Sunday, December 23, 2012

International Karate (C64 music remake)

A Commodore 64 game music remake

I decided to do a quick remake of a C64 game song, just for fun.
Though I own plenty of VST synthesizers, the goal was to only use analog synthesizers and no overdub, i.e. only one instrument per sound. So you only hear the Juno-60 playing a single sound for instance.
I didn't know which song to pick, but after a short while chose the main song for the game International Karate, composed by Rob Hubbard.

Actually, I'm not too pleased with the result.
Some sounds (like the first one, heh) have an annoying ringing that I didn't bother removing. I guess I'm using too much resonance...
This was just a quick experiment so I don't care if it doesn't sound all that good.

Anyway, I thought I'd share it, so here it is:
(Update: I replaced that first sound with something better, so it's not piercing your eardrums any longer :) )

Saturday, December 22, 2012

Repairing an EHX Super Space Drum

Electro Harmonix SSD repair

Somebody had noticed I had done some repairs on my own gear and asked me if I could take a look at an EHX Super Space Drum that wasn't working.
Symptoms were that it started to not trigger well until it finally gave up and refused to trigger at all. I had absolutely no idea what could have caused it and my initial thought was some sort of bad connection or other mechanical problem.
I had never repaired anything for someone else and I didn't have any pressure on me really. It was more of a "just see if you can do something about it" request, so I thought it'd be fun to give it a shot!

Unfortunately I forgot to take a picture of it so I'm using a frame of a video clip I made with it :)
The picture is from AFTER I had serviced it. Read on if you're curious about the alligator clips to the left.

Saturday, December 8, 2012

Lab power supply blew up


So, I was sitting trying to figure out why an EHX Super Space Drum (which I was repairing for someone else) wasn't working.
All of a sudden, I heard a loud pop, like somebody claps their hands once, right next to your ear.
It was really loud and felt like it almost started ringing in my ear.
Of course I had no idea what it was and got really scared I had blown something up in the EHX thing I was repairing, because it wasn't mine...
Though, I suspected it was the power supply, because .. what else could it be? It sounded like a capacitor blowing up. So, I switched it off and continued my repair using my other power supply...

When the EHX thing was done I opened the suspected power supply and looked inside.
This is what I found just laying on the bottom...
Yes, it's empty.

Monday, November 5, 2012

Sampler maintenance and upgrade

A proper Prophet 2002 repair and upgrade

I actually found a guy selling a 2nd hand R-235 potentiometer as well as the knob that goes on it. I got it in my mail about a week ago and tonight I decided to remove my ugly replacement and put the right part in.
While I had it open on my workbench I also decided it's a good opportunity to install the Lotharek SDHxC SD card floppy emulator.

Tuesday, October 23, 2012

Got a Roland SH-7 :)

A big old Roland from the 70s!

I bought myself a present, since my birthday is coming up... (or at least that's my excuse)

It's the Roland SH-7 !

Some modular changes

Need more VCOs!

Someone was selling eight(!) A-111-1 VCOs. After he'd sold five of them I grabbed two :)
The problem is that I've run out of space in my cabinet.
I decided that the A-145 LFO was kind of redundant, as I have 5 other LFOs in the system, hehe...
So, out with that, rearranged stuff a bit and in with the two A-111-1 CEM3340 VCOs!
Here's an updated view of the cabinet, with (almost) no patch cables :)

Well, that was all. Nothing more to say about it really...

Tuesday, September 18, 2012

Populated Eurorack Modular

I guess I should take a photo of it with all the modules in place.
An empty case doesn't look that exciting. It looks far better now :)
Truth be told, I haven't really been using it a lot (or any other of my gear for that matter) for a while now.
I'm lazy... Uninspired... Plus, my interest in these things comes and goes.
Enough talk. Here's the photo :)

Looks a bit messy with the wires, but that's what it's like to use it!

Saturday, June 30, 2012

Polysix finally gets MIDIfied

After a long wait, the Polysix has gotten the CHD Elektroservice MIDI retrofit kit installed! :)

Actually, I installed it a couple of days after installing the Poly-61 kit.

However, I couldn't get this Polysix kit to work straight away!
Knowing that my Polysix has had some problems in the past, I wasn't sure what caused it.

Depeche Mode - Tora! Tora! Tora! (Cover by me)

I just thought I'd make a link to a youtube upload I made a couple of weeks ago.
It's a cover of the Depeche Mode song "Tora! Tora! Tora!" which I recorded about a year ago.

I'm not too happy with the kick (sounds weak) and the spooky theremin-like sound in the chorus could've been a bit louder.
Other than that I guess it's alright :)

Here it is:

Again there is a soundcloud alternative if you prefer:

Saturday, June 2, 2012

TC5514APL-3 SRAM tester

Ok, this may seem a bit silly...
I recently purchased a tube with 20 pieces of TC5514APL-3 1024x4bit SRAM.
That's 4kbit, or 512 bytes if you will... Access time 300ns.
It's an 18-pin DIP chip.
Why would anybody want an old crappy memory like that?
Well because it's used in some old synthesizers of course!

As far as I know, it's used in the Korg Polysix (that I own) and the Korg MonoPoly.
Probably more machines than that. Or at least it might be possible to use it as replacement for other similar memory chips in other synthesizers.

Aaanyway... How do I make sure they work?
I don't want to open my Polysix, remove my chip, put a socket in its place and use the Polysix as a testbed for them. Also, that's not a fun way to test them.
Now I have an excuse to start yet another project: The TC5514APL-3 tester! :)

Replaced Prophet 2002 data potentiometer.

This is so stupid...
Whyyyyy!? Sequential Circuits Inc...
They like pissing people off by using potentiometers that are ever so slightly smaller than your standard off-the-shelf potentiometers.
They're called R-235 and seem to be linear 10k potentiometers.
Here are the measurements I got (using a caliper) from the one I removed.

Matrix-6 volume board (incl slider) replaced.

After giving up trying to find a replacement slide potentiometer that fits the Matrix-6, in combination with the awful condition of the small board the slider is mounted on, I found an old board for sale at .

They know how to charge for their parts but I figured it has been long enough without any other solution.
So, I ordered the volume board, took the old one out, installed the new one...

Tuesday, May 1, 2012

Juno-60 service

Still acting weird? Ground problems!

Just when I thought I had fixed all the problems with the Juno-60, I noticed it started jumping into manual mode and acting weird again when I was mocing the sliders.
Now what?!

Becoming a Eurocrack addict

Doepfer LC9 Modular synthesizer case

OK. I caved in.
I have the money.
I have the desire.
I have the space (actually I'm not sure I do, but I'll make some, heh).
It's time to go modular!

So I just bought the case for my first modular synthesizer!
Look at it! See how empty it is...

Saturday, April 14, 2012

Simple CV/Trigger switch box

I like my Yamaha CS-30.
I like my Kenton Pro Solo Mk II.
I DON'T like that I have to plug the CV/Trigger cables in and out every time I want to switch between letting the Pro Solo control the CS-30 and playing the CS-30 keyboard myself.

Solution: Make a simple box that lets me choose which "mode" I want to use the CS-30 in.

Friday, April 6, 2012

Poly-61 MIDIfied!

Finally, after two years, I installed the CHD Elektroservis Poly-61 MIDI retrofit kit!
So why did it take so long? First and foremost, I'm lazy, OK? Takes me forever to get my thumbs out and actually do something that I really want to do.
Second, and this is a practical reason, I didn't have any good way of making a 16mm diameter hole for the MIDI connector, and I sure wasn't going to have a dangling MIDI-connector next to the synth.
Most people don't have drilling machines that can handle drills with 16mm diameter.

One way could be using a conical drill, preferably stepped. That seemed like a good way to screw everything up since I don't have anything to keep everything in place with. No vise, no pillar drill...
So, after winning a 5/8 inch (15.875mm) hole punch on an online auction, I got to work the same day it arrived in my mailbox. If you don't know what a hole punch is or how it works, look it up.
It's really great!

Thursday, April 5, 2012

Sequential Circuits Prophet 2002 plus

Sequential Circuits Prophet 2002 plus

This didn't cost me much (around 115 Euro) and I was curious to see how I'd feel about owning a hardware sampler again.
It's the Sequential Circuits Inc (or SCI for short) Prophet 2002 plus!

Yeah, a broken knob :(

Sunday, January 22, 2012

Roland JX-8P finally working

JX-8P is working!(for real)

In my previous post I wrote about replacing the rectifiers.
So, I removed the two. One is for the +/- 15V, one is for the +5V.
I'm no expert, but I'd say one of these is in less than perfect condition...

That right one... Hmm.....