Re: Getting a more 303 sounding box..
I agree with most stuff you are saying and i think you can trust your ears.
I wouldnt swear on the metal film resistor thing. But tolerance does make units sound quite different.
The film/foil caps does the most difference.
The original psu is doing alot to the sound aswell. But this is prob not because of its construction but the fact that it feeds the opamp in the psu with ~15v insted of ~30v which is the case in the xox. The ml303 uses a 7815 to get a Similar vee voltage, you could prob make up something else.
Make sure that your 2sk30a(o) is authentic. Theres threads about this in the forum. And of course other transistors.
All the different npn transistors will sound different but i liked 536 and 945 the most.
In some places, the different measures of a transistor will give differences to the sound.
If you are experimenting with socketed transistors, dont forget to let everything settle for a while before you make your judgement.
And its a good thing to reference it with another machine, like a 606.
And about the el caps... ive tried xicons and panasonic fc. But i settled with che@p jamicons. Yes they are socketed in my vco , vca and vcf sektion.
Diodes seem to make small differencies, at least in the env and perhaps in the vco. Not sure but i think 1n4148 and 1ss133 sound different slightly or its the difference in voltage drop that made the differance. Id love to find some 1s2473 to try out.
The stuff about high hfe on q9-11 is not crucial key settings in my opinion.
The only transistor that i like a spec hfe is q18 which i like very low hfe so the bass doent dissapear to much when resonance is increased.
This dose of neardness will do for now :)
my machines kills fascists!