17 January 2010

MFOS Stereo Mixer (Part 1)

This weekend I started on finishing a new project. It is a stereo mixer. I used a PCB that I bought from Music From Outer Space (MFOS) designed by Ray Wilson. I designed a MOTM style front panel myself for this module that I had produced by Schaeffer. It is quite a nice mixer with 4 mono inputs, 2 stereo inputs, 2 stereo send and returns for SFX integration and it also has a build in headphone amplifier. On all mono channels you have a level potmeter, a pan potmeter and 2 send potmeters. I used Alpha potmeters for the mono channels but had some trouble sourcing stereo potmeters. But I found two sets of 6 and will see which ones are best later on.

As usual I started with the inter component wiring on the back of the front panel. All components have a ground connection as you can see by the black wiring runing through everywhere. And then some wires from the input jacks to the potmeters. Then I started attaching all the wiring to the PCB. As you can see there is quite some wires actually. It was quite a challenge to organize them a bit also because they come from everywhere on the PCB. I also managed to solder on a screw terminal for the power like I did for my Yusynth modules. The only thing that annoys be a bit is that the elco's on the bottom are not all straight on. But this was quite a tight fit. Ah well nobody will see it eventually, but I like to have things neat and tidy.

And here is the finished module from the back. It is not always easy to solder the wires on the bottom layer of the dual stereo potmeters. The soldering lugs are quite difficult to reach sometimes. But I managed to get everything in place. Ray has quite a nice wiring scheme on his website that I followed. Sometimes the naming of the inputs and outputs on the PCB are a bit confusing. Well there is quite some as well as you can see. Well I think I managed to organize the wiring quite OK. Actually I didn't even expect that up front ;)

And here is a shot of the front of the module. I seem to have made a little mistake somewhere with the design. I had to adjust the 4 pot bracket I used because the potmeters where not all in the perfect spot. But I don't see it from this shot do you? Looks alright to me, but then again I don't really have an eye for these sort of things. If you like to use this front panel design, just send me an E-mal and I'll give you the .fpd file for Front Panel Express. OK now it is time for some testing. I will do that tonight after dinner. For now I'm going to take a little break :)


Mary-Cat said...

Hi Michel,
Wow, this looks like it was a handful to put together! It came out well though, I see. The front looks fine to me. In quilting we have what is called a "Galloping Horse" mistake; if you can't see it from a galloping horse, then it isn't a mistake. ;-) Well done Michel!

Synth.nl said...

Haha. Galoping horse. That is a good one. I'll remember that :)

Hannah said...

Hey do you remember about how much you spent on parts for this? I'm considering buying it but i'm a college student so money isn't the best right now.

Synth.nl said...

I'm sorry I don't remember. I think the potmeters and front panel were the most expensive.