Roman Sowa’s Synthpages

I’ve referenced Roman Sowa previously in the AD633 Ring modulator post however I’ve never posted about his past work. To start with, Roman has incredibly detailed build pages on his DIY analog synth projects here. If you dig in and check out the details on his modular build he includes photos, schematics, and technical details that are more than sufficient to guide you in your own build but not overly verbose and distracting. Take a look at his extraordinary hand-made modular.
Roman Sowa Modular

Sound Lab Ultimate Notes and Photos

I’ve finally completed the MFOS Sound Lab Ultimate and despite the scattered moments of irritation over the past 8 months all-in-all I think it’s come out great. I’ll assume folks reading this are familiar with DIY projects so I skip the detailed build notes and move directly to some key points that I think will help anyone who is considering building this project.

1. Read all the instructions before you start. This is a classic ‘rule-of-thumb’ and no matter how many times I ignore it, I am always reminded through costly errors that I should have followed it. For example, after spending many hours putting together my own parts list in Mouser for this project and bitching to myself that Ray Wilson should have a parts list link on his site I finally discovered that he in-fact does. Putting together a project parts list is easy when you only need 20 parts, but given the size of this project you don’t want to go through the painstaking process of doing it yourself.

2. If money permits, buy all 1% tolerance resistors. The design calls for some which are 1%, and some which do not need to be 1% but some of these are the same valued resistors. You don’t want to realize that you just soldered twenty 10k 5% resistors down which should have been the 10k 1% resistors. It’s an easy mistake to make. And I made it. Speaking of mistakes, double check your work before plugging in. notice anything peculiar in the photo below? I’m glad i spotted that error before plugging in the power supply.

3. Also, if money permits, spend some coin on good knobs. It makes a huge difference in the look and feel of the finished project. If you do use the knobs suggested in the project plans purchase extra. Many of mine arrived missing the mounting screw rendering them useless.

4. Also double check the shaft type of the knobs in the parts list. After receiving my order and setting up the control panel I realized half of them were D shaft and half were full round shaft. Mounting regular knobs on d-shaft pots makes the knobs rotate in an elliptical fashion and, although not critical, it’s a detail that just frustrates the hell out of me.

5. I struggled with what to do about an enclosure but I found this gem at hobby-lobby. It’s a painter’s box or rather “a wooden artist’s case”. Either way, it was 19.99 and I had a 40% off coupon so it was a score. The MFOS SLU fits perfectly into it with only slight modifications. The one pictured on the website looks way nicer than the one I picked up but I’m not sad. Hobby Lobby saved the day again with cheap pre-fabricated boxes for any project.

6. On the wiring side it’s a toss-up. On the one hand, solid core saves you a ton of time when tinning the ends of your wire and it’s easy to bend into shape. But when you have to run approximately 120 hook-up wires stranded may be the way to go for flexibilities sake. Your call. I’m happy w/ the solid core.

7. If you’re willing to risk it, I think it might be possible to forego the process of hand matching your transistors. I originally hand matched a couple dozen xxxx transistors and they needed it. However, I matched another handful of xxxxx and they were all within .002mV as per the specs. Perhaps it was a fluke, but building the circuit, and then actually testing the transistors took all night one evening.

Sneak-Thief’s DIY Experiments

Sneak-Thief’s DIY Experiments.

According to Sneak Thiefs website the following work in progress is,

…a mankato quadrature filter, 2 wogglebug #3’s, tellun neural agonizer (dual spring reverb), korg triple-resonator and a fonitronic 5-channel mixer.



An impressive array of modular gear @ Gingerbread Studios


RH84 Amp Rebuild

Awesome before and after rebuild of an RH84 Amp on this DIYAudio post.




Pass B1 Buffer Preamp sale DIY Audio

An great looking DIY pre-amp for sale via DIY Audio in this post.



Pass B1 Buffer Preamp sale. – diyAudio.

Pinky and Friends – SDIY.ORG has a number of great posters but by far the my favorite posts are by “Pinky & Friends“.  These are some the most unusual and creative DIY synths I’ve come across.  despite the simplicity of the site the most of the projects are well described and some have clear schematics.  Others however are just confusing.  Some of my favorites:

Turntable 110 (TT-110):  A DR-110 drum machine, $3 record player, and some ingenuity created a hardware based trigger for the drum machine.



Muffwiggler CGS Modules


A mannequin named Pinky.


Tube-based syth modeled after metasonix modules:


Muffwiggler DIY Forums

There’s absolutely too many great posts, pictures, and threads relating to DIY synthesis (and other topics) on Muffwiggler.  I’ve highlighted a couple posts below but if you want to kill a few hours or need inspiration while setting up your own work-space the Picture thread under Music Tech DIY kills it.

Take a look at two of my favorites

User Magman shows off his insane magazine and manual collection.  According to his post:

You are looking at complete or virtually complete collections of Elektor, ETI, Practical Electronics, Maplin Electronics, E&MM, Sound on Sound, Future Music, The Mix, Computer Music, 45 years worth of Wireless World and a large collection of Everyday Electronics, amongst others. By the way, this is less than half of my collection, which currently stands at over 9000 magazines and counting.



And Slaughterhousesam has a series of great pics of his rig and setup. this is just one of them and you can find the rest here. This one is fun for testing your gear-spotting skills.muffwiggler_slaughterhousesam_600

Vinnui’s DIY Modulation Bus

Vinnui has a concise site detailing the build of his modular.  He has put together some sharp looking modules and although he comments his wiring is a mess I think it looks exactly the way it should… made by hand, at home, with a soldering iron and a lot of patience.

Vinnui - YuSynth Dual VCO

It looks like it mostly consists of YuSynth modules though he also has a pretty cool idea for his own variation on the Moog Voyager’s modulation bus.  His expansion on the idea of a modulation bus is comprehensive and has about as many patching options as you could fit before it gets confusing or inconvenient compared to more traditional patch cables.  I could see something like this being very useful when you need to quickly dial something up without a handful of patch cables.

Vinnui - Modulation Bus

The layout consists of two buses, each sporting 12 possible sources, 12 destinations, and 12 shapers.  That’s a total of 1,728 patching combinations, per bus, with only the quick turn of three dials.  Purists may not like the rotary switch patching of modulators but I think its a brilliantly simple way to manage a large number of patching capabilities in an easy to remember/recall format.

Groovewatt Tube RIAA Phono Preamp

I love the simplicity and classic styling of this DIY vacuum-tube, RIAA EQ curve, phono pre-amp. Bruce Heran via the DIY Audio Projects forums offers up exceptional build notes, pictures, and schematics of the build here. Admittedly I don’t know a thing about valve pre-amps and amps so I can only really comment on how much I like how it looks.

DIY Audio Projects – Hi-Fi Blog for DIY Audiophiles: Groovewatt Tube RIAA Phono Preamp.

Workshop Osc Machine (W.O.M.)

An excellent thread detailing a build of the ‘Workshop Oscillator Machine’ (WOM) via Bugbrand. The WOM is a tone generator/oscillator designed around an NXP Hex Inverter and an NXP Hex Schmitt Trigger. What i particularly like about this kit is that it’s designed with the intent of usage in workshop and educational events and includes all required parts. Although i have not personally built this kit, I suspect by looking at it that it’s a nice balance between ease of build and functionality. And if you were so inclined Bugbrand includes the schematic on their site so you could always wire one up on your own, sans pcb, and see what happens.

WOM - Bugbrand