Moog Filter questions

Design Concepts
1

I am starting to work on a Moog Style filter in a size and layout similar to Seppoman’s SSM PCB. My thoughts were to be pin compatible as far as headers. I am almost finished with my schematic and working on the layout. And will gladly make the schematic and PCB files available.

I am using a LM13700 as a VCA to have voltage controllable Resonance.

I was using Rick Jansen’s VCF schematic with some changes. In Rick Jansen’s schematic for the VCF, he uses some op amps for buffers and a difference amp. I have decided I would use discrete transistors. I’ll post pictures as I go. I  am hoping to to a breadboard of the  PCB in about a week or two.

Four quick questions:

Is there a PCB house that does cheap one off double sided boards?

Also is there a standard thickness such as 32mil thick that is more convenient to use?

How is Eagle’s autorouter?

I have also seen a few different values for the VCF caps. is  there a preferred value?

Any help would be appreciated.

2

Uh oh the autorouter question again.

The consensus on autoroute is somewhere between “it’s evil never use it at all whatsoever”, and “it’s evil, only use it to get a hint (after which you will rip it all up and lay out by hand), and only if you are fully aware of it’s shortcomings so that you can tell when it is doing a bad job and accordingly use it as a guideline for what-not-to-do. (something it’s far better at doing, than giving guidelines on what-to-do)”

The short version is, don’t autoroute.

3

yeah, for a good laugh, I hit auto route…  ick!! Thank God I saved it beforehand.