This or these projects will be on hold a while. Spending much of my time wth the Ukrainian refugees and brushing up my Russian. Besides a big box of FIRE … da da da! … FIRE!!! … da da da … arrived today - the Soundtronics MFOS MIDI Ultimate. There’s a thread about that one.
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Stored away in my bookshelf is the Concertmate MG-1 that I wanted to refurbish (remove the ugly gooey stuff and replace potentiometers and switches). Now I realise that the cheap 3-way switches are of the wrong kind. The fitted perfectly but my switches are WRONG WRONG WRONG!
New ones will be ordered from Syntaur ($15 a piece - 10 switches) …
Hope I haven’t ruined anything in my machine using wrong kinds. 
Else, having spent all Spring supporting refugees from Ukraine and now mrs K has arrived from the States. I still haven’t tested the MIDI Ultimate’s three VCOs and VCF …
Anyone got some hours I can buy? 
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I have totally forgotten what and when and WHY I wrote in this thread. Excuse me for spelling Errols as we enjoyed a buttle of whine on the balcony enjoying some Sonlight …
Anyway, my soldering and mounting of panels and modules did came to a slo-mo as the war … special operation (ugh!) started in Ukraine half a year ago and the last two months, my wife has been back in Sweden … So, nothing has been made apart from mounting some stuff in a plastic case for a NoiseToaster for my youngest grandchild.
I am leaving for Chicago and will visit KnobCon, a synth event just outside the city and will pick up a few PCBs for modules (mostly from Michael Barton).
However, when of some reason I ran into a YT video from the Italian synth museum and googled a Crumar synth I ended up at eBay and a SGS-ATES M110B1 chip - the heart of a few Italian synthesizers.
The chip contains a kbd encoder and a VCO and can be controller from external sources (LFO, octave switching …).
Some simple modules like a LFO, VCF, VCA and a pair of ADSR and - tada! - a small little synth!!
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In Chicago and waiting for UPS to deliver some PCBs for Bartons sequencer modules.
Also happened 
to buy the SGS M110 chip (the DCO used in some Italian synths).
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Problem problem problem.
I had ordered a Neutron-Sound quad VCA pcb and noticed that components are smd, maybe I saw that when ordered the pcb.
The problem now is that I have found schematics and something that looks like a bom, but immediately I see that the bom contains 4 quad opamps though there should be only three AND a 2164 vca chip.
Guess I will finish the great modules from Barton (4-knob sequencer, rhythm sequencer, 2xVCLFO, Clock Divider/multiplier and 1 song) and then tackle the quad VCA, which is in many aspects cool - you can’5 have too many VCAs.
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The rather minimalist build guide at Neutron Sound QVCA Build Guide.doc - Google Docs points to a BOM at Neutron BOMs working - Google Sheets but that apparently is the wrong BOM — at least it says it’s for the QAT quad attenuverter, which does look remarkably like the quad VCA but isn’t the same.
There’s this https://synthcube.com/cart/index.php?route=product/download/download&did=398 which lists four duals, two quads, and a 2164…
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Great, will check it up.
The bom I had found listed no VCA …
Still two more weeks in Chicago and returning home, I have the Barton modules to tackle …. and Soundtronics MIDI Ultimate. Sadly enuff, the Ultimate didn’t attract enuff interest, so it is discontinued.
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When looking at the bom in the docs suggested, I saw that Neutron listed components to a bunch of different modules,but each on a separate page on the worksheet.
Maybe there’s some light at the end of the tunnel.
Found a BOM, ordered the stuff from Mouser (about the TL072, I dunno - Mouser hinted ‘not longer produced’.
I just ordered components to two of the modules (pcbs) I picked up in USA and could have ordered som TL072s - smd.
Here’s some boards to populate this autumn (first to go - QVCA and VCLFO):
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Some varieties of TL072 are out of production but the TL072CP is certainly still available.
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I’ll see what happens. Everything is on hold until all parts are in stock.
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THREE HOURS LATER …
Damn, my project proceeds so slow, that even screing one piece of wood to my home-made cabinate a giant leap forward.
I still have some modules/boards from Elby-design to deal with (some wiring between pcb and panel), have to find a secret-holder (fuse-holder (*)) and busbars are expected to arrive from JLCPCB, maybe tomorrow.
But what is top priority is that I have some self-confidence and feel encoraged to do some smt soldering and try to solder the Neutron QVCA.
Just one nore however, the documentation is really poor. Found nothing on the Neutron webside and just by intense looking around the www, I got hold of a bom, a schematic and the bom uploaded to Mouser so I could do the shopping. It took me months to get the last pieces and now I notice there’s one position wrong but that will be fixed (**)
I have too much going on again …
(*) There was a great Swedish movie about Pablo Picasso, a comedy really. In one scene Picasso is to be electrocuted but nothing works so an electrician is called in. He talks about ‘secrets’, which is Swenglish for ‘säkringar’ (fuses).
(**) In two fifferent forums we have like a “Component Emergency”, where we ask around if someone has that missing cap, odd transistor whatever is missing instead of trying ordering the stuff from Mouser or Farnell. Most often we send stuff by mail and maybe asking for the postage. Will Mouser send one 1/8W resistor??
Enjoying real Swedish Aprilväder (April Weather - strong winds and wet snow 
) today.
My machine is slowly undergoing some work. Like starting to drill holes in the panels in order to screw them (rather permanently) to the babyblue rack. Got the busbars ready and also the PSU, but dunno where to fit it as I suddenly realise that even as I made me a bigger “cabinet”, I cannot fit all modules into it and I am thinking of remaking a few older panels that are a bit to wide.
Besides I am planning for a few more modules like a gate delay, LPG and a weird LFO.
Got a bunch of nice black screws from AliExpress that will get the modules screwed to the rack.
At least, slowly getting somewhere.
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