Moogerfooger schematics! Here they are!

[fig]

Unfortunately the MF Drive schematic isn't on that page. I haven't had any luck finding that one, but would be very interested in checking it out.

I haven't verified this yet but I started a thread @ FSB that has the boards and the traces outlined.  Here is the schematic I came up with and the link to the thread.

https://www.freestompboxes.org/viewtopic.php?t=31250

Awesome! And, really, that schematic drawing is like a work of art. Honestly - it's beautiful work.

An aside - I am totally going to acquire an MF-104m someday. They are quite spendy now but I want to figure out how to afford it, haha.

You could DIY one. I hear it's all the rage. 

[matmosphere]

The schematic for the mf104 is floating around online. It's something like 12 pages long. You could probably DIY it but it would be a lot of work.

[madbean]

Oh I have it (the schematic). I'm not insane enough to DIY something like that.

[benny_profane]

Oh I have it (the schematic). I'm not insane enough to DIY something like that.

Not even with four layers?

[fig]

Definitely beyond my attention span (for starters).

Wow, they ARE pricey! 

[Chillums]

Thanks Bean and Scruff... It still bugs me that the LED even works the way they have it hooked up.  I looked at it for hours thinking I missed something.  The cathode is being pulled up with R19 and the 2n7003 pulls it to ground I suppose....

[Scruffie]

The schematic for the mf104 is floating around online. It's something like 12 pages long. You could probably DIY it but it would be a lot of work.

Only the first 2 pages are relevant, it doesn't look too bad really.

That gutshot earlier in the thread is for the 105 or 108.

(mod edit) link since it's not loading: http://www.analoguediehard.com/studio/effects/moog_moogerfoogers/moog_mf-gutz.jpg

[madbean]

Couple interesting things I've observed about the MF-104 delay schem (assuming I've read it correctly b/c it is difficult to follow):

The pre/de-emphasis filters are outside the compander loop. IOW, it looks like only the BBDs are in the loop which is counter to how most analog delays work.

From the datasheet, the SA572 appears to be a slightly "beefed up" SA571/NE570. It has separate attack and recovery 'programmable' pins which I don't think you can do with the NE570. It also looks like the 572 is designed with external op-amp input/output in mind rather than the internal 741 style of the NE570 if I'm following correctly. On the MF104 schem, there is a TL072 handling the input/output part with its bias being taken directly from the THD_TRIM output pin. This is something I've heard of before so it's neat to see it used here.

Lastly, the use of switched filtering looks very familiar after pouring through the StarChambre design! My brian, err, brain is firing with ideas from all this.

[Scruffie]

Ignoring the blinky light controls on Pg1 make it easier to read, the rest on that page is just expression control and mixing for the various controls.

It's late but I can't actually see any emphasis network going on?

The 4016 looks like it's just switching between 2 sets of filters for short/long mode.

Check out the vintage EHX 16 second delay schematic for a TL082 being used with a NE571 and yeah, you've got the 572, the deluxe model with full control and an external op amp.

[madbean]

I don't know if I'm insane enough to try and clone it, but I am at least insane enough to re-draw the MF104 schem. Learning a lot about how it works. The main thing is keeping track of the off-board connections but I have a strategy to get that in order.

There is a small breakout board that contains 3-5 MN3008 depending on the model, I guess. That's the short delay, if I'm reading it correctly. Then the long delay adds the two MN3005 in series. I think a practical approach would be just use 3 MN3005 and switch in the latter two for the long delay setting. That gets you 750-800ms I think.

Anyway, Berhinger is cloning the Moogfoogers apparently.

It's late but I can't actually see any emphasis network going on?

The 4016 looks like it's just switching between 2 sets of filters for short/long mode.

Yes, that is exactly it. Another interesting note is they only use a single trimmer to set the bias of all the BBD. Also, the clock is not buffered at all and it runs at least 5 of them. With just a little bit extra work, one could copy the DCEcho clock buffering and have a "hi-fi" setting maybe!

[jimilee]

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