Circuit Bent Akai S01 Sampler

It has been a marathon week of circuit bending for me.  After knocking out the Roland DDR-30, I turned my sights to the Akai S01.  Almost 20 years old, the Akai S01 is, to put it mildly, a bit of a relic.  I originally picked mine up in the late 90’s for around $100.  Nowadays it’s…well…not that valuable.  With 15.6 seconds of sample memory, it’s power is dwarfed by any of today’s soft samplers.

The process for this bend was very similar to the DDR-30.  I identified the two chips of interest and started wiring up leads for the 1/8 inch jack patch panel.  The biggest issue was the fact that I was working with a surface mount chip vs the DIP ROMs on the DDR-30.  This made for some very tight wiring.  The first chip wasn’t too much of a problem, however the second gave me no end of trouble.  After wiring up the lower chip, I realized that I had a number of contacts touching.

Tight wiring.

As I started probing to identify the short circuits, I found that most of the pins on the second chip linked directly to the same pins on the first chip (something that should have occurred to me before).  With that knowledge, I started pulling off the wires that shared a contact with the first chip, leaving only a few unique bend points.

Completed wiring. Note there are only a few unique bend points on chip #2.

The front panel was done the same way as the previous one, although I added four multiples to help expand the patching possibilities.

Drilling the patch panel.

Wired patch panel.

Another shot of the inside before closing things up.

I’m learning that a circuit bent S01 has a ton of sound mangling possibilities, although there are a few bends that effectively kill the MIDI signal to the unit.  Also, it seems like you need to strip out the patch cables before you can reload sounds from the floppy disk.  All in all though, I’m very excited to start digging into this.  Here’s a little demo of what it can do:

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About morganhendry

I have been a musician and rocket scientist since 4th grade. I play drums/keyboards for the LA based instrumental rock band Beware of Safety (www.bewareofsafety.com), write electronic music as The Laterite Road (www.thelateriteroad.com), and just landed something on Mars (mars.jpl.nasa.gov). More info can be found at my website (www.morganhendry.com). Sign up here for updates on my many projects: http://morganhendry.fanbridge.com/
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16 Responses to Circuit Bent Akai S01 Sampler

  1. Ben says:

    Amazing, mate!! Even the samples of your loop without all the bending madness are stunning, did you make them yourself?
    I’d love to see them available in a library.

    • morganhendry says:

      Thanks dude! I’ve gotten a few comments about samples from the two circuit bent machines. Once I clear some projects from my pipeline I could probably put a few out for folks.

  2. Sebastian says:

    Thank you so much for sharing this! This week I’m going to bend one myself and used your description learning how to do the bending. However, after buying the parts in the electronics market today and talking to the shopman he rose serious doubts about whether I really should dip into the running machine and test for bending points (“Are you crazy? Never do this!”). As I never got in touch with electronics before and therefore don’t know exactly what I’m doing I guess I should leave the S01 disconnected. This leaves me with two opportunities: either bend blindly or ask someone who got things right about which points he connected exactly. Do you have the plan left that you made when identifying the short circuits and post it here / send it to me? That would be quite useful for me.
    Thanks in advance! 😉

    • amit says:

      @sebastian If youv’e never circuit bent anything before and have no knowledge of electrics you should not be messing about with mains powered gear. Find your feet bending some battery powered keyboards like a casio sk1 or something first.

    • morganhendry says:

      First off, proceed at your own risk!

      Second, definitely read this. Tons of useful information:
      http://www.circuitbenders.co.uk/tips.html

      I think in general you have to break the risks down to those of the sampler and those to you. Circuit bending is inherently unpredictable and in some cases destructive. You are doing things to circuitry that it was not designed or intended for. You cannot always predict the results, and have to walk into this knowing that you could permanently damage your sampler.

      As for yourself, there is certainly a danger to working with the voltages coming out of your wall. However, someone built your sampler and lived to tell the tale. The most important thing is to treat electricity with respect. If you have some familiarity with building or repairing electronics, you’ll understand the internal layout. Most of the circuit runs on low voltage dc, which is fed off a power block by the plug jack. You can figure out which connections are safe with a volt meter.

      Again, proceed at your own risk!

      If you look at the pictures, you’ll see the two chips that I worked on (check the chip numbers). I basically wired up most of the pins to the jacks on the patch panel. Some of the pins on the second chip map to the first, and you can check which using the continuity checker on your volt meter. This will save you a bunch of soldering. If you want a little help, I wired up every pin on the first chip, and pins 1, 13, 14, 15,17,18, 19, 20, and 21. If you search for the pin numbers, you should be able to find a spec sheet that explains how to locate each of the above pins. You can also make your life easier by using your continuity checker to track the leads from the pins on the chip to another point on the board (thereby avoiding having to solder to such tiny pins).

      I was nervous jumping into this too, but it is doable as long as you work slowly and treat the circuit with respect. I would definitely take @amit’s advice. If you have never done this before, definitely try something battery powered. You can usually find toy keyboards at radio shack that give great results and let you get your feet wet.

      Good luck!

      • Sebastian says:

        Thank’s for the reply. In the meantime a friend of mine and I bended the S01. However, for security reasons, we bended somewhat blindfolded – we soldered the cables just with the power plugged off without having checked the soldering points in advance. In total, we added nine connections which left us, for our very first bended machine, enough possibilities for exploring the possibilities. Unfortunately, one connection, if turned on, causes the machnie to crash. Nevertheless, I love playing around with it and the sounds I am able to procuce now! I think 28 combinations is fairly enough for the moment. 😉
        Thanks again!!

  3. amit says:

    Many Thanks by the way Morgan your design inspired to pick up an S01 and am in the process of doing to now. Wired up all the pins and tested and after a bit of tweaking all is good. Just wiring up the patch panel now. Couple of the pins just became too tight to work on so have left them off the patchbay. Just playing around with the internal sine wave and there are some incredible bends here. I’ve bent quite a lot of gear but have always been a bit wary of anything that has an internal transformer but your instructions were clear and I figured I could do the work with it unplugged and double check everything before powering it up. All good so far. Thanks Again.

  4. rrooyyccee says:

    Hi, nice blog post. How did you figure out which chips to start with on this unit. I’m approaching an S2000 to bend, but am not knowing which chips to start with.

  5. Neil says:

    Hi, thanks for this very inspiring article. I bought one of these new back in the day, just bought another for less than a 20th of what I paid originally!

    You very helpfully mention all the pins that you connect to but, and apologies if this is a dumb question, aren’t two of these pins connected to ground and power? I did try a quick search for the pin layout with no success. As you have all the pins connected to your patchbay I assume that no permanent damage can be caused by any of the patching permutations?

    Also, is there any merit in adding potentiometers to vary particular effects?

    Cheers,
    Neil.

    • morganhendry says:

      You are correct that two of the pins should be ground and power. I presumed everything on the chip was operating around 5V and would be relatively tolerant to most short circuits. Here’s the thing: there is most likely a patch that could fry this unit. Unfortunately, I don’t know what it is. Circuit bending is, by its nature, a somewhat destructive act. You kind of just have to proceed at your own risk.

      • Neil says:

        Thanks, I did find the pin layout eventually using the link on circuitbenders (in the tips section) so I’ll try the address pins first and see what happens. Aprreciate the advice that the chip should be relatively tolerant…famous last words!

  6. toddalancampbell says:

    Is your best S01 for sale? Here’s hoping! 🙂

  7. toddalancampbell says:

    I meant “bent” and not “best” 🙂

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