Sunday, August 17, 2014

Yamaha TX81Z FM Synth Sounds Demo 2

The patches can be downloaded on my download page

Continuing sonic explorations of TWO TX81Z FM Synthesizer Tone Generators this time. Each unit chained for even/odd notes: one panned slightly left and the other to the right. Sounds are outrageous in the dry state but can be made completely preposterous with the Big Sky reverb.

Here's a rundown of the sounds:
0:09 Cymbiosis - Synth pad with cymbal harmonics.
0:38 Ritual - dark tribal bass. Add huge reverb to this one.
0:53 Darknights - Smooth filtered sawtooth with swell.
1:16 Heavyw8 - Super fat bass. Start your own earthquake.
1:33 Wowabass - It literally says wow.
1:44 Drum kit bass drum, snare, tabla, hats
2:34 Sawtopia - Smooth sawtooth pad w/ organ swell.
3:10 Saw Bass - Bread and butter bass.
3:19 Fortress - Super dark cello w/ vibrato.
3:51 Transistor - Hot pad inspired by the Novachord, transistor hum
4:20 Sync Bass - The way FM can bass
4:31 SmakMyBass - Prodigy Fat of the Land Bass on steroids.

Wednesday, August 13, 2014

Exploring The SH-101 Plug-Out Roland Aira System-1

The focus of this demo is the SH-101 plug-out: down-n-dirty short basses, basic arpeggios, and sequences from Arturia Beatstep. I don't have an original SH-101 so I can't comment on how similar it may be. I stayed away from tone/crusher and kept the delay/reverb to a minimum just so you could hear the SH-101 sound engine in all its monophonic glory. Some backing rhythms provided by SCI Drumtraks and Roland MC-303.

Sunday, July 13, 2014

8 Minutes with an Akai AX-80

There are quite a few good demos of the AX-80 out there already. I wanted to program a few basic sounds and some unique aspects of the AX-80. Some parts I use the Beatstep sequencer, chord memory, and the Big Sky reverb.

Saturday, July 12, 2014

5 Minutes with a System-1

Quick demo of some sounds made on the Roland Aira System-1 Synthesizer.

Saturday, June 14, 2014


5 minutes of your time listening to the Korg Poly-61 6-voice hybrid analog/digital synthesizer. Paid $50 for this hot mess because it was absolutely BRICKED. As you hear some functions working again but it is still fussy as you see at the end of the clip. Sequential Drumtraks and Strymon Big Sky also featured.

Friday, June 6, 2014

Korg Poly-61 Key Contact Repair

Key contacts are the source of much headache on the Poly-61.  Much has been blogged and posted by others about dis-assembly of the keybed, membranes, and maintaining clean key contacts.  However in the case of THIS machine no amount of cleaning could bring back key functionality.  I believe this is due to the membranes simply wearing out and the gold contacts losing much of their conductance.  Replacement membranes are very expensive, and I wanted to explore cost-effective methods to milk the last bit-of-life from this keybed.

This repair involves re-coating the membrane contacts with a conductive pen, adding plastic shims to the keys, and replacing broken key bushings that have allowed the keys to sway too much side-to-side.  The biggest disadvantage to this repair is a small number of keys are STILL un-responsive.  Furthermore, re-coating the contacts in this manner will produce an effect known as bouncing.  Bouncing is when a key is pressed it may send two, or several, note-on signals in rapid fire succession.  This is because the contact, on its way to being fully depressed, will bounce several times on-and-off before settling.  To me I can live with this more than have a dead keybed that does nothing.  Anyway...on with the repair process.
Using a CircuitWriter pen from radioshack I coated the membrane contacts twice, with 4 hours between coats. I allowed the contacts to cure overnight. 
Using the pen takes finesse. Shake vigorously for at least 2 minutes after the little ball becomes free. Practice on something else first. Press until flow starts for two seconds, then swirl in circular motion to cover surface of contact.  Here's what the covered contacts now look like. Next to add plastic to the bottom of the keys. After experimentation, I found a 1mm thick plastic was required, cut to 8mm x 10mm rectangles. I searched far and wide, and found an Artists Loft brand graph ruler from Michael's was perfect material. Tricky to cut with an exacto knife, but can be scored and bent to finish the cuts. This photo shows the rectangle in place on one of the keys. To tape it in place I used good old fashioned duct tape, the perfect redneck engineering solution. Replace and test the key. Another piece of tape was sometimes necessary. I found three layers of tape to cause errant self-triggering of the key. Next I replaced some damaged key bushings. First, you guessed it, I used duct tape to build up a base layer on the bushing prong. In this photo you also see a bare prong, a good bushing, and another damaged bushing. Then I cut a small piece of 3/16" Heat Shrink Tubing to place over the prong. This photo shows the heat shrink tubing in place. I found the tubing fit snugly without any heat being necessary. It's not a perfect replacement for an actual bushing, but it greatly improved the keys swaying side-to-side. And that's it.

Thursday, May 1, 2014

16-Step MIDI Filter Sequencer

The designs for the Step Control Sequencer are at

Following two months developing code and playing with breadboards I present this quick demo of the recently completed DIY digital 16-step control sequencer. This sequencer was designed for controlling filter steps on an MS-20 mini. The sequencer puts out variable step control voltages up to +5 volts and synchronizes to midi start/stop/clock messages. To achieve control over 16-steps with only 8 pots, I employed a toggle switch that can program steps 1-8 or steps 9-16 without reading changes until the pot positions are changed. All the control processing happens on the Arduino Mega. I have prototyped two circuit boards for this project. The first is a midi shield. The midi shield features one minijack control voltage output, one midi input with an opto-isolator, and one midi thru port. The second board I made is a panel control used for the pots and LEDs. The Arturia Beatstep is the master clock and is sending midi note data to the MS-20 at the same time the step-sequencer is controlling the filter with control voltages. The Sequential Drumtraks is put in slave mode for this demo.

Friday, April 4, 2014


Here's a little thing I whipped out using a Matrix-6 and some reverb.

Friday, February 7, 2014

Cerulean (Darkening Sky Mix)

String Synthesizer Elite Demo

Been a while since I posted. Hope your year is starting off right. I've been trying to suss out some power supply issues on a Matrix-12, and working on remixes. I'll be set to post one soon. In the meantime I had a whim today of a string synthesizer extravaganza....

Presented for your viewing pleasure are three of the creamiest string synthesizer elite: Logan/Honer String Melody II, ARP/Eminent Solina SE-IV, and the VP-330 MKI. Behold these heavenly machines in a side-by-side sound comparison. With a special appearance by my hand built JH Triple Chorus ensemble module, auditioned with a dry Solina signal run through.