empress Reverb eurorack

The empress Reverb is one of the most expressive reverbs, IMHO 😀 So you know where I headed next? Yes, it’s getting to be a repetitive scenario for me, isn’t it? Original Manufacturer’s site is located HERE.

I like this pedal for the simple fact that is NOT the Eventide space. My conversion of that one is HERE. I find it most useful when you are wanting a delicate and diaphanous touch. I usually pair it up with the 4MS Spectral Multiband Resonator.

All circuitry is custom to each conversion and calibrated accordingly. There can be differences between pedals I find. Very unusual for a digital pedal. Conversions can be like that. Each one is unique and satisfying in its own way 😀

When does a eurorack synthesizer feel like an instrument?

I built this custom Korg MS-10 eurorack case four years ago. I knew I wanted to make a flexible and portable case that would hopefully give me enough room for a ‘super’ mono synth of sorts. During these last few years I was able to try out all sorts of modules and configurations. I would like to share some of my insights with you. The saying ‘Iv’e made a lot of special modifications’ goes without sayin’… but you just said it!?! Anyway…

I would say that at least two of those four years were spent in frustration. Some due to my unfamiliarity with the modules and some due to lack of time spent with the interface. What? you ask, it’s a keyboard! Yes and no. With eurorack you can have the keyboard be an odd shaped envelope or event generator or… The possibilities are literally endless. You are not encumbered with time honored traditions or traditional expectations. You build exactly what you want and more importantly, how you want to interface with it. So a keyboard doesn’t have to be just a keyboard 😀

Before he passed away I was lucky enough to correspond with Ray Wilson over at MFOS. He gave me great insight to the operation of his Keyboard controller and how to tune it and keep it tuned. I can’t recommend it enough. It has been the backbone of this converted Korg custom interface. That’s just the start…

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Quad Octoginta II

Since the CEM3340 chip was put back into production, and after seeing what a few other makers have built with them, I decided it was time for me to come up with my own take on this ‘tried and true’ chip! I looked over the various designs on using the CEM3340’s and settled on the Octoginta II.

Now that the VCO’s were sorted and I was able to purchase the DIY PCB’s, I needed to choose a wavefolder design. I like what Yusynth did with Haible’s wavefolder and went with his design here:


The YuSynth design required me to make my own PCB’s. This can be a laborious process if you have not done it before. But I have the process down to a science here in the lab, so I was able to get these made pretty quickly. Taste the Sodium Persulfate in the air, aahhhhh!

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Where to put the cables?

Now you have your DIY modules in your DIY rack, where do you put your cables? If you like the content here at MMM and would like to see more, please consider supporting us by buying a custom made basic eurorack cable stand with heavy base, or a custom cable holder that will fit a standard microphone stand. No crowd funding or Patreon commitment! These are ready to ship NOW!

SOLD OUT! Thank you for the support!

Running out of HP?

So you have a little coin left over from all of the DIY projects you have built? Now you need somewhere to put all of those new modules! Again you might be able to save some money if you build your own rack. All sorts of information you now have to be aware of. How much current are you going to use? Do you have lots of power hungry digital modules? I do 😀

Space is also a concern. You always want more HP, but at some point the case or rack just becomes too heavy to even move it around! I just finished this rack. It is 150HP wide, 5-3U and 2-1U. I believe this is as large as you can make it where one person can move it. Any bigger than this it will take two people to move it. I have worked this design for a while now. This is the third version of it. Here is a link to my earlier efforts and how it came to be.


I packed four PSU’s into this sucka’. So power specs are 16 Amps of +12V, 4 Amps of -12V, and 60 Amps of +5V! I have plenty of one off power crazy modules, so I really have need for this kind of current draw. One of the main trade offs for stuffing that kind of power into a smaller space is heat. You have to deal with that heat, so in this case I incorporated 2-120mm fans. Two fans for redundancy so one can fail and I can still operate on the cool. I kicked down the speed of the fans so they are not going full speed to cut down on the noise.

I added a custom CNC’d vented cover that allowed me to keep the streamlined look. I also added custom 1U power boards that have all of the various power connectors and even a specialized connector that I use for my own custom shit. The more custom stuff you make the more you have a tendency to start your own ideas and roll with your own standards. If you can customize your work space the more natural it feels for your specific work flow. Keep building smarter! 😀

When does DIY make sense?

At some point, unless you are rich, you will hit a financial wall when building a modular synth.  Sometimes the makers will have a DIY option and you might be able to curb some of those costs by building it yourself.  However, the DIY option can be a trap if you do not consider how deep and complex the project is.  I finished this custom set of World Cores and Control Cores and wanted to fill the remaining space with a custom set of utilities.  The original DIY project of the World Cores/Control Cores took me a year to finish.  That is a typical amount of time that it usually takes me to finish a fairly complex DIY project.  So that would be one of the first things I would advise, is to have plenty of patience and time when taking on a DIY project.

Next is passion!  After taking a year to finish the core builds I knew I wanted to build a couple of custom utility modules to accompany the core set.  It took me another six months to design and build those.  I have a love for the old 8 bit gaming systems, so it was easier to be patient as I trudged through those builds.  So, have plenty of ‘GO’ juice in the tank if you plan on finishing your build.

Plan on getting an education!  It’s one thing to gloss over a BOM and hit the big items on the list, but makers use all sorts of components when constructing their modules.  There is a good chance you will not immediately understand their choices.  That will immediately put you into research mode where you might have to delve in to understand how different micro processors are programmed or why you should solder the components in this order…   …and so on.  Expect to be stumped and expect to spend many hours scratching your head trying to figure this stuff out!

What I’m not done yet?  No, the last stage is the one that will ‘get’ most newbies.  Troubleshooting!  Here is where the rubber truly hits the road.  If you have been in modular for a few years, then you should already know what it is like to sit and troubleshoot ‘why’ something IS happening when it should not be and why something is NOT happening and it should.  It can be more of the same when you are close to the end of a DIY project.  Again, more patience and thinking is required at this point.  Sure you can rush over to this and that forum and beg for help and you might get some and get it to work, but if you are not that lucky you might have to go over all of your own work and have to figure out why your shiny new module is not working ‘properly’.  Keep your chin up…    …you are not alone 😀


Put a varied collection of modular wigglers together on a double vinyl record and you get FROM WIRES TO WAX. Has it been a minute since you turned on the turntable? Now you have the perfect excuse! I have to admit I even now find myself playing down the pitch control and holding it down on the slipmat, here and there. Not quite feeling to scratch just yet…    just holding, here and there.  More info here: CLICK HERE!

Akai MPCX Eurorack Cable Snake

This new Akai MPC has gotten me pretty wound up.  I am liking the new’er’,ish’ flow.  One thing I wanted to add pretty quickly on was a panel just for the CV/Gate outputs right in my main rack and ditch the longer patch cables.  So here is what I came up with.  I am hoping for a sort of standard too, so hackers please listen in.

Eight outputs and GND/0V mean a nine pin din is perfect for this cable snake. Simply use a standard 9 Pin DIN serial cable and if you decide to build one for yourself, just use the standard 9 pin numbering. Output pin 1-8 is pin one through eight on the serial connector and pin 9 is Gnd/0V.
This streamlines it into my setup nicely.  Without costing a bundle too.

The outside case mod is pretty easy to do and you don’t even have to detach all of the internal MPCX’s cables making it one of the quickest mods I have completed to a piece of hardware.

If you are interested in this mod, let me know and if there is enough interest I could do a run of kits. Back to patching… 😀

Strymon BigSky Eurorack Module

I was glad to see Strymon released their first eurorack module this year. Their Magneto module looks like a great entry and should fare well against others in that space. However after deeper analysis I find the module is lacking in a few areas. So, here I took their BigSky pedal and converted it over to a eurorack module. Having CV control over the parameters is a must and honestly, after using more CV, I could not go back to the original pedal again without them!  Plus, adding the MIDI in allows me to use the 60 Knobs & 60 Jacks to control it even further with CV! Link to the original manufacturers webpage HERE.

60 Knobs & 60 Jacks

Stop me if you have been here…          …You have been patching your modular synth for a while and then you get a thought of “I wish I could use this modulation source to control one of my other midi synth’s!”  Or what about a ‘deep’ guitar pedal that has a MIDI input and can be controlled via MIDI CC?  How about wanting to use many CV sources to control many MIDI CC’s or NRPN’s or even SysEx…   …with a stand alone box?  Or, how do I easily record all of these CV signals into my DAW so I can use them in MIDI tracks too?

Bastl released their 60 Knobs project last year and made it open source!  I immediately saw lots of potential and decided to see what I could come up with.  Their original project is located HERE.

Here are a couple of different configurations.

So, what did I add?   First is obvious, 60 jacks and the 60 pots are used as attenuators for the incoming CV signals.  Next was a small 9 tile 1U rack that can be used for whatever you want.  Here I have an oscilloscope, 4 LFOs from SYINSI (Each with three waveform outputs) and a couple of FSR’s from Pulplogic.  Of course you can patch up all of your existing modular gear too, but the on-board 1U devices are really helpful to get you started modulating quickly.  And if you know me, you know I love me some 1U gear!

How do you organize 60 knobs & 60 Jacks?  Custom printed/laminated, easily switchable vinyl templates!  What ever custom configuration and arrangement can be made and are attached to the top and bottom of the console via thin strips of Velcro.  Want to modulate all of the modulators in a virtual Matrix 12 with your eurorack gear?

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