The Coin Battery Situation on the Siel DK80 Is A Bit Unusual

In my previous video you saw me tear down a Siel DK80. Today I am going to replace the lithium coin battery. Be sure to backup your patches to the cartridge before proceeding.

I make Eurorack modules with Mojo, Shop NOW on Reverb :D

Roland Juno-106 Synthesizer Troubleshooting/Repair Quiet Voice

Today I'm investigating an issue with a Roland Juno-106. Voice #4 is a lot quieter than the others. And it's not a calibration issue. 99% certain it is NOT the brand new voice chips I put in as seen in a previous video. Troubleshooting will confirm that statement. So what else could it be? Maybe something EVERY 106 owner will want to be pro-active about mitigating?

This video is posted for general information about my experiences. Always observe safety working on electronics, and never tinker around inside power supplies without first unplugging the power cord. De-soldering components on the Juno-106 must be done VERY CAUTIOUSLY to avoid lifting very tiny delicate traces. If you're not sure about anything, there's no shame in taking your instrument to a qualified service technician.

Timestamps
0:00 Intro + Symptoms
0:35 Voice Chip Swap Test
1:06 Looking at the Wave Chip output
1:56 Waveform Chip replacement
2:23 Testing
2:51 Voice Board inspection and Remedy
3:19 Re-testing, did it work?

Be sure to check out my cool eurorack modules in my Reverb Store :D

Sequential Drumtraks Drum Machine Repair

Today I'm investigating issues with a Sequential Drumtraks. While it is making sounds, the display is glitching out and the control functions are not working. In the end it was only incidental I was able to get it working again, for reasons I don't fully understand. The same phenomenon happens with my Drumulator, that's how I knew what to check for. It's my hope posting this video, that someone more knowledgable will be able to comment about this phenomenon.

This video is posted for general information about my experiences. Always observe safety working on electronics, and never tinker around inside power supplies without first unplugging the power cord. If you're not sure about anything, there's no shame in taking your instrument to a qualified service technician.

Since filming the video, I've discovered the batteries are still made in Japan. Also, the numbers on the battery may or may not necessarily be a date code. My new battery says 2132, so maybe it was made in 2021? Since the manufacture date and date installed may differ by a couple of years, I now write a date on the battery with a sharpie when I install it.

Timestamps
0:00 Intro + Symptoms
0:28 Power Supply investigation
2:10 Battery
2:28 Data Bus Check
4:08 About Cleaning IC pins
4:28 Last ditch effort and suddenly it's working???
5:38 Short demo

I design analog Eurorack modules, check my Reverb store for availability.

104HP Eurorack Case Build From Cigar Boxes Timelapse

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Today a timelapse build: a 104HP Eurorack case from cigar boxes. These are nice Spanish cedar cabinets, not cardboard. First I build a suitable box, install rack rails. Then solder together a bus board and install power supply. Last, putting all the modules inside.

Power Supply | Tiptop uZeus
Bus Board | Synthrotek Noise Filtering Distro
Rails + Nut Strip | Synthrotek 3mm
Screws | After Later 3mm

This video was made for general entertainment purposes only. Activities in this video are not recommended without proper training and safety. If you are using woodworking power tools: always observe safety precautions, wear protective eyewear, and read user manuals to prevent accidental bodily injury.

The audio in this video used these modules:
G-Storm Electro: 101-VCO, 101-VCF, 4027 VCO, T2K-VCF, diy buffered multiple, 2xADSR, 2xVCA, Polychrome Phaser
4ms Rotating Clock Divider
Synthrotek DLY
Qu-Bit Data Bender
Feedback Modules CP3- Mixer
Pittsburgh Modular Outs
along w/ Behringer RD-8, snare has Empress Reverb
Recorded direct, no other mastering or effects.

Converting a Boss PH-2 Phaser Pedal to Eurorack + Audio Demo

Today, the title says it all what I am doing.
Link to Hexinverter step flashing video https://youtu.be/n-ugh8sbHw4

0:00 Introduction
0:50 Teardown
1:42 Planning
3:56 Notes on Assembly
4:24 Audio Demo

Announcing 2xADSR r1-2 Dual Eurorack Envelope Demo

Today a quick un-edited video announcing the 2xADSR version 1-2 dual envelope. Available as a DIY project or assembled version. Check my Reverb Store for availability. More specs and details at ModularGrid. DIY build info at Muffwiggler.

CP3- Audio Mixer [USER REVIEW + Demo] by Feedback DIY SMD Eurorack

This is the second video in a series of user reviews.
I am focusing on DIY eurorack modules by the maker Feedback.
In other videos I have covered their Static and Squeeze modules.
Today I am looking at the DIY CP3- Mixer derived from the Moog modular.
I will be giving some quick thoughts about the build.
But focus more on demo-ing some sounds.
The CP3-type mixer uses all discrete components, there are no IC chips inside!
At the end I give some concluding remarks.
But don't take my word for it.
In this video I will run all sorts of sounds through the CP3- so you can judge for yourself.

Timestamps
0:00 Introduction
0:52 Quick Notes About Assembly
1:12 The Format of the Audio Demos
1:47 Audio: 101-VCO Raw Oscillators
3:38 Audio: 4027 VCO Raw Oscillators
3:38 Audio: DNA Symbiotic Waves
5:50 Audio: 101-VCO Bassline, Arpeggio
6:10 Concluding Remarks

Recorded direct to Tascam DR-05.
No additional mastering or processing.
Find more info about CP3- Mixer at Modular Grid

Squeeze Audio Compressor by Feedback [USER REVIEW + Demo] DIY SMD Eurorack

User review of the DIY Squeeze Audio Compressor by Feedback electronics.
I'll demo some sounds, give some audio compression tips,
and make a Future Sound of London Big Breakbeat patch.
You don't want to miss that one!
Give some thoughts about building the DIY version.
And conclude with some brief remarks.
I am not affiliated w/ Feedback Modules.

Timestamps
0:00 Cold Open Sounds
0:34 Introduction
2:09 Assembly Notes
4:33 Audio: Drumbrute Impact + Reverb
5:28 Audio: Parallel Compression Trick
6:41 Audio: Arpeggio + Reverb
8:10 Audio: Gluing A Mix Together with Compression
9:48 Patch: Future Sound of London Big Breakbeat
11:43 Concluding Remarks

Recorded direct to Tascam DR-05.
No additional mastering or processing.

Makeshift VHS Tape Ribbon Controller In 3-Minutes

Haven't had any synth repairs or DIY hacks in a while.
A buddy sent a FB video link and asked what's up with this.
Somebody was using a videotape as a makeshift ribbon controller.
Using the tape to send a control voltage to their modular gear.
You may have seen something like this, but wondered about the details required.

Does it actually work?
If so what are the necessary steps?
Let's find out.

Happy Holidays

Wanted to wish everyone happy holidays. And to thank you for your continued support. 2018 has been a great year, and kept me very busy. In fact, I've been hard at work through the holidays to bring you the best eurorack modules and more. Be sure to check them out in my Reverb Store. Fantastic new modules and content are planned for 2019, so be sure to check back often. Happy New Year!

Akai S900 Sampler Floppy Disk Drive Cleaning [No Soldering]

Floppy Drive on your S900 not working?
Does it take a while to warm up before the floppy starts working right?

You may be able to bring your disk drive back to life and/or improve its performance with a little cleaning and maintenance. In this video I show how the S900 floppy drive can be removed and cleaned with some simple tips.

Why would anyone want to mess w/ archaic floppy disk drives? While USB drive emulators are available which greatly increase the convenience and storage capacity of sample banks...
For me it's nostalgia. I just like floppies, you can still find boxes of blank floppies at thrift stores and garage sales. I also still use cassette tapes, some vinyl, and still buy CDs as well.

These tips may not guarantee results in every situation. The S950 and other samplers may differ in design/construction. However, these tips may possibly help you with other devices like E-mu, Ensoniq, Kawai, etc.

Beware! If you're not confident or experienced in electronic disassembly or repair, there's no shame in taking your sampler to a qualified technician. Floppy drives are delicate and have easily broken parts and bezels. You MUST unplug your sampler before attempting any service inside. Take all necessary precautions regarding static electricity discharge so as to not damage any sensitive electronics inside.

2xADSR Dual Envelope DIY Project

And here it is...a dual 4-Stage envelope generator 8HP Eurorack. 2xADSR is a dual envelope module in 8HP Eurorack format based on the Arturia Minibrute. The schematics are openly published on the internet, so it would seem reasonable to have adapted a fun DIY panel/pcb project for educational purposes under fair use. Each envelope is an independent Attack-Decay-Sustain-Release linear contour. Each envelope takes a gate input, puts out a positive-voltage contour and a buffered negative-voltage (DC inverted) contour.

This is a DIY project, just a pcb/panel only, with surface-mount soldering required. You supply the parts components (not included), but it uses all very affordable and easy-to-find parts. I would not recommend this as your very first SMT build, maybe your 2nd or 3rd SMT build though. The BOM and Schematics for this project can be found on muffwiggler
PCB/panel are available in my Reverb Store

Spring Tank Reverb Breadboard Eurorack Demo

Try not to let your heads explode when this sickness fondles your eardrums. Got my hands on an O.C. Electronics Spring Tank Reverb. On the breadboard I've built a driver circuit with voltage control of the wet/dry crossfader. Who does that???!!....

I do that. And today's demo shows you why. The Future Retro Transient+ is going through the spring tank. The mix is set mostly dry, but I'm using a short envelope to send a burst of reverb wet mix when the snare hits. Using the Beatstep Pro for that. That's what I'm talking about. That. Is what it's all about.

How did I do this? I've frankenstein'd a couple of circuits/ideas together to make this happen. At its core is a Tombolas DIY Spring Reverb Circuit w/ EQ and Drive Control to accommodate a wide variety of tanks. It worked very well, but I was not yet satisfied. For the Voltage Control, I've slapped away the final amp mix stage and replaced it w/ the VC Crossfader circuit by Thomas Henry. I dumped his VCA control, that's another project for another day, and to made some minor changes so it would play nice w/ the Tombolas circuit.

Testing A Ring Mod + Sub-Oscillator Circuit

In these quick videos I am testing a DIY Ring Mod + Sub Oscillator circuit through my Tonus VCF (ARP 2600 clone of the 4012 filter). The first video is through a Timefactor Delay. The second video I am punching into freeze mode on the Strymon Big Sky for a colossal wall of sound! The Ring Mod + Sub will become a eurorack module, I will give more info on that soon. Sequenced on Arturia Beatstep Pro. Thanks for watching!

Building A Eurorack Module By Hand

In this video I show my process for building a Eurorack module by hand

Korg MS-20 Teardown: Pulse Width Modulation Install

The vintage Korg MS-20 monophonic synthesizer comes with a pulse width knob, but no way to patch a modulation to it. In this video I teardown the MS-20, and install a Pulse Width Modulation routing.

My PWM will come from the MG/T.Ext circuit that is already present on the synth. 90% of the time I want to use the MG, AKA the LFO, to modulate the Pulse Width. So all I will do is add a small pot and current limiting resistor for routing the MG/Total circuit to the Pulse Width.

What about the other 10% of the time I don't want MG going to PWM? Well the MG is only normalled to the Total/External jack. If something is patched into the Total jack, it will override the MG and be routed to the new PWM pot. It behaves exactly the same way as the MG/Total pots for Pitch/HPF/LPF. Pretty sweet.

At the end of the video I patch various things to modulate the Pulse Width. Stay safe, don't electrocute yourself, and be sure to unplug the synth at all times while doing work inside the unit.

Oberheim Matrix-12 Synthesizer Power Supply Issues RESOLVED

In this video I show what I did to resolve my power supply issues on the Oberheim Matrix-12 analog synthesizer. Symptoms were intermittent non-boot, locking up, and the dreaded Voice 1 Processor Malfunction message. Along the way I'll talk about how the power supply works and how it is different than many synths from the era prior to this. Even though the Oberheim Xpander is a little different than the Matrix-12, its power supply works exactly the same. This may not enable you to fix your Matrix-12/Xpander completely, nor answer ALL questions you may have...but hopefully it will be helpful information.

YOU ASSUME ALL RISK WHEN REPAIRING YOUR OWN ELECTRONIC INSTRUMENTS! There's no shame in asking a friend for help or taking it to a reputable synthesizer technician. BE SURE TO UNPLUG THE SYNTH PRIOR TO DOING THIS KIND OF WORK.

0:00 Introduction
1:10 Getting Started
1:54 Dealing with an SMPS
3:16 Why did Oberheim use an SMPS?
3:40 Why I'm NOT going to troubleshoot this power supply
4:38 Power Supply Restoration and Results


Here are the Mouser parts numbers:
Power Entry Module - 871-B84771A0001A000
2W Shunt Resistors 0.1ohm - 667-ERX-2SZGR10V
sorry I don't have capacitor numbers, I did that work 2 years ago

Arturia Beatstep Pro Sequencer Repair Project

Did you know I have interesting things listed on Reverb? Check it out now. In this video I attempt to repair my Arturia Beatstep Pro sequencer controller. It is having intermittent power problems, I want to replace the USB port w/ a different kind. My warranty ran out in September, so no wukkas. This is only my second project doing SMT (Surface Mount Technology) type work, and I find myself needing to revise my plans. Next time I will buy some solder paste and do it right, lesson learned. At the end of the video I test my work by doing a little Acid House w/ a Korg MS-20 synthesizer and a Roland TR-8 drum machine. If you like synth and electronic guts click the LIKE button.

You may have read my post on my previous repair. I'm not sure if it didn't hold, or there was a problem w/ the USB jack/cable. Whatever the case, it was only a temporary fix.

Arturia Beatstep Pro Sequencer USB Port Jack Easy DIY Repair

Any system is only as strong as its weakest link.

Enter the Arturia Beatstep Pro Sequencer, tons of user reviews boast solid construction seemingly built like a tank. On the first few uses I would be inclined to agree. However after about a dozen uses the USB port jack on mine has become intermittent. Symptoms include sudden power blackouts and reboots, even when not touching the USB cord. You don't have to play out live to a crowd to know, this is no bueno. I am careful and take care of my gear. I am especially careful with the USB port and its cord, however I run a bunch of other connections back there and the wires usually hang up with the USB cord. Why is this happening?

One condition could be contact fatigue. If you plug/remove the USB cord a lot, the little contacts could become worn away. You will frequently see this in older cell phones. But more likely as in my scenario, the lead-free solder on the USB ground pins disintegrated resulting in a faulty solder joint at the circuit board. It would be too easy to blame the RoHS standard for requiring lead-free solder, which is structurally deficient for such a use. But if I worked in a factory around solder all day long, lead-free is the way to be. What can be done about it?

If the item is still under warranty you could send it to the company and they can fix or repair the item. There may be a repair charge if the company deems the issue to be caused by negligence. And who's to say? Even if there is no charge, you could get your sequencer back and have the same thing happen again. I'm only mentioning all of this because if you choose to repair the USB port yourself, it WILL void your warranty. Also, if you're not careful and touch something electronically sensitive, you may accidentally damage something else. I'm not liable for anything you do, so be careful not to shock yourself. If you're not confident in doing these things, there's no shame in getting an electronics friend or service tech to help. You have been warned. Now let's fix this thing already.

1. Flip the sequencer over and remove all the black screws. Remove the metal back plate. This will expose the circuit board. Remove all the little screws holding the circuit board in place.

2. In this orientation, pull the circuit board away from you to dislodge the minijacks from the case. Then lift the edge closest to you up and away. If this isn't happening, check you have removed ALL the little screws, it may be easy to miss 1 or 2.

3. Flip the circuit board over and note the location of the USB jack near the power switch.

4. Using regular rosin core solder (I use 60/40 from Radio Shack), make new solder joints on the two GROUND pin locations at the locations shown by red arrows. Make sure the pins get soldered nicely to the circuit board contact pins here. I needed a magnifier to see the work area.

5. Put the circuit board back in and secure it to the case with the screws. This is the time to plug in and test it, making sure you DO NOT touch any of the electronic components inside while you do so. At this point you will be able to wiggle the USB cord lightly and make sure it does not blink the power. If so, you'll need to do it over. Or there may be something else going on. Hopefully this has been helpful, this is what I did to restore mine to working order. If everything is good, you can go ahead and put everything back together.