Friday, January 11, 2013

Akai S3000 MIDI + SCSI Retrofit

I really like my Akai S3000. It is an oldschool beast of a sampler, and if you know your way around the menu structure, you're able to get complex sounds in very little time.
However, there were a few things that annoyed me a bit. 
Here is what I did:

First of all, I really wanted a second MIDI input. Constantly replugging Midi cables (while crawling in the narrow space behind the rack) is not my idea of fun. I made an addon card based on the Midi Merger (sorry, no direct link possible). It does exactly what the name suggests: it merges two MIDI inputs to a single output. Now I route that output to the MIDI IN of the Akai with a short cable - voila! - two MIDI inputs. (Yes, I know in the first picture the two optocouplers are not yet in their sockets...) Now I can connect my hardware sequencer and my MIDI interface at the same time, and I can use them separately or in combination.

The other major thing was the floppy drive. Juggling all those 1.44MB disks is sooo 90ies, and when I came across an old SCSI Harddisk (Quantum ProDrive with whopping 120MB - that is megabytes) I put it in the sampler. This gave me a bit of an headache, as there is NO documentation for the S3000 on the net whatsoever (only for the S3000XL, which is a different animal). I won't go into detail about the hellish nightmares here, but let me say this: why on earth did Akai decide to use standard SCSI cables, but then they build a sampler that requires them to be plugged in backwards??? We'll never know.) Anyway, after waaaay to much time experimenting and reading obscure forum posts from like 1997 or so, I got it to work by filing off the notch on the cable that (kinda rightfully) forces you to plug it in only one way.

I could have been happy, but there is always a ...but

When you turn on the sampler, it will boot its OS from a ROM, then it will look for an updated OS on the disk, and then boot into that. Only, the old and slow HDD never was ready spinning up at that point, which always gave me a "disk not ready" error. I always had to load the updated OS manually. How annoying.

I added a small 555-based "delayed power on" circuit to the addon card. This handy dandy thing closes a relay after 3 seconds. This relay actually switches the +5V power line going to the mainboard.
When you power on the Akai now the following is happening: power is applied to the harddisk, which starts spinning. 3 seconds pass, the relay (the small orange box on the back of the circuit board) closes with a CLICK. Only now the mainboard is powered on, thus the sampler starts to boot. Because the HDD now has had some extra time to get ready, the S3000 can happily read the OS from the disk and boot into that. READY.
I am also thinking of making the frontpanel detachable like on the S6000, but that is for another day.

Tuesday, January 8, 2013

Böhm Soundlab Multi Module

This one is a bit embarrassing... A friend of mine is a proud owner of a Böhm Soundlab Modular Synthesizer. About 300 or so were ever made, and at least half of them were destroyed when the warehouse of the german Böhm company burned down. Needless to say, this thing is quite rare, and modules are hard to come by.
Now, the synth comes in this somewhat flimsy hardshell suitcase, and this particular specimen had some unused space that begged to be filled in a meaningful way.
My friend asked me if I could help, and I said "Yes!" - I offered to make a module with an 8-step sequencer, a state variable VCF (LM137000 anyone?), a double CV Inverter and a double "gender bender" (to convert between banana jack and 6,3mm mono plugs); thus making the most out of the available space.
My friend said "GREAT!" and we agreed on a timeframe of about 3 months or so. You might get an idea where this is going... I started with the module and got it finished to about 85% within the first 2 months... then I moved... and did not have time to work on it....then I moved again... putting it away safely... then I thought about continuing my work (but found good excuses not to)... and finally, TWO-AND-A-FUCKING-HALF-YEARS-LATER, I finished the module (took another whopping 4 hours. I could have done it waaaaaaay earlier....). 
I had some trouble with the sequencer, it is based on the popular "Baby 10" design, and unfortunately that means the gate signals of consecutive steps are joined. Of course, we can not have that. I made it so that rather than gate signals, triggers are spat out, which in return can drive the envelope generators of the synth. It works amazingly well, and I am glad I got this one off my back. It gnawed at my conscience far too long.. but fortunately my friend is very forgiving and never really doubted me (he said so, it must be true!)
And yes, that is a 9mm shell next to the Resonance knob: I put a hole in the panel where I should not have, with a 9mm diameter. The shell just happened to lie around in the streets of Neukölln, Berlin, and it fitted perfectly. So there!

606 rescued

A friend of a friend had me repair his 606. The Bassdrum was not working, and someone added some nonfunctional modifications, which were executed rather crudely. I mean, if you are about to drill holes in an enclosure, at least make sure they line up properly! All in all, the machine was in a really bad shape. It could not even be programmed properly, because most of the switches were bouncing or not reacting at all.
After getting the Bassdrum working, I took out the existing mods and added some of my own: in the top left is BD pitch, top right are snare pitch, snare snappy and snare decay. Because of the aforementioned misaligned holes I put a piece of black plastic under the knobs as sort of a cover up. 
To round it all off I installed a Technology Transplant replacement switchboard and replacement volume pots. Beware! The Technology Transplant kit is not exactly living up to its expectations: the switches on it are definitely NOT new, as they had solder residue all over them, and on two of them even one of the four legs were broken off! Also they, too, were badly aligned, which means that when I put the switchcaps on them and assembled the 606, lots of the keys got stuck in the enclosure because there was not enough tolerance. I had to resolder at least half of the switches.
Anyhow, the 606 is working beautifully now, the owner is happy, so am I. Bumblebee.