I’m a little unclear on the placement of the Nano — the pin headers are 0.6" apart so you need 5 columns between them. But column 5 is occupied and column 12 is occluded by the ground jumper. I’m guessing you mean to use columns 6 and 12.
In DIYLC if you edit the DIP package you can specify 0.6" row spacing, which makes a somewhat less confusing (though still inaccurate) representation of the Nano:
I’m a bit puzzled by the trace cuts in columns 4 and 13 — most of them look superfluous (aside from row 4 in column 4 and rows 7, 15, 18 in column 13).
That uses a CA3080 which nobody has, but it can be replaced by half an LM13700 — but then you have to change the stripboard layout. So either way there’s layout work to do.
I recently bought 10 ca3080 chips from Aliexpress for € 7.55. I don’t know if they are any good. I bought them to make the simple dual VCA, but maybe I’ll build the diode ladder filter too.
I noticed that too, he doesn’t mention matching his diodes and says his works fine, so I was hoping that didn’t actually matter for his.
I have a half-finished transistor ladder filter because it’s so little fun to match the transistors, was hoping I could get a filter without bothering. I also don’t know how to match diodes, maybe it’s easier? Maybe this is all perfectionist voodoo and none of it matters very much for my purposes anyway? I have no idea.
I’ve also been curious how much of a difference it makes or if the matching thing is a holdover from when component tolerances weren’t as consistent
I matched transistors for three filters and I think only two out of all them had to go back in the bag, and they were still really close. the rest were dead on
Here’s a little breadboard version (though I think I was missing a wire in the photo - read the description that goes with it)
And a few posts following that one I talk more about my experience matching transistors.
Honestly - almost all of them that I tested where close enough to probably count as “matched” but since I put in the effort to measure them and am putting in the effort to build my own circuits I went for the “perfectionist voodoo” and used perfectly matched pairs since it was no extra effort once I had measured a hand full of transistors.
Does it make my filter work any better? I doubt it. But I do really like that ARP filter I used them on…It’s more “mellow” than my MS-20 and Steiner filters but that’s why I like it The Steiner will go absolutely bonkers with self-resonation and I’m actually considering tweaking it to make it a bit more predictable. The MS-20 is a great all around option and I’m glad I built it first. The ARP I’m dying to spend more time playing with…but just haven’t had time to actually use the synth much lately since almost all my spare time has been spent trying to tire out our new pup
From what I’ve read, just measure the forward voltage and match that. Many DVMs have a diode setting that will tell you the forward voltage, otherwise it’s a little breadboard circuit.
It’s my understanding that if you’ve got matched transistors, you can also turn them into matched diodes by tying the base directly to the collector. I’m planning on doing so when I get good at SMT soldering with a bunch of PMP4201Y or BC847BS matched pairs.
Update: This… “works”, but appears to cause a not insignificant amount of smoke to come out of one of the potentiometers. Won’t be trying this one again.
find on ebay i think.
The Steiner will go absolutely bonkers with self-resonation and I’m actually considering tweaking it to make it a bit more predictable. The MS-20 is a great all around option and I’m glad I built it first. The ARP I’m dying to spend more time playing with…but just haven’t had time to actually use the synth much lately since almost all my spare time has been spent trying to tire out our new pup 
