Yearly Archives: 2019

Pedal Board Project

I don’t often use guitar pedals, but they are good for creatively messing up the ‘clean’ sounds from my synths. It was always a bit of a hassle setting them up though, and as you know I like a project, so I put together a basic pedal board. All fairly standard stuff, but I introduced a mini mixer in the chain so that I can mix the wet and dry signals from the delay. It also allows me to create some feedback loops by using output B from the reverb and putting it into Input 3 on the mixer.

My requirements were also that they should be powered off of a single plug. The pedals were straightforward in that regard, but the mixer used 12v rather than the 9v pedal’s typical need.

The solution came in the form of the Donner DP-2 Guitar Pedal Power Supply, which has 10 outputs including one at 12v. The included power lead didn’t fit the socket of the mixer though, and I also needed to invert the polarity too, so had to invest in a couple of adapters which did the trick!

Some cable ties helped to control the rat’s nest of wires underneath and I added some castors too. Originally, there were 4 castors, but I decided to remove 2 of them so the board tilts at a nice angle.

The photos look a little wonky, but that’s just the angle of the photo – they are square, honest!

Korg DDD-1 LCD

So the good news is the Blue LCD I bought on ebay is fully compatible with the Korg DDD-1! The model I went with is the HD44780, although it has slightly different dimensions to the original, so I had to get a bit creative with attaching it to the case. I also had to extend some of the wires from the circuit board so they could reach the solder points.

Unfortunately, my excitement was short lived as I managed to kill the backlight within a few minutes as the voltage was probably too high.

So, after ordering another replacement (Yellow backlight this time), I decided to put an inline resistor on pin 15 to reduce the voltage. A quick google suggested something around 47 ohm should do the trick, but the smallest resistor I had to hand was 100 ohm.

I’m happy to report it all works fine though, and with no annoying whining sound!

I’ve also replaced the main navigation / cursor buttons which are a lot more responsive now. The back-up battery replacement was a bit fiddly, but I’ve done that too 🙂

Interestingly, the HD44780 was also the model I used on my Akai S2000, but that’s working fine without an inline resistor!

Hello again!

Hello again, it’s been a while! The last 18 months have seen me buy a new house, move in, move out again, then pretty much rebuild it.

We are finally getting back to normality though, and I now have the luxury of a dedicated studio space in the house (no more shed at the end of the garden!).

Whilst unpacking my equipment, I decided it was time to give some TLC to some of my more aged items.

Korg DDD-1 Drum Machine

Korg launched the DDD-1 drum machine in 1986. Built like a tank, it’s sounds have arguably aged better than competitor drum machines of the day such as the Roland TR-505 and Yamaha RX series. You aren’t limited to the 18 onboard sounds either, as it has 4 rom card expansion slots and Korg released a large number of expansions which pop up from time to time on ebay.

It also has an optional sampling board but these are very difficult to find, not to mention cost prohibitive on those rare occasions when one comes up for sale. More usefully though, an enterprising individual has reverse-engineered the rom cards and built an adapter that lets you add your own sounds, stored on EPROM chips.

I have a couple of these adapters myself, and have started burning my own EPROM’s with sounds created on my modular system. Of course, as the DDD-1 is only 8-bit, the samples don’t sound exactly the same as the originals, but this only serves to make them more unique.

Time for surgery

I purchased my DDD-1 a couple of years ago, and it generally works fine, but does have a high-pitched whining noise which I suspect comes from the LCD backlight. This isn’t present on the audio outputs though so is something I’ve largely learned to live with.

More recently though, I’ve noticed that the selection slider is a bit temperamental and the plus and minus selection buttons need quite a hard push before they work, which makes it difficult to program. Being over 30 years old, there’s a high probability the back-up battery will soon fail too, so I’ve decided some surgery is in order.

The back-up battery is your usual CR2032 button affair, although in their wisdom, Korg elected to solder this on the board. So I’ll also be fitting a battery holder to make future maintenance easier.

I’ve also noticed my Akai S2000 display is becoming fainter too, so will probably replace the LCD on that too at the same time.