Minimoog Clone Help Testing and Tunning

[roboDNA]

UPDATE: This issue has been resolved! My system is now tuned


I built a Minimoog Clone and am working on testing and tuning it. ( I used the MME kit for now to learn )

My main issue is the main audio output seems to be missing all the high end. The main audio output wave is a sine no matter if I have the source set to triangle, saw, shark, or square... the VCF filter seems to be turning them all into a sine wave.

I have connected a scope and see all the different wave shapes looking good just before the Mixer block. I'm using a saw wave for testing. The saw wave seems to get a bit noise once the signal enters the MIXER block, after it has passed the 330ohm resistor. I'm not sure if the saw wave should look this noisy on my scope so I"m looking for a second opinion.


Here is what the OSC1 SAW looks like just before it enters the MIXER block:

Here is what the OSC1 SAW looks like just after it enters the MIXER block: ( just after the 330ohm resistor )

My saw, and any other wave shape I pass through the VCF block turn into a sine wave. I suspect my VCF build is faulty and would like to know how I could test it. Are there test points with known values I can check or should I start replacing components?

I'm include some screenshots of my scope. It sounds like I"m missing all the high end, confirming the sine wave I see on my scope when I connect it to the main audio out.

Here is the saw wave before the MIXER block ( yellow line ), and the after the SAW exists the VCF filter block ( blue line ):

Thanks!

[VCO]

Very impressive your background must be in electronics and engineering. Was it an expensive build? Are you going to post any video and audio of what it looks like or sounds like? Do you have a midi keyboard hooked up to it?
Take care

[roboDNA]

Very impressive your background must be in electronics and engineering. Was it an expensive build? Are you going to post any video and audio of what it looks like or sounds like? Do you have a midi keyboard hooked up to it?
Take care

I did end up working out the issues with my first Minimoog build. I used the MME boards but am now working on a second build with my own boards. I'm not sure how much it cost but I'm guessing above $1000. I do plan on adding MIDI but as a separate MIDI->CV module. I'll have a page up for my build and will post it here when it's ready to go.