This particular drum machine is a favourite of mine to bend, as its results are phenomenal! In this project I decided to utilise a patch bay, as it allows full use of the bends instead of permanently wired switches to certain points which limit the users control. Most of my projects use patch bays as you’ll notice, but that just personal preference. Once inside the machine, you’ll find its pretty sparse, which always helps in finding bend points, but all the safest bends and connections are made on two chips.I’ve decided to re-write this page to make it a bit clearer for everybody since i keep getting asked for schematics, which i don’t have, as I’ve not produced any, sorry.
:::DISCLAIMER:::
CIRCUIT BENDING CAN BE DANGEROUS. I ACCEPT NO RESPONSIBILITY FOR DAMAGE TO YOUR HEALTH OR YOUR MACHINES IF YOU ATTEMPT ANYTHING I OFFER BELOW.
DUE THE AGE OF MOST BENDABLE OBJECTS, THEY CAN SOMETIMES BE ON THEIR LAST LEGS AS IT IS, SO TINKERING WITH THEM IN THIS FASHION AND PROBING AREAS YOU SHOULDN’T CAN PERMANENTLY BEND THEM OR KILL THEM UNEXPECTEDLY, RESULTING IN A LOVELY RETRO PAPERWEIGHT. I OFFER NO GUARENTEES THAT WHAT WORKS FOR ME AND MY MACHINES WILL WORK PERFECTLY FOR YOURS.
YOU HAVE BEEN WARNED.
CAUTION: TAKE CARE HANDLING THE PCB EVEN WHEN NOT CONNECTED TO THE MAINS POWER SUPPLY, THERE ARE SOME LARGE CAPACITORS IN THERE THAT COULD/WILL HURT YOU! I AM NOT RESPONSIBLE FOR YOUR WELL BEING.
1) Take your HR-16 and flip it over. Take out all the screws. There should be 4 of them, a nice easy one to open. Put the screws somewhere safe, a bowl is handy.
Seperate the top and bottom cases. You’ll find that the top is connected by a few jumper wires. these have plugs on one end to make it easier to dismantle. just remember the polarity of the jumpers for when you reconnect it later, however if you need to test your bends first, its easier to leave them connected so you’ll still have button functions while testing.
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2) The PCB we want is located in the bottom half of the unit. Again, you need to remove the screws to access the underside of this PCB. You’ll notice that this contains all the chips, capacitors, jack sockets etc. It’ll look like this, but without the blue wires….
The top half has all the button and display PCB’s in it. Theres not much of interest in the top section unless you need to clean sticky buttons.
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3) Taking the bottom PCB, you need to locate the two horizontaly mounted IC’s (chips), everything else is vertically mounted. They are located right behind the TAPE IN/OUT and OUTPUT2 jack sockets and infront of a a square chip and a small battery. The chips have 32 pins each, count them if you have to make sure you got the right ones.
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4) The two chips seem to be idenctical in function for bending purposes. I have no idea why but they must contain the same data and perform the same functions, but this makes the machine even easier to bend, as you dont have to worry about soldering every pin on one chip. You can stagger them for ease across both chips.
Remove the PCB from the case. flip it over and find the 4 rows of pins from the two chips underneath.
Take you test cables, run a pattern in the drum machine, and start connecting 2 pins from either of the two chips together to create bend points. I’ve found there are very few combinations that will stall the machine, and i’ll try and dig out my notes on the ones that do. Play around and see what does what, you might like to take notes so you can groupcertain types of bend effects together later on. The more you understand the better.
Remember the points that you’d like to hard wire switches (or anything you like) to, or, if you are the control freak that i am, and love a bit of hard work, you can take them all for a patch bay.
The easiest option for bends like this is to use ribbon cable, i prefer rainbow cable as its easier to identify the strands than the standard grey and single red ribbon cable you get, however at the time i didnt have any so settled on single stranded wire.
Remember to prepare and tin the ends of the wire first, its much easier to solder this way. It’s a good idea to measure how much cable you need for one, stretching from where the final resting place of the PCB will be, and snaked through the inside of the machine to the point where the wire will be connected to the front panel, and cut identical lengths. Measure twice, cut once, its easier, and you’ll thank yourself one day….
CAUTION: ALWAYS DISCONNECT FROM THE MAINS POWER SUPPLY BEFORE SOLDERING ANYTHING!
I settled on a 28 way patchbay, mainly because this would fit my front panel design, so i needed 28 pins from the two chips to be soldered. The end result looked like this, notice the staggered pin soldering across the two chips. By this, I mean every second pin is soldered to a wire, and alternated on the second chip so we have all 28 different pins that we needed.You’ll notice a salmon coloured wire on the left photo. this was there already, and is a PCB revision, if yours doesn’t have it, its not going to be an issue for this project.
In this formation i end up with 14 pins on each chip, 7 on each side, being connected to as bend points.
Solder 3.5mm mono jack sockets (or banana sockets) to the end of each of the cables connected to the pins on the chips, as per below.
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5) Now we have to build the front panel. I went for a 28 way patchbay, with a switchable 3 or 6 way multi point bay, and 6 patch switches for on/off switching of the bends connected to the switch. These switches have indicator LED’s which arent needed, but I have an LED fetish, and their blue…
Take the top section of the case, and remove the flip up lid. Unfortunately i have not found a way of removing this with out breaking its hindge. the plastic is too rigid to bend far enough with out snaping. Remove the instruction lable on the inside. this is stuck down with some heavy duty adhesive, and rubbing alcohol might be needed to remove the sticky bits left behind…. I say “might” but this has always been the case for me.
I find the easiest way to plot out the holes is to draw them on graph paper first, then cut it out and lightly stick it to the inside with a minimal scoosh of spay mount. if you do it on the inside, it doesn’t matter so much about getting it off, but remember to invert your design. double check you get it right, as once you start drilling theres no going back!
My patchbay sockets, switches and LED’s are all mounted in a 15mm pitched grid, with a 10mm boarder from the edges of the case to allow clearance of the sockets and jacks. The only downside to this is that there is one large capacitor inside that obstructs the first patchbay socket of the second row from the top, and the jack plug cannot be inserted fully. This can be over come by re-positioning the capacitor on its side, just remember to discharge it first, or by omitting that socket altogether, or, just leave it as it is, put a few layers of electrical tape on top of it and promise yourself not to push anything into that socket too hard for fear of piercing the capacitor and regretting it for the next few milliseconds before death rocks up in the happy bus to take you to your new eternal home, where ever that maybe.
Remove the PCB’s and sliders from the top case before drilling, as destroying these now would be a real let down.
Using the now stuck down paper grid as a guide, drill all the holes you require, making sure they are straight and are of a suitable size for the components you are using. I find that a piece of wood underneath gives something to press against and stops the case from warping, and protects whatever surface is underneath, such as your mums nice new carpet or wooden flooring…. Thankfully I have a studio in the house so my wife doesnt care as long as the mess stays in there. Any electric hand drill will be suitable for plastic cases, but i recently invested in a nice pillar drill for such things and PCB drilling.
Here you can see the patch bay in the upper left of the panel, the 3 or 6 way multipoint bay underneath and the (unfinished) patch switches on the right.
This picture shows the inside view of the above, notice the jumper cables that were disconnected. the length of the bend point cables in this unit were a little long in retrospect, 50mm or so could have been trimmed off each, but you can see how much is required to enable easy mounting and installation of everything.
Once everthing is secured in place, re-connect the jumper cables from the front panel to to bottom half, test everything and seal it up, remembering to screw the bottom PCB back in place.
The patchbay is used by taking 3.5mm patch cables and inserting into the bay. This will connect two points of the chips that we probed, tested and soldered earlier. When a pattern is running or midi data is being received, the two connected bend points will cause an effect/bend to be generated.
To use the switches, a cables is patched from the bay, to the upper socket above the switch. another point of the bay is connected to the lower socket. When the switch is flipped, the two sockets are connected, thus completing the link between the two points of the bay and allowing you to have presets as such.
Below the bay are two sets of 3 sockets, with one switch between the two. Each set of three sockets are connected together, allowing 3 points of the patch bay to be connected for even more sonic mayhem! The switch in the middle connects the two sets, allowing them to be used independently, or combined to give up to 6 simultaneous connections. The bends generate all manner of effects, such as distortion, flanges, ring nods effects, filtering, sound swapping and muting. Some even generate synth like sounds.
The first sample here is a combination of 3 bends toggled on and off in sequence to the beats, as is the second sample, but different bend points. I added a bit of reverb, which makes the synth sounds stand out more, other than that, no external processing was done. The input connection on my old imac was a bit loose it would seem, so there’s some additional crackling in the first sample that doesnt come from the machine. Both use the same drum loop, to show the huge variation in sounds available from the bends.
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The LED schematics for the switches are a whole other story, and i’ll cover them in another tutorial at some point later, as the same principle can be used for alot of different machines. Here’s a photo of the inside, notice the use of double pole switches to allow seperate cicuits for the bends and the LED’s.
September 16th, 2007 - 4:19 pm
nice work, blue leds are a great choice. Thanks for stopping by, we will post a photo of it.
October 9th, 2007 - 3:02 am
do you have any pdf or jpegs of your bend? I’m trying to make a hardcore drum machine for my industrial group. I dig the sound of your design alot.
please respond.
easleyrz16@aol.com
muses bless
~Z~
October 9th, 2007 - 12:40 pm
Alright Z? check your email, i’ve sent some useful information for you.
cheers for stopping by!
bod.
October 23rd, 2007 - 9:47 pm
Hello.
This is really nice work. I’ve presently got my HR16 in pieces, ready to be bent. I think I’m going to build a breakout box for it though, as it’s my first bending project and I don’t think I’m up to drilling the case just yet…
I have a question for you if you have a minute: what’s the salmon coloured wire that’s soldered to the underside of the PCB?
Thanks.
-Ian
October 25th, 2007 - 8:49 am
hi ian, the salmon coloured wire is some sort of jumper wire that was installed by alesis. i think it was a revision to the PCB, and instead of designing new boards they merely just put this jumper in. its meant to be there, don’t touch it…. ;o) if yours doesnt have it, then don’t worry, you’ve probably just got a slightly older machine.
break out boxes are certainly easier to build, it was quite tight for me to get all that in there, and one of my jacks actually hits the large capacitor on the left hand side, i had to reposition that. any way, good luck!
cheers for stopping by!
October 25th, 2007 - 1:59 pm
Thanks for the response. The wire is not present on my PCB. I figured it was probably a revision as you said, but just wanted to check it wasn’t another bend point that I was missing out on.
All the best.
-Ian
November 8th, 2007 - 1:06 am
Z here again, I was able to get my Hr16 working again.
also you had said you sent a schematic to me via email, but I never got it. if you could resend it that would be great.
thanks for the assist as always
muses bless,
~Z~
November 19th, 2007 - 6:32 pm
Hi there, I’m currently in the middle of bending my hr16 but I can’t seem to find a reliable source of rca jacks or 3.5 jacks. Do you know a good place to look for these items? thanks a ton
~ian
November 21st, 2007 - 7:35 pm
hi Ian, i normally use rapid electronics in the uk, dunno where you are based though. 3.5mm mono, switched jack sockets are 11pence each, or 6pence each per 100. far cheaper than the likes of maplin!!! the only small problem with rapid is the minimum order of £25, but if you are buying a load of switches, sockets or IC’s for a couple of projects then its not an issue.
i do have a load of sockets and jacks spare actually, so if you don’t want to commit to their £25 order then i can sell you whatever you need at cost price plus postage. i bought 500 of each and have 100/200 left.
Z, i resent that that the other day as you know, but have some more pics for you to send tomorrow.
cheers,
bod.
November 21st, 2007 - 7:35 pm
sorry, rapids website is at http://www.rapidonline.com/
January 2nd, 2008 - 6:40 pm
Hey man lost your email
want to say, I was FINALLY able to bend my HR-16. So far all that has been done are the first 31 patch bays + 1 switch, and they sound GREAT!!!
next I’ll be finishing up with the last 6 patch bays and the control knobs. I have to admit, I’m a little nervous about the last stuff. Kinda afraid of cooking my Alesis.
again thanks for all the help you’re giving me on this project.
muses continue to bless your inspiration,
~Z~
January 3rd, 2008 - 9:15 pm
Hello again,
I got all the bend points soldered up, spent about an hour mashing up the sounds, and went to bed very pleased with myself. Switched it on the next morning and it’s dead. The screen doesn’t flash the boot-up message, I just get a steady underscore character in the top-left. Have you seen this before? Do you know if there’s a way to perform a reset, or revert to factory settings on the HR 16? I’ve removed all the bend wires and this didn’t help.
I’m pretty sure I’ve fried it, but I live in hope. Any suggestions gratefully received!
Best,
-Ian
January 5th, 2008 - 4:24 pm
Cool, glad that i could be of assistance to you both!
Z, as long as the bend points all work ok, and by that i mean you’ve gone through every combination and it doesnt crash or get stuck, then the pots and switches won’t make any difference to the machine, as they merely control the bends. but then, as Ian has just experienced, these things dont always go smoothly! i think you’ll be fine though.
As for your dead HR-16 Ian, thats puzzling! Dont throw it out though, there could be hope for it yet.
When you were playing with the bends, did you disconnect them afterwards before you switched off? and if so, did the sound go back to normal when nothing was interconnected?
Have you soldered or tested any points other than on the two horizontal chips at the back of the board? i killed one by testing new points else where, i always stick to those chips now. I once killed a TR-707 which cost me £100 by poking about too much.
There is a possibility that the internal battery has decided to die. Most of the internal batteries in these sorts of machines tend to have a 20 year life span from what i’ve read on the subject. if this is the case, then its easy enough to replace it, but i don’t know the symptoms of this on an HR-16. Check out the burnkit 2600 site, those guys have a tutorial on this, it may even cover this machine, i’ll maybe try disconnecting the battery on mine and see what happens.
remember that most machines that are suitable for bending were developed in the 80′s and early 90′s, and most electronic components such as IC’s do have a limit on their lifespan…
I’ll get back to you on this one.
All the best and happy new to you both! ;o)
January 5th, 2008 - 10:37 pm
Hello,
Happy new year to you too. Thanks a lot for the reply.
The only places I soldered wires to were the two sound bank ROMS, and I avoided the first and last pins on each side, figuring these were probably power supply points. The sound went back to normal when no wires were shorted out. I’ve scoured the PCB for shorts due to little threads of wire and such, but haven’t spotted anything. When I de-soldered the bend points it basically looked like it did when I first took it out of the case so I’m at a bit of a loss!
I’ll investigate the battery thing though, but I saw one on eBay which said that the battery was dead and as a result it didn’t store any patterns when it was switched off, so I suspect that problem wouldn’t have the effect I’m seeing, i.e. turning the thing into a funny looking paperweight!
I’ve not given up though, the hour or so it did work for was so much fun I’m keeping a close eye out for a replacement. (Anyone who’s flogging one please let me know!) At least I’ll have a few spare parts for my next attempt…
Thanks again,
-Ian
January 5th, 2008 - 11:31 pm
That is odd. i asked the guys at burnkit so we’ll see what they think about it. fingers crossed that its repairable!
Aren’t they are great machines for bending though?!! Out of everything i’ve bent they are my favorite!
January 9th, 2008 - 11:02 am
very interesting.
i’m adding in RSS Reader
January 19th, 2008 - 4:10 pm
ian, i heard back from the guys at burnkit, they think the cable connecting the LCD to the main board might be unplugged or connected the wrong way round. i checked it on mine and the symptoms you have with the dash on the LCD are consistant to this.
hopefully its as simple as just fiddling around with the connector for the LCD, the 3 wire one i think, but see what happens.
good luck!
bod.
February 20th, 2008 - 3:01 pm
Hi!
Very nice job!!
I’m seeking over the net for some schematics to bend my HR-16.
Would you mind sending me some pics or schems of your bends?
Thank you.
Flavien
February 21st, 2008 - 9:58 pm
hi flavien,
i do have some pics of the chips you want to bend, but if you have an hr-16, pop it open and you see the two chips i talk about above. connect any of the pins on these chips together to create the bends.
check back in a week or so, and i’ll update these pages. i’m in the middle setting up my new mac and pissing about with quartz composer just now so everything is on an external drive for the moment. my trusty g3 imac finally died on me…..
March 5th, 2008 - 9:07 pm
Awesome work. If there is anyway you could send me additional images that would be awesome. This is going to be my 3rd project so I am still a newbie but very interested in doing a drum machine. Keep up the great tutorials!
April 13th, 2008 - 3:19 pm
im not in any “hardcore” industrial band however i love the crunchy drums, could you please give me some advanced info on this bend
if so i would really appreciate it!
thanks alot
emartransformo
April 15th, 2008 - 3:48 pm
Hi Bod,
No joy with the LCD connector… I’m still at a loss, but thanks for asking the burnkit guys for me. I’ve been outbid on three HR16s and a 16B on eBay recently, but I’m still on the lookout…
Cheers
-Ian
July 3rd, 2008 - 11:37 pm
Very good bend! Love the rhythm and bending in the first track. I just found my old HR-16 when unpacking some old moving boxes. Any possibility of sharing connection point info / schematics? Would love to put it to some good use after all these years of collecting dust.
July 18th, 2008 - 9:55 am
Scott, Elliot and Thomas, sorry i’ve not been in touch, but as you can see i’ve now given a more complete guie than the write up i had before, so hopefully this will help you a bit more with your bending quests! let me know how you get on.
cheers,
bod.
July 24th, 2008 - 3:26 am
Hi Bod- an excellent project and (crucially for folks like me) an excellent tutorial to accompany it- many, many thanks! I’m quite the newbie when it comes to this sort of stuff and I’ve circuit bent a few keyboards (including a couple of patchbay mods) but have tended to avoid drum machines because i’m scared of trying to bend anything which plugs into the wall. I have no real knowledge of electronics see, and well, I want to make sure i’m not dead. Could I ask what your thoughts/hints/tips are on avoiding death (in a circuit bending context- not just generally..) as you’re evidently good at it. Also, because I’m dead poor at the moment my chances of obtaining a HR-16 are probably pretty slim- are you aware of other drum machines which can be bent in a similar way and is it somewhat of a universal concept with drum machines (I’m asking because I know the FM-track cut modification for Yamaha keyboards is transferable for several models… & I can only hazard a guess that perhaps many different drum machines work in a fundamentally similar way to each other)? Once again a huge thanks for the time and effort invested in the tutorial, best regards, Jon.
July 27th, 2008 - 10:00 pm
hi jon, thanks for the feedback! thats a lot of topics to cover! and maybe a fair few more pages worth of gubins, but i’ll give it a go.
when bending anything mains powered, you should always check what voltage its running at, DC currents at 12volts or less will generally be safer, but if you don’t know dont touch it!
although, if the unit comes with a plug in wall adaptor then all the nasty converting, from deadly mains AC 240volts, is taken care of there, so the tip of the power jack you plug into the unit, is at what ever its converted to, in our case, we want it to be a nice, safe DC voltage, not that ANY voltages are safe, but just less dangerous…. if you die, dont blame me.
if you’ve bent a few keyboards then you can bend a drum machine! lots of good drum machines to bend are expensive, upward of 50 quid anyway. but you can get a cheap-ish tr-505 off of ebay. these things are a gold mine of bends, and very forgiving in my experience! I’ve done a few in the past, but i’ve got one sitting aside to use for another page.
with drum machines of a certain age (1980′s, early 90′s), you find most of the good bends are based around the rom chips, and will normally result in pleasant sounding bends, but never say never… ;o)
Probing too much in the wrong places can result in killing them, and i’ve rendered a beautiful tr-727 useless in this manner before, which was almost heart breaking!
hope this helps a little, and if not, just ask.
cheers, bod.
December 5th, 2008 - 8:35 pm
Hi! I am making a Bent HR-16. Can you tell me where you take the power for the switch’s LED? I don’t find any point + or – on the PCB. Did you take the power directly from the 3,6 V internal battery? Thank for your answer.
December 5th, 2008 - 8:50 pm
hi jeremy, cant remeber the exact point, but if you have a multimetre, check the IC’s for the power pins and steal the power from there!
December 6th, 2008 - 7:58 pm
Thank for your answer. After a looking on the IC, i found the vcc (+) and the ground. They are on the pin 32 (+) and the pin 16 (ground).
December 7th, 2008 - 3:12 pm
sweet, cheers for the info jeremy, it’ll come in handy for others, and safes me opening mine up again!
i’ve never had any issues stealing the power supply for LED’s from the power pins of the IC’s, and to be honest any of the IC’s will suffice for this, just make sure to test them first, as not all the chips have the same pin formations.
and make sure to use suitable resistors for the LED’s.
feel fre to post a link to your finished machine mate! i’d love to see it.
cheers,
bod.
March 30th, 2009 - 7:19 pm
Hello, I recently acquired an HR16 drum machine for fairly cheap and am interested in bending it. I have read your tutorial and it seems fairly straight forward, however I dont have any experience with actually bendhing electronics, although I have read about it. Is there any valuable information NOT listed here that I shoudl know before trying to do this? I dont think im going to make the patch bay, just going to try a few bends out using switches. It seems fairly straight foward. Any advice or am i in over my head?
March 31st, 2009 - 9:37 am
hello, well, advice for a novice? depends on how much experience you have with soldering really. if you’ve never soldered anything then i would suggest practicing first, maybe buy a cheap electronics kit from maplin or radioshack, depending where you live. that way you can get a grasp of how to solder first beofre attacking your hr-16. you wouldnt want to ruin it regardless of how cheap you got it.
the hr-16 is a fairly easy machine to start with though, there are only two chips to select bends on, just dont go digging about other places or you could kill it, perma-bend it.
the best advice i can give you is to practise first, either with a kit like i talked about above or some cheap toys from the pound shop. learning to solder is key imo. also, always have everything you think you’ll need before starting. like switches, solder, wire and a few tools. dont probe about near the psu source/connector, and dont touch any large capacitors.
just using switches for your first is always a bit better, there is less work involved compare to a patch bay, and since a lot of the bends can sound the same, you can select your favourites to hard wire in with switches.
let me know how you get on, and feel free to ask anything.
cheers,
bod
April 12th, 2009 - 8:23 am
Hello,
I guess I’m a little stupid, but can you tell me where the lithium battery is located? My HR16 won’t hold any memory after I shut it off. I was looking for something that looks like a watch battery, but I don’t see anything close to that. Thanks.
April 12th, 2009 - 11:31 am
not at all mate, the battery in the hr16 is a barrel battery with axel connectors, its the pink thing in this photo…. http://www.flickr.com/photos/8841838@N07/2676035575/sizes/o/
hope this helps, but i dont know a suitable replacement. try farnell or rapid, there will prob be something.
cheers
bod.
April 11th, 2010 - 6:43 pm
Great job! Thanks so much for the tutorial. I just got an HR-16 myself along with an EPROM reader/programmer and a UV EPROM eraser. Those two chips you are connecting the patches and switches to are the EPROM chips – they hold all the sounds the Alesis HR-16 makes. It used to be a pain to write new songs onto the chips (hand preparations for each new sound and a bit of hex editing and the use of a sound editing program), but a fellow by the name of Jan Kiefer wrote a program for windows (in VB I believe) which makes this process much easier. Maybe I’ll write a tutorial for the whole process. Hope to hear more from you soon.
-jacques
May 17th, 2010 - 11:56 pm
I inherited a HR-16 from a friend a few months ago. I don’t think it had it’s power supply with it and I used it as part of a sound installation with one of the dozens of random power supplies we had on hand for everything. It worked great! Now I’ve dug it out again, went and bought a power supply to fit it and have turned it on. The controls work fine, memory works fine, all the pads seem to work. The “volume” and “select” sliders are missing but i can move them around with a car key and they work fine. Problem is…. I’m not getting any actual sounds to come out. Not from the pads, not from playing the demo song, nothing, not even a click track. I’ve got the outputs running through a mixer and headphones listening in on that. Moving the volume changes my ability to hear the faint hum of the circuits so it seems to be working as volume should. Any idea what’s up? Did I kill the voice-bank or something? I’ve cleared the memory a couple times to reset it. I ran the self-diagnostic test, etc… I can do everything with it except hear what I’m doing.
-david