PAiA FatMan

While looking for a synthesizer that I might be able to assemble I stumbled across the FatMan by PAiA Electronics. It looked impressive but I didn't want to spend some US$ 250 on a DIY project that might as well end in the waste basket. I shouldn't have dismissed it so fast. First, when I built the MFOS Mini-Synth I eventually ended up spending at least as much on parts and stuff. But second, the FatMan is a complete kit with all the necessary parts and excellent documentation. All in all it makes a great first SynthDIY project. I liked the look of the synth, and also needed some additional experience in Synth DIY. Their summer sale made it hard to resist, too, so I ordered a kit plus desktop case.

The FatMan is a complete monophonic synthesizer controlled via MIDI. It features two square wave oscillators that sound in tandem but can be detuned against one another up to several octaves, one VCF, one VCA, and two attack sensitive envelope generators (an ASR for the filter, and an ADSR for the amplifier).

Construction is straight forward. You start by cutting and soldering wire jumpers (actually a great way to practice your soldering skills: wires are very hard to fry... ;-), then resistors (a lot of them), then the rest in order of increasing delicacy (tendency to overheat and destruct).

The kit contains sockets only for the microprocessor and the EEPROM. All other ICs are soldered directly onto the board. I'm not the most advanced solderer, so in order to avoid overheating the more delicate components I tend to heatsink transistors using a paperclip and otherwise insert several components at once and then solder one lead of each component in a round robin way, thus giving them a little time to cool off. Mounting and wiring the panel controls was a chore, but I knew that already from the SoundLab, which had even more controls.

When I finally turned it on for what they call "smoke test" (go figure), I was surprised that the FatMan worked right from the beginning! All it required now was calibrating it to a proper octave measure. I did it "by ear" and used my DX7 to compare it with.

The FatMan has a nice warm analog sound especially well suited for fat bass lines or wild spacey solos. It's a neat little beast.