Fostex MN50 compressor ideas

[Yazoo]

I use the Gimp (Gnu Image Manipulation Program) which is open source freeware to trace over photos to create pcbs. I've just used it to do the Echo/Reverb board for the Rockman X100 and it works well.

By the way, thanks for this project. I'm going to do this next - I have to have something to do while the quarantine lasts - it's either this or gardening!

[FUZZZZzzzz]

haha.. I only have a balcony with some pot plants. I will give GIMP a try. thanks!

let me know how you get on!

btw. do you just draw paths with gimp?

[Yazoo]

I just create a new layer and paint over the traces with a black paint brush. I resample the picture to 300 DPI then resize by measuring the distance between the IC pins and using this to get a resize ratio. The accuracy is good.

[FUZZZZzzzz]

All I can say is that it does work. Gives it a kind of Old School image as well. This is board 2. Just to try it out. Still need to resize.

[snk]

Nice.
Did you decide to go the PCB way, and leave out the veroboard layout ?
Or do you plan do do both ?

[rankot]

All I can say is that it does work. Gives it a kind of Old School image as well. This is board 2. Just to try it out. Still need to resize.

I suggest you to draw lines using brush and click-> Shift+click method (in Photoshop). Then your lines will be straight. Also, you can make a brush size for pads and simply click to make pads.

[FUZZZZzzzz]

The vero that I made earlier  is still untested. PCB is smaller, easier and a vero will be very crowded and very easy to mess up. I do also have an etching tank and enough boards and materials to work with. I don't know yet.  Maybe both.

[FUZZZZzzzz]

All I can say is that it does work. Gives it a kind of Old School image as well. This is board 2. Just to try it out. Still need to resize.

I suggest you to draw lines using brush and click-> Shift+click method (in Photoshop). Then your lines will be straight. Also, you can make a brush size for pads and simply click to make pads.

Thanks for the advice! I was looking at Photoshop before. Straight lines and pads are probably easier for bigger boards as well. Thats the reason I was trying the smallest board first lets see how it goes.

[snk]

You may try Serif Affinity and Designer. It's cheaper than Photoshop, and works fine.
I also think that it is free to use during the quarantine.

[duck_arse]

All I can say is that it does work. Gives it a kind of Old School image as well. This is board 2. Just to try it out. Still need to resize.

in gimp - if you copy your base layer, then use the select-by-colour tool, then 'delete' the selection result, you will be left with, maybe, just the copper or just the fibreglass, depends what you select. you can also invert what you've selected before deleting. many ways to kill a kat.

[kizzer]

Thread bump.

I saw a video on this compressor and it looked like a fun little unit. Thanks for the pictures of the unit as they helped me hunt down a few inaccuracies with the schematic. With a little help on the GroupDIY forum I managed to come up with a layout for a dual (line level only) mn50 compressor. It has an added Attack knob and I have inverted the Release knob, just flip the connections to revert it to stock.

[snk]

Thank you, Kizzer!

[antonis]

Are you sure abouth D4 Zener diode value..??
(I can't see the reason for pedal working at 9V when fed from battery but less than 7V when fed from external source..)

[anotherjim]

Is there a better value Zener for the DC input? But if it were me, I'd make it standard centre negative 9v DC input anyway.

Could a pot (Threshold?) be added feeding R15 so you can adjust the output operating level?

Can the 2v Zener be x3 1N4148? I don't have any 2v Zeners.

[kizzer]

Are you sure abouth D4 Zener diode value..??
(I can't see the reason for pedal working at 9V when fed from battery but less than 7V when fed from external source..)

I just went with the schematic for D4's value.

You could take the power elements off the board and save yourself 4 rows and build a power daughter board and experiment.

[antonis]

You could take the power elements off the board and save yourself 4 rows and build a power daughter board and experiment.

I'd prefer to place a 9V1 Zener (or better 3V9 + 5V6) in place of D4..