I decided to make one (1) music. It's called "Title Screen Music From An Amiga Game Your Older Brother Used To Play" because it felt like a fitting name. It's nominally synthwave but there's probably some elements of other genres mixed in too.
This was done on my Yamaha QY100 and recorded on my Yamaha MT4X. I mostly made it to serve as elevator music during less interesting parts of my videos, which I did on my latest upload and I think it works well for that.
So it's that time again.
This JX-305 came up for sale with those four sweet words "For Parts or Repair".
The seller indicated that the synth stopped working after they had played a gig on a boat, in which they were forced to leave the synth out in some misty rain because they didn't have anything to cover it with. I was quite confident that the rain had nothing to do with the failure, so I made a bid and it arrived on my bench.
When I powered the synth on, it was indeed dead as a doornail.
The display was blank, none of the LEDs were lit other than the Beat light which was glowing orange (it's only ever supposed to be red or green in normal operation), and basically everything was unresponsive. Not a positive first step.
However, much like the MC-505, which this synth is based on, the CPU has a hard-coded bootloader that you can access by holding down the right keys when powering it on.
The magic combination is to hold down "Mute Ctrl" while powering the synth on, and then tap on "3/High Hat" a few seconds later.
Well that's looking better already. Let's see how far we can get with this.
Well, it's taking data, and...
Hmm, nope, no good. Well, that explains why the main processor isn't booting: if it can't write a firmware image it sure isn't going to be able to read it back either.
Having a peek inside, we can see some big flat-pack chips soldered down with our good friend lead-free solder.
This one in particular is the flash chip that holds the firmware, and I think it needs a little love. So, come along for the adventure and see where it takes me!
I promise it'll be fun. Or, well, it was for me at least.
My XV-5050, being a moderately modern ROMpler, contains quite a few samples of quite a few instruments.
The Roland ROMplers from this era take "SRX" expansion cards, which include a bunch more instrument samples, plus presets that arrange these samples into a set of tones to form a patch, including information about what effects to apply, what sort of envelope to use to shape the sound, and so on.
The XV-5050 in particular has two SRX slots, which you access by removing a cover from the top panel. You can even see the huge Roland DSP in the corner there whose leads had lifted off the solder pads, which I had to reflow to get this unit working again.
Anyway, the SRX cards themselves are basically just a carrier for a set of mask ROMs, which are the large chips you see here.
There's also a handful of passives, capacitors and resistors mostly, the connector, and two more ICs.
The smaller of these two chips is a TC7W34FU which is a triple non-inverting buffer chip. It's simply used to buffer the signals to the other IC, which is a 93LC46X EEPROM. The EEPROM is writeable from the main unit although I don't know if that functionality is used in the stock firmware. The entire EEPROM is only 128 bytes (1kbit), so it likely only contains some very basic identification and configuration information for the card, and not anything like the patch data.
Anyway, with that curiosity out of the way, let's stick it into the XV.
It's got this sort of twist-lock tab on one corner that's meant to keep it from falling out but it's honestly a bit of a pain to use. I got it in there, though, and that's what matters.
Well, what really matters is actually whether it works or not, so let's check that.
Yup, there we go. A whole world of sounds at my fingertips!
I was messing around with calibrating my 3D printer today (pro tip: pressure advance is a miracle) and while I was waiting for the test prints to print, I decided to replace the tact switches in the MPC 1000.
I really should have replaced them when I was in there the first time, but they gave every outward appearance of actually working. Oh how foolish I was to think that they would be reliably functional.
Luckily there's not that many of them and they're pretty easy to get to.
I also took the opportunity to swap in some diffuse LEDs now that my jumbo pack of diffuse 3mm LEDs came in.
This is most certainly an improvement, though it's a little hard to appreciate on camera.
The yellow and red buttons down here saw the biggest improvement from the diffuse LEDs.
The illumination is much more even, despite the camera making it look cartoonishly bad.
Anyway, replacing the LEDs and tact switches went well, thankfully there weren't too many of them to go through.
And with that, the unit is one step closer to being fully refreshed.
Though the pads themselves are misbehaving a little, so stay tuned for that I guess.
Continuing along on my effects journey, I wanted to round out my guitar signal chain with a compressor, and I picked the Boss CP-1X to do the job.
A compressor at its most core level will track the envelope of a signal, its overall volume, and when it exceeds a certain level it will turn down the gain on the signal. This compresses the dynamic range into a smaller dB window, which intuitively seems like it should make it sound like the louder parts get toned down a little.
However, what really happens is that the louder parts no longer dominate the quieter sections, and so in effect the compressor pedal lifts those quieter parts up in (relative) volume. This makes it sound like sustained notes ring out much longer, which can be very helpful if you want something that sounds more smooth and less plucky (which I often do).
But of course it doesn't just make the note tails longer, because as soon as another note gets played the envelope follower triggers the compression circuit to drop the gain again, and so new notes can essentially mute old notes, making sure that the sound doesn't get muddied up with too much happening at once.
This kind of effect works really well at the start of the signal chain, and for right now I'm thinking that this will be a good setup.
The compressor sits at the start of the chain to shape the signal coming straight out of the guitar. This particular compressor also includes an expander function where at very low volumes the compression is reversed and the gain is reduced. This ensures that background noise doesn't get amplified up into annoyingly audible levels when nothing else is playing, which can be an issue with less sophisticated compression effects.
This then gets fed into the Boss OC-5 Octave pedal which I discussed recently. I can bring this in and out depending on whether I want to play some bass lines or just guitar stuff.
Next we have the start of the tone shaping effects with the Boss DC-2w Dimension C chorus pedal. This adds a lot of depth, space and motion to the sound. It can also add stereo width, but I'll likely be running it in mono into the final pedal on the board.
The Zoom MS-50G takes up the final spot, where it will be providing a Reverb <- Amp Sim <- Delay chain. The delay effect gives a sharp echo to the sound, which can help consecutive notes harmonize together. The amp sim effect basically colours the sound in the same way that a number of classic guitar and/or bass amps would. Finally the reverb adds a diffuse echo to open up the soundstage and give the impression that the guitar was recorded in a physical acoustic environment rather than sounding like the raw audio is being poured directly into your ears.
So that's the guitar side of things taken care of, but what about squishing the rest of my sound? Well, it just so happens that I came across a Boss RCL-10 from their Micro Rack series.
This one is set up a little differently from the CP-1X. Rather than having a compressor and expander that work simultaneously, it instead has an overall control that allows you to dial in compression if you turn it in one direction, or expansion if you turn it in the other. It then has a separate noise gate which sharply cuts off the input when the volume drops below a certain level.
In practice one can set up the RCL-10 to act very similarly to the CP-1X by dialling in the main circuit for the desired level of compression and then tuning the noise gate to cut off just before any background noise is picked up.
But that's not the only thing you can do with it. Since the noise gate is separately configurable, you can also do silly tricks like feeding a reverb into it.
This causes the compressor to drag out the reverb trail until it reaches the noise gate threshold, at which point it gets sharply cut off. This was very characteristic of a lot of 80s drum sounds, and once you hear it you'll realize you recognize it in a lot of songs of the era.
Now, did I buy this compressor for that purpose? No. Well, maybe a little bit. I actually bought it because it was a really cheap Micro Rack effect in good condition, and in particular it still had the button caps on the power, effect and, around back, the input gain selector switch.
And I wanted a good example to be able to model and 3d print some replacements for my reverb unit.
Which is, you know, another future project to add to the pile.
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.
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.
