Zener Synth Distortion: alive and kicking (with sound file and scope photos)

Hello Again.  This time closing out the "Zener Synth Distortion" Project.

You can read Part I, how I stumbled upon this circuit, here.

They are up and running,  panels Lazertran'd, ready to go.

Here are the two zener distortion units in my rack:

This is a super simple build, almost no parts!

How does it sound?  you be the judge! I have uploaded a demo sound file on Soundcloud.

I tried to give the most objective before/after demo of the 2 modules as I could. No reverb, no filters, no echo etc.  How boring right?

 Here is how I patched my fully DIY home grown works most of the time modular synthesizer to get the demo sound going:

On the demo the first few sounds are from the "Zener" design:

"Zener" provides in your face, loud, crunchy distortion and greatly emphasizes beat frequencies.  maybe a bit much?

The rest of the demo (the last 3:30 or so worth) is "Son of Zener", a lot more subtle.

Shorts anyone? On "ElectroMusic" forum there …

Thomas Henry 13700 based VCO: All hail the mighty Henry!

How much have I learned from Thomas Henry's books?  Well it's all relative I guess but for me,  a lot!  I went from zero knowledge about OTA's to well, some knowledge? Two of his books are both recommended if you want to learn how older OTA synth designs work: "Making music with the 3080" and "An Analog Synthesizer for the 21st century".

Each book features schematics for different VCO's.  The former, 3080 based; the latter 13700 based.

If you've studied audioDIY for synths you've probably run into these IC's before; in goes (low) voltage; out comes current, and best of all, you can control the output current in a fairly linear fashion with an independent "gain" current.  But it's not quite that easy:
The gain input lives a diode drop above V--.  So to make this go, you often have to suck current OUT of the chip which seems to me oddly counterintuitive. Hello?.....OK....If you put too much current into the gain pin (2mA I th…

Discovered by accident: Low parts count waveshaper/modulator/distortion circuits!

At the bench trying to learn more about inductors--something I've not worked with a lot with before--so bought a few Neutrik NTE1s from Amazon.

It's a 1:1 transformer (making the math easier I figure) and has decent audio specs.  And it's cheap--about $14USD each, for decent audio performance; good for experimenting.

What can we do with this little gadget?

Benchtime! my goal one day is to come up with something cool like the Moog 914 (yeh right, I have a long way to go).  breadboarding up some transfomer/cap widgets, got bored, some inductor/transformer/RC/op amp widgets, got bored again, so breadboarded some transfomer/zener widgets,  when all of a sudden I heard what sounded like a balanced modulator output coming from the my bench's audio monitor.


I looked over my work and realized (after a bit) an op amp I was using as an output buffer was oscillating (unintentionally) and I wired things backwards, confusing the breadboard inputs with its outputs!!

So instead…

Tape Deck Mult Panel--An Easy One (Two)

I guess I like the Tascam SS-R220 stereo solid state recorder....I own three of these....
What is good about these?

Good bang for the buckDecent A/D D/A without paying a fortuneDigital IO so you can use better D/A if you want (I use a UA 2192 and one of these for mastering--always liked the way the 2192 AD-DA sounded).The SS-R200 RCA inputs accepts synth 5V P/P signals without a lot of fussGood, easy to use front panel UIGood manualWorks on SD cards, which are cheaper (and taste better) than a Big MacRemote control with a long cord (hey!)

In other words, someone at Tascam did good work on this one.

So what does this have to do with DIY?  I want to do sound on sound, 2 of these in one rack, so I figure I'd build a couple of quick mult-panels to accommodate, with some normals etc.
After sleeping on it, bingo, I know how I want to do this.
Hand drawn wiring setup (rear view) looks like this:

I use 3.5mm "normalled" TS jacks for my DIY work--I had to choose something, and al…

Getting started with AudioDIY and the Atmel ATTINY85: What to do with these tiny things?

I can't help but be seduced by an Arduino that, from about a foot away, looks like an op amp. And costs only a bit more!!!

I'm talking about the ATTINY, which in its "85" form looks like this:

Can we really pack an Arduino punch into an 8 PIN chip?

Time to find out!

I bought a few of the ATTINY85's ($2-3 for DIP, good for prototyping; under a dollar US for surface mount) and a Sparkfun programmer for about $15 from Amazon:
From my reading, programming ATTINY using the Sparkfun is pretty straightforward--I figured I'd have the LED blink app up and running in 10 minutes?

But it didn't work!  10 minutes became a couple of hours....


I have 2 computers I use for Arduino programming on my bench and the Sparkfun programmer didn't work on either: an older MacBookPro running OS-X Mountain Lion and a Lenovo T430 running CentOS 7.  I have used both many times for programming Nanos such as the one used for the SynthDMV.

After following the Sparkfun instruc…

Mad Bees! Avalanche Ramp Oscillator--Smells like Insect Spirit

Greets again fellow synth nerds:

I broke my own rule of DIY and perfboarded a new design. The rule: I figure it's quicker these days for me to use Eagle to craft a PCB I want to mess with, kludge in any parts, and see if I can get it to work. If I can great, if not, toss it and start over....but not this time....

The back story?

I was up late watching my usual youtube electronics vids to help me fall asleep (Carlson's lab is a favorite for that! 2+ hours of a Canadian tech saying "abooot" while restoring a tube amp? This guy is awesome!) and came across this Colin Furze clone DIY audio dude. At least he's a synth player, he doesn't ride around on jet powered bicycles and you gotta love that earring!

Close enough!

OK Sir Thomas Dolby-Colin Furze's kid brother has a super fun series of vids about using a NPN as an "avalanche oscillator".  (BTW I really like his videos! All kinds of great stuff! Mr. Carlson's energy and then some! be y…

Arduino based SYNTHDVM--Up and Running.

Hello again, yes it all works.

The SynthDVM is as far along as I think i will take it.

For anyone who wants to catch up:

Part 1  is here--as I try to master the art of undocumented Arduino clones and parts

Part 2 is here. Design goals for the project.

Part 3 is here. Let's get the OLED meter to look "analog"

Part 4 is here.  clobber that op amp!

About the DVM, It reads DC from about -10.5 to +10.5V with an accuracy of better than 1% throughout its entire sweep--very close to .5% for say 5V and pretty much dead on between +/- 3V.  As they say (I say)  in audio DIYland "good enough".

If I designed a custom PCB for this, which I see little point in doing, with a good layout and large ground plane, it'd probably perform better but it's not bad for a sandbox PCB, a nano, and a handful of opamps.

There were some evenings of cursing over this one, I had some ripple on the Opamp + and - rails I couldn't get rid of, but I finally re soldered a few traces here an…