There’s no harm in an income from a hobby. Almost all of my 60+ guitar collection was paid for by gigging or flipping damaged musical kit. All of my luthier woodworking tools were paid for by upcycling and adapting dross from charity shops and local scrapyards.
Btw, i remember you had some hammond bits - i keep seeing hammond amp to combo conversions going for ‘silly big money’. A project like that would keep you in jack sockets for a while 
Version 2 of my Moritz Klein VCO, built on a slightly larger board. I’m going over my layout to verify all the connections and parts are present, and next is to verify it again against the schematic. It’s taking longer than I’d like, but hopefully this one will work properly. I’ve still got a working proto on the breadboard for troubleshooting. I’m trying to be extra super careful–if I burn up any more chips I’m going to need to place another parts order…
Looks much better than V1.0!!!
Thanks! But you haven’t seen the back… LOL
I find its good practice to test as you go when building on stripboard. Primarily to check for often hard to see shorts between tracks. The first time you power up do so without any expensive components in place and if available using a current limited power supply. When you are reasonably sure there are no shorts then test with all components in place again preferably with a current limited power supply.
It’s kind of a breadboard stripboard, not regular, but I am definitely jumping a lot of pads and traces. I already found one place where I put a wire in the wrong hole. I’m going to meter everything for continuity/shorts first before I give it power. And yeah, it’ll either be getting power from my module tester or my bench PSU.
I wasn’t sure of the best way to test this on the board as I built it, but I re-drew my layout and triple checked that against the schematic. I guess we will see!
Absolutely do power up with no chips socketed first — if nothing burns up, check the voltages on the socket pins, and then and only then power off and insert chips.
And before all that, before power up, check continuity from power header (or diodes or fuses or 10R resistors if used) to IC power pins, and lack of shorts between power rails or from rails to output pins!
Did a demo of a few patches of my recent Polykit DCO build.
Shows a few different sounds you can get using some of the different features.
OoooOooOooOOooo. I’ve been meaning to pick up one of these kits and have a go at surface mount stuff.
Well, I’ve at last completed my modified Turing Machine LPG/MIX module with switchable Pulses/Gates connections - much later than I’d hoped:
The only problem was that the LPG output was so short that it really wasn’t possible to hear the filtering as the sound faded to silence too quickly, although it was clearly happening on the scope. I was about to write it off as inevitable given the speed of my home-made (ultrabright red LED / 5528 LDR) vactrols. Then it struck me that the signal going into the output buffers (U2A, U2B) is via a potential divider -
So if anyone is using home-made vactrols in either a Vactrol Mix or a Worng TM-LPG-X type device, do try different values for these components - they have a profound effect on the output. Anyone building in a larger format (I’m Eurorack) could add a pot to adjust the decay time for Vactrol Mix output and a switch to have a choice of capacitors for LPG output. Happy experimenting!
Do you have any sound snippets available that illustrate the problem before and after you solved it? I’d love to hear those.
Here’s a quick example. The left channel (long notes) is LPG mode with a 10nF capacitor to lengthen the decay time, right (short notes) is the LPG as originally built with a 220nF capacitor as specified in the Worng schematic.
So the LDR response time depends on the impedance it’s in series with? I didn’t know that. Both on and off times or just one?
Just for clarification, changing R11 doesn’t change the LPG behavior — right? Isn’t it switched out?
I don’t think it’s the response time changing, it’s rather that with a larger resistance (or reactance for an LPG) to ground you sample more of the LDR relaxation curve before the signal becomes inaudible. The on time is still very rapid.
R11 is only relevant for Vactrol Mix mode, it’s switched out in LPG mode. It can be nice to have the more bell-like decay for the mixer as well so I decided to keep that in this module - I already have a straight Vactrol Mix with a fast response. The ideal arrangement giving maximum flexibility would be to use a dual pot to control the mix response time and have maybe 3 or 4 switch-selectable capacitors to vary the response in LPG mode. There’s no room to fit them on my eurorack panel, though I could add another panel with just those controls - perhaps a step too far!
Oh right… to close the gate by getting down to say 20 Hz with a 220 nF cap requires the vactrol to reach only about 30k. With a 10 nF cap it needs to get to about 660k.
I’m drawing up a Kosmo version. Should have room for another pot and a switch.
I’ve built one power display module (just a couple LEDs and test points) for each of my bus boards, but I decided to do a new version to replace at least one of them. This one adds a power header on the front panel — to make it easier to power modules that are being tested or undergoing troubleshooting. (And when not in use, it’ll have a spare IDC connector covering it!)
Rather than having a little PCB behind the panel, the panel is the PCB. The “inside” power header is surface mount as are the LED resistors. The LEDs are “through hole” but I bent the leads to solder them to surface pads. The “outside” power header is through hole.
Snap! - well almost…
Im curious about that big yellow box behind the panel, what is it?
Only a guess… solder fume “extractor” ?
