As cheap as I can, the old geezers modular synth

Hello all,

I’d started this in another place, but then as you do I found the LMNC pages with verified stripboard layouts and lots and lots of useful links.

I thought I would make a new beginning here in this forum. I found the modular music of Hélène Vogelsinger, no keyboard! I’d made a synth in the 80’s with a keyboard couldn’t play it gave it to a band.

Well I thought my next project is going to be a no keyboard modular synth. I will use it make sound tracks for my videos, which will feature my DAZ3D dancer K.Thorn, hence the AV

I started with a box and bought some plywood and made some power rails. I’m a tight old geezer I can solder and I see no need to buy sockets and connectors.

It’s 600 x 350 and 100 deep, it will take 3U (128) panels, I’ve bought some 1.5 blank aluminium panels of the right height and 10HP wide (50) any others I can cut myself.

I wanted to find a very simple way to mount the modules. The centre cross member has a couple of pieces of 2mm grey card glued on to make a 2mm deep slot either side which is 3mm from the edge of the plywood. The card has had several coats of Shellac this soaks into the card giving it a strong and wood like feel.

All I needed then was one screw and a washer at the other end, an M2 one screwed into a 1.5mm hole and cutting its own thread, the result is a very firm fixing preventing any lateral movement.

The alloy panels I’ve got are 1.5mm thick and when I print the fascia card and glue it to a panel it will be a tight fit in the slot preventing the panel from moving up when patch cables are removed.

The depth of the centre and lower crossmembers allow for the use of Eddy Bergman’s 65 x 145mm stripboards.

I will be buying some PCB’s and ready programmed PIC chips from Michael Barton his PCB boards have 5v regulators designed in so I don’t need a separate 5v supply. It would be easy to make one to fit in the case though it’s only three components.



A 10 pin box header and matching IDC connector will cost you $0.34 at Tayda. A bus board’s worth costs less than a burger, and having to use a soldering iron every time you want to change something is going to get old real fast.

I like saving money too, but only to a point.



Many thanks for your kind comment good of you to do so.
That is a very good price living in the UK as I do I’d not heard of the supplier you mention.

I feel it my duty to explain fully why I used the method I chose. My initial researches revealed that PCB’s were in line and backed up to the panels, hence the reason for shallow boxes.

But I thought what if, as one does, the PCB’s or stripboards are at a right angle to the panels and what depth would they be, at the time unknown. Further research revealed Eddy’s site and his stripboard layouts and looking at other sites I found other stripboard layouts and others where one could download single sided PCB’s for home etching, some of them 85mm deep.

The reason I chose the rails and sleepers is this depth, had I used connectors and made a strip of them sods law would come into play and foul a board. I kept the height of my rails to 7mm using 2mm grey card and Code 75 rail.

I don’t mind soldering stuff in the least, at the panel end there will be some Q/R connectors to release the panels.

I do hope this goes some way to your understanding of my motives and may I thank you for the opportunity to do so.



Love it! The power rails are simple and elegant.
It’s your project, do it your way. Please!
This is how I used to breadboard back in the 80’s, fixing bare lines and feeding off them.
Modern 10 pin and molex connectors are very useful when you want to swap out a build but none of it is mandatory.
A great deal of my builds have been made with salvaged parts, recovered wire and hell if you can make something for nothing that’s not tight that is genius.
I have guitars made of door frames and kitchen drawers, flutes and whistles made of salvaged pipe, my first distortion pedal was simply a switch from an old hoover to turn off the cooling fan on an old valve amp. You use what you have and know.

As for the sizes and fit for the PCBs play it by ear and maybe you’ll have to finagle as you go… All part of the fun. No rules to say how you mount the PCBs, they don’t have to be fixed to the panel at all if you like.
You could also make many of the modules as dead bug freeform (no pcb at all! - folks, who is that maker with the modular made of tins?)

While many of us draw inspiration and motivation from Sam (@lookmumnocomputer ) and this brilliant community here, only some of us build in Kosmo format or eurorack, many build stand alone instruments and synths/fx.

Enough of my waffle.

So crack on, keep us posted and sing out if you need help with anything. I look forward to seeing more.


MFOS’s Ray Wilson did it this way, so I guess it is good enough :slight_smile:


@CxC Welcome to the forum :slight_smile:

Maybe Juanito Moore

ex :


Hello Farabide,

Many thanks for your lovely message very good of you to explain at length. I agree with all you say. I’ve always made stuff myself and find that I come up with ways to do things that I’d not thought of at the start of a project. That I think is as much fun as the actual making or assembling or whatever depending on the pastime.

Gyles Brandreth lost his seat in Parliament some years and coupled with some personal disasters he felt very down. He went to see Psychiatrist Dr Anthony Clare the presenter of BBC R4’s “In the Psychiatrist’s Chair” programme. And the good doctor said, “You must have a passion in your life, it does not matter what it is”, two of the most important phrases ever uttered.

Many interests have the side effect that someone my age can talk directly with no age barrier to much younger people and that is a wonderful part of anyone’s passion.

Hello Eric,

I made Ray’s WSG and Rob Hordijk’s Benjolin a few years ago and intend to make some of Ray’s simpler circuits using his single sided PCB diagrams.

Hello Dud,

Many thanks for your welcome. That project you linked to is amazing thanks a lot for that :slight_smile:

Thinking of point to point wiring I made a 3886 chip amp without a board, so few were the components a board was superfluous, very satisfying way of doing things.

My best wishes to you all, cheers


Maybe Wilson was so good, he never needed to repeatedly connect and disconnect a module for troubleshooting and repair purposes. I’m not that good.


Hello all,

My power supply

The circuit is from Eddy’s site I used a 12v 30VA toroid I had in my odds box, it will probably not be powerful enough for the box when filled with modules.

Looking at the mammoth projects one sees on this site I’m probably going to make another box at half the width. I have another toroid it’s 12v 60VA, I can use this to make another supply and bypass some 7812/7912 1.5 Amp regulators with TIP41c/TIP42c.

Incidentally the toroids I bought as a job lot have thermal cutouts, or maybe they all do I’m not sure.

The connector you can see is a 3 pole 12mm avionic one I used some thin 3 core mains cable for the output. The outer shield would not go into the clamp so I covered the inner cables with some heat shrink plastic.

The Red LED indicates the positive voltage and the blue one the negative.




The Thomas Henry 555 VCO

When I started looking at Eddy’s site I thought this VCO was the bees knees. I did look at others and eventually found TH’s own words reporting that the 555 was the best VCO he’d ever designed.

I downloaded all Eddy’s stuff about it from his site and read and looked at it all. I started to make one on the the stripboard eddy uses, only to find that mine was 55 holes instead of the 56 holes on Eddy’s one. No problem though just move the right hand stuff back one row.

Which led me to thinking ahhhh! Photoshop to the rescue and a way of making it easier to build. I got a new board and did this

The holes are at the maximum only 0.5mm out as you can see from the trial pin holes. I stuck the pic on with one of those glue stick things after going over the top of the board with fine emery paper.

It turned something I found really complex to something else a lot easier to manage I’ve got about 1/2 way across it now.



I use wine boxes to build my synth.
I’m using meanwell RT-65b power supplies and I build power-busboards myself with stripboard.
All equipments come from aliexpress or eBay (rails, screw, wire, 16pin connectors, etc…)

Really cheapy modular system ! (just be safe with the power supply part!)




Hooray! What an amazing sight! Bravo!


You’ve worked very hard on that fair play to you :slight_smile:



The cases start to pile up :grin:
great job !!!

1 Like

Hello all,

Very well done indeed @saint_et_moudulard lovely to see a finished item, gives me the encouragement to continue my efforts

Sadly my stripboard idea failed, couldn’t find a mistake on the back of the board, put it on one side, have a go later.

I started looking for single sided PCB’s and found the Thomas Henry XR2206, the VCO-1 and the X-4046 osillators. No sign of a single sided board for the TH VCO-555 though sadly, ah well, there we go.

Then as you do I realised that my box was not deep enough to take the boards some of which are about 85mm wide, so I had to make my box taller by 35mm.

Then I bought some photo etch boards, some developer and etcher and found a used UV light box on eBay.

I made a test strip and did six one minute exposures using this little arrangement. I used two ‘prints’ in register on cheapo OHP film.

And got this

I think 2 mins exposure will be ideal. It took 5 Mins in the developer and 45 Mins in the Ferric Chloride.



Thank you,

Really Nice work !! How do you print your board ?? It is easy ?
Really curious to learning your method step by step…

My case is too much deep because my circuits are really messy and large ^^

Keep it up; you are on the way to success!! Don’t worry, after having built your first case you will chain several of them on the same model!!

Have fun !!


Hello @saint_et_moudulard

Thanks for your nice comments good of you.

May I ask you to install Photoshop CS6, various other software offerings that claim to be as good are not!

I will do a screencast of the worst case scenario, wrong size PCB when downloaded and how to alter the tracks. This is the sort of thing that Ps excels at simply and quickly.

I’ll do it tonight and post it here tomorrow.



Hello @saint_et_moudulard,

I did the screencast and have put it up on YT

I do hope you find it useful.



Hello all,

I used a travel Iron to press this down and it worked very well indeed.

The etching which with lots of copper to get rid of took 3+ hours in the FC, this one took just an hour in cold etcher and no swirling it about.

It’s on SRBP stuff I found that I can hold it up to the light to see if it’s etched properly. There are few black splodges in it I’ll probably have to join those with some solder.

To say that I’m pleased after 5 or 6 weeks of various failures is putting it mildly, ‘knock me down wiv a fevver’



Thank you a lot, really Nice work !
I go look at this when I have more time! :slight_smile: (excited !!)