The Cash Register

The AKAI MPC is one of the foundational pieces of hardware in the hip hop music scene, basically taking over from record players, pause tapes, and earlier samplers, taking off in the 1990s and continuing to this day. It became so ingrained in the production workflow that it became nicknamed "the cash register" due to how much money was made with it... and also because the original units like the MPC 60 looked uncannily similar to actual cash registers of the time.

While the original was mostly just a sampler and basic sequencer, the modern MPCs have turned into an all-singing, all-dancing full studio-in-a-box workstation, and that excess of functionality and flexibility had somewhat turned me off the idea of ever getting one. If I wanted an "anything machine" I could just open up my laptop and fire up Logic Pro.

But then, as it happens, a cheap MPC 1000 popped up for sale in a bit of a sorry state. It had two redeeming features: firstly that it predated the explosion of music workstation features that have come to define the modern MPCs, being essentially still just a sampler and sequencer, and secondly it was cheap.

So, as these things go, it found a new home with me.

I could tell in the listing that this unit had a few things going for it. It obviously has the aftermarket pads installed front and center, which almost everyone will insist is a mandatory upgrade. The screen was working perfectly, which is a bonus as it's a common failure point. Finally, it was clear that someone had upgraded the firmware to JJOS, which is a $123 (as of this blog post) unlock.

But with the upsides came downsides, like the fact that every single key cap on the unit was broken.

And it was filthy.

And it was, let's say, customized.

So first things first, let's clear out the shrapnel of the old key caps.

Thankfully the tact switches underneath are fine, despite the grime they're swimming in.

And before I go putting things back together, I'm going to need to clean the case. Most of it is just a job for soap and water, but this sticker residue would need a more invasive treatment.

Isopropyl alcohol would cut through it pretty quickly, but a test in an inconspicuous area revealed it would also cut through the paint, which wasn't ideal.

Instead, I decided to try cleaning off the glue with ammonia.

Did it work? It sure as hell did.

There's not much I can do for the moment about the lost paint though, but I might come back to revisit that at a later date.

Now while the screen itself was in good shape, I couldn't really say the same about the clear cover.

I've certainly seen worse scratches, but this still called for some intervention.

I gave it a good polish, along with the rest of the cover while I was at it, and while it didn't take out all of the scratches, it certainly improved things by a lot.

Anyway, I got a new set of aftermarket key caps to replace the shattered originals, except that for whatever reason they don't make the purple direction key caps, instead substituting a boring off-white.

Luckily the original purple key caps were still in good shape, save for one that had a small crack in it.

A little super glue should hold it together... I hope.

And if not, I can always see about maybe painting the 4 spare key caps I have left over from the new set.

And speaking of the new set, let's get them in place.

But hmm, that's odd, I seem to have too many clear key caps and not enough of the off-white. I was just putting the off-white ones in wherever there wasn't an LED to shine through and...

Well isn't that peculiar, one of the LEDs is missing. What's even more strange is that, looking at the back of the board, it seems like it was never there to begin with. The solder pads look factory fresh and completely untouched.

It's peculiar that in all these years, since it was born into this world in 2003, nobody has bothered to drop in a simple 5-cent LED.

Well I certainly won't let that stand, so in goes 4 new LEDs: one to replace the missing one, and three more to make the rest of the Bank A/B/C/D buttons match. I figured that would be enough, the LEDs would probably be close enough that I wouldn't be bothered by the ones elsewhere being a bit different.

So there's just one final task remaining, which is to fix the feet. Two were missing, and the remaining two were kind of worn.

So off come the tired old feet, and the sticky glue residue, and on go the new replacements.

And then it all goes back together.

It's still far from perfect, but it's a huge improvement over how it arrived. I no longer feel compelled to wash my hands after every time I touch it.

And let's have a look at those new LEDs to see how well they blend in with the old.

Oh. Huh. Yeah that's quite different, isn't it? Amusingly, the new LEDs are so much more efficient that even the ones that are turned off are slightly visible with a faint glow.

Well, only one thing to do I guess.

Ok well at least they all match now. The only thing I'm a little put off by is that I only had clear LEDs instead of the diffuse ones, so the buttons are less evenly lit than they should be. I might go back in later and replace them again once I pick up some diffuse LEDs, since they're pretty easy to get to, but that's a job for another day.

In the meantime, I now need to learn how to use an MPC 1000.

Switching Things Up

So recently I got the urge to actually make a little music. For reasons I may or may not explain in a future blog post, I decided to use my MC-505 to do the job.

I probably should have grabbed my QY100 instead, because as soon as I powered on the MC-505 I was reminded that I still definitely needed to replace the main key switches for the sequence/keyboard buttons along the bottom. They were double-triggering whenever I released a key, which was really not helpful for trying to make music, as you might imagine.

So, apart it comes.

The black switches with the grey silicone domes are the culprit. They sit underneath the black and white plastic "keys" and do the job of actually being a switch. The silicone rubber dome makes them a little more squishy and mostly silent compared to the usual clicky tact switch, which is appropriate for this function in a musical instrument.

Anyway, I happened to buy a whole bulk bag of replacements from some mysterious source in the far east, so in they went.

I put everything back together and powered the system on and to my delight the triggering was now very solid with no bouncing and multi-triggering. Unfortunately I was reminded of the two OTHER reasons that this box was still sitting in the repair queue: the 8 main part mixer sliders were rather dramatically misbehaving, and the main jog wheel encoder was barely functional.

I'm pretty sure both these issues can be solved with a little careful disassembly and cleaning, but that task would have to wait for another day. First, I needed a little break to touch some grass.

Mmm, greenery.

Anyway, since the MC-505 still needed work I grabbed my MC-303 and set to work hammering out a tune.

This lasted for all of about 3 seconds before I remembered that it too needed a new set of key switches. Well, I've got the soldering iron warmed up so let's get to it I guess.

Much like the MC-505 this involves removing literally every component in the entire system. But then it's out with the old...

And in with the... also old? You see, I'd found a source for some new-old-stock switches that exactly matched the originals in the MC-303, and I wanted to try them out.

You can see the new, NOS and original switches lined up here from left to right, and the difference with the new switch is pretty plain to see.

It would still probably work, but there was one issue with the new switches that was giving me pause: the contact resistance.

Here's the new switch when pressed.

100Ω is pretty trash tier for most switches, but for a carbon pill switch without any additional coatings to improve conductivity it's kind of par for the course.

So let's compare that to one of the original switches.

It's a bit on the high side, but 3Ω is an order of magnitude lower resistance than the candidate replacement. This wasn't too much of an issue on the MC-505 since its original switches were reading more in the 100Ω-ish range too, but something felt wrong with replacing a low resistance switch with a high resistance one in the MC-303.

The NOS switches, despite being 30 years old, were obviously built different from the new switches.

That's more like what I expect to see from a switch that's working properly.

But that leads us to another problem, which is that these switches have been lingering around for 30 years, exposed to the atmosphere, humidity, and so on, and that's taken its toll on the leads.

Solder isn't going to stick to that black, sooty oxidation no matter how much heat I use. So I need to scrub it back to clean metal with a wire brush first, then tidy up with some isopropyl alcohol. Here's a little before-and-after.

The leads were still a little disagreeable when soldering them but I think I managed to get a solid joint on most of them. I wouldn't be surprised if at some point down the line some of the solder joints fail, but that's a future-me problem. For now they're all working reliably.

And after all that I still ended up using my Yamaha QY100 instead.

Red and Sticky

So recently I came upon a fantastic find, a Roland D-50 listed for sale at an absolute bargain price with those four little words I love so much: For Parts or Repair!

Wait, wait; actually my bad, this is the Roland D-70, the much loathed and resented synthesizer that was based on a completely different line of synths, and only gained the D- prefix when Roland realized that people really loved the D-50 and decided that phoning in a follow-up would be a really great plan.

It was actually the bridge between the Roland U-20/U-220 (and can even take the same expansion cards) and the later JD-800 in terms of lineage, and other than a few notable faults (like an underpowered CPU that can bog down under high load leading to slower than usual ADSR envelopes and LFO modulations, and the sound structure where tones are shared between patches) it wasn't a terrible synth. It just wasn't a D-50, a crime for which it will never be forgiven.

Anyway, that's really neither here nor there. This one is mine now, and it needs some fixing, so click through the break to read more.

If I Had A Nickel For Every Time

I got a few new bits of gear added to the pile recently, and both were half-rack modules, both produced no sound, and both, curiously, suffered from a shorted aluminum electrolytic capacitor which is a very unusual failure mode.

First up, the Boss RRV-10 Reverb. This reverb unit has a delightfully crunchy 12 bit sound to the echo signal which makes it honestly kind of an amazing effect. But it won't do me any good if it's dead, so it needs some fixin'.

Next is the Yamaha FB-01, which is a 4-operator FM sound module. It's mostly notable for the SolBass preset, but it has some other nice sounds in it. Or, at least, it would have other nice sounds if it wasn't just spitting out nothing but hum and noise. So it gets some fixin' too.

You might be wondering why it looks like the FB-01 has a black hole on its surface. The reason is pretty simple: at some point someone decided that it needed to have a sticker, and then at some later point someone decided that it needed to not have a sticker. That latter person scrubbed pretty hard to get the sticker and its residue off, and left a bit of a ring in the paint.

I hit it with some car polish and got it looking a lot better.

The remaining ring is much less visible but still there, and I can't really fully get rid of it without polishing the whole case to a high shine, which would look kind of out-of-place, so I'm leaving it like this.

I did at least take off some grime while I was doing that polish.

So that's a nice bonus.

April Showers

Wait, why is it raining in April? Well, no matter, the wet spring is at least being good to my plants.

Most of my plants, that is. This sage that I planted in the front last year got immediately attacked by some kind of flies that loved chewing on the leaves. I was hoping that applying some insecticide might knock them back enough for the plant to out-grow their damage, but they didn't really manage it before the chill of winter set in, and while only one of them properly died, the other two were looking like pure ass and so I decided to ditch the lot of them and start over with something else.

After all, I can't exactly use the sage leaves in cooking if I'm constantly drenching them with insecticide.

In their place I decided to plant this sunpatiens. I'm hoping they're more patien than sun, since they're being planted on the north side of the house, but I guess we'll find out. They were in the shade section of the nursery so if this goes wrong I'll blame them.

And if they do die, you can write this variety down on your list of plants to not buy.

Speaking of dead plants, most of my lantana made it through the winter. One, however, did not. This trend is at least heading in the right direction.

So it's out with the dead and in with the live.

I went with a purple variety this time to see if it might be more hardy and for a bit of variety and definitely not because the nursery didn't have any of the confetti variety that I've been planting in prior years.

I guess we'll see if I just wasted $15. It should at least look nice for the summer.

Out, damn spot, out!

So a while back I managed to get a few tiny drips of red latex house paint on my blue shorts. I didn't notice them until after they had dried, at which point it seemed to be too late to remove them. Most methods of removing paint involve high heat, which would melt the fabric, harsh chemicals, which would melt the fabric, or scraping with a sharp implement, which would melt shred the fabric.

However, by chance I was cleaning a mark off a door frame this morning when I decided to try a little rubbing alcohol to loosen the smudge of dirt. It did loosen the dirt, as well as the paint underneath it. Oops!

But that's when inspiration naturally struck: the fabric of my shorts won't be affected by the alcohol, and yet latex paint clearly will be. This called for some science.

Well I'll be, it worked. But science is worthless if an experiment can't be repeated, so let's try another spot.

And the verdict is...

Success!

It took quite a bit of scrubbing with the alcohol to get the paint to fully vanish, but the important part is that I got there in the end.

Hot Lead

So I decided that today was a good day for some Saturday night soldering. I've been sitting on this Relatively Universal ROM programmer kit for a while, and I figured it was time to put it together.

All of the itty bitty SMD components come pre-soldered, and it's just the headers and the ZIF socket that need to be tended to.

For no reason other than"I felt like it", I went for the ZIF socket first.

The Arduino headers came next, and I used an Arduino as a jig to hold them in the correct orientation.

And the programmer goes on top, ready for soldering.

Once the ends of each pin header strip are tacked in place, I can take it off and do the rest of the soldering without the Arduino underneath.

And that looks a little something like this.

A few more bits get soldered on the other side. A L-shaped jumper thing near the ZIF socket arm, and a header for an OLED screen that I don't actually have but should maybe probably get.

Plugging it in reveals that things are basically functional, so far as I can tell without a ROM to plug into it.

Of course just having raw PCBs sitting on whatever surface I place this on isn't really the most ideal situation, so I'll go ahead and print out a low-profile case for the Arduino. This marks the first time I've ever printed a downloaded model, so let's hope it goes well.

While that's going, I have some tact switches that need to be replaced in a synth which I am not acknowledging the existence of because I haven't finished repairing it yet.

It's out with the old...

And I forgot to take a picture of the "in with the new". Well, just pretend it looks like the picture previous to this one, but with newer looking switches.

All told, I replaced quite a few switches.

57 of them to be exact.

Which makes for 228 solder joints that were desoldered and resoldered.

And just in time, the print is done.

As I expected from looking at the model, some of the overhangs and bridges didn't print too amazingly well.

But a bit of trimming with a hobby knife cleaned things up well enough to work.

And the ROM programmer still fits on top.

So I'll call that a success, and another project checked off the list.