon.com/PEC-Guitar-Amp...0448656&sr=8-1
Retrofitting takes a bit of work. The front panel needs to be drilled out slightly to make the holes bigger. The circuit board mounting rail needs to be shimmed, and the circuit board mounting insulators need to be slightly lower.
Retrofitting is a job for a person with tools and plenty of patience, I'm not kidding.
After all that work you get a reward. The precision pots are perfectly smooth all the way from "0" to "10" and the rotational travel is also increased by 20 degrees. These are the best potentiometers out there. They are so much better than consumer grade controls, it's like night and day.
The old knobs are 1/8" shafts with push on knobs, no good at all for rock and roll.
Stainless steel pots: you need new set screw type knobs. I have been using original fender pointer knobs (like the ones on the hot rod deluxe). The setscrew MUST be steel, NOT brass. Brass will strip the threads. Almost ALL aftermarket control knobs are brass set screws, so be aware of that. This is why I use the good fender knobs with steel inserts.
Wire: I highly recommend that you use teflon coated, stranded wire. As you can see, a couple of the controls are right up against the power supply capacitors, or about 1/8" away. I fill the gap with RTV cement, and I epoxy the new wires to the board, to act as a strain relief.
Lots of effort, but boy what a difference! It's like a new amplifier when you are done.
The MIG also has plenty of possibilities for tweaking the gain, so that the amp will grind properly. It's actually a pretty good amp when you get passed the controls.