Last weekend I landed another free synth from the local used music shop I frequent. I found a case that I need for another one of my synths and stumbled upon this Yamaha DX-21 that had a $10 price tag on it. The tag said the DX-21 was broken with no sound coming out. I asked the clerk about it and he said that the power worked but that it then freezes with the “Yamaha DX-21 Synthesizer” message on the LCD screen. Plus there is no sound. As a result of buying a case, he decided to throw in the Yamaha DX-21 for free as he didn’t think he could sell it broken. He asked if I wanted it and I said sure thing! I didn’t know a whole lot about the Yamaha DX-21 but I thought it would be fun to try and fix it.
When I got home I anxiously cracked open the Yamaha DX-21 and notice right away that the battery needed to be replaced. In fact, the battery was already starting to leak but nothing had reached the PCB board yet. I desoldered the battery and then soldered in a new battery holder as a replacement. I then did some quick cleaning of the contact areas and some parts of the PCB board that looked a little dirty. I finally put everything back together and fired up the Yamaha DX-21. Sure enough it turn on by using the reset procedure which is holding down buttons 1 and 2 while powering on the synth. The Yamaha DX-21 entered test mode and then I could proceed to load the internal ROM patches back into the 32 Ram voice slots. Everything worked perfectly and so I was excited to basically get a fully working Yamaha DX-21 for free.
The Yamaha DX-21 surprisingly is a great little 4-OP FM synth. It has single and dual modes which allows you to layer or split the keyboard. There is LFO editing, portamento, and a nice sounding chorus effect built in. The body is is very strong and the keys play nicely. It can be a tad bit noisy, but I really feel it adds to the character of the DX-21 and so I welcome the noise it makes. In fact there are some internal presets that really sound cool with a little noise mixed in. It’s all about one’s preference, but I actually like having noise mixed in with FM sounds rather than having them perfectly clean. The Lo-Fi sound of the Yamaha DX-21 is really cool and it’s been fun jamming with it today. The Yamaha DX-21 is a great find I think and definitely a keeper.
Here’s a demo of the Yamaha DX-21 in action found on Youtube.