Hello

as Julian already described, if you would not allow digital functions in
a synth you would have a sawtooth VCO with a Filter and a VCA. Nothing
else. The pulse wave is already a digital conversion from the saw-core
of the VCO.

I think you want to avoid A/D-D/A constructs in the audio signal path.
This may make sense. But nearly all control modules (even envelopes,
LFOs, ...) have some kind of digital function. So I suggest you should
exclude this type of modules from your yonstraint.

In consequence: the A-149-series would be allowed for you too.

Florian