KORG POLY800 / EX800 'POLYBEAST' MODS: £75 (installed)
The Korg Poly800 and its rackmount / tabletop cousin the EX800 are odd beasts. They came from that strange era of Korg synths where they couldn't seem to decide between analogue and digital, and so came up with a selection of hybrid synths that didn't seem to excel as either sound. On paper the Poly800 was a pretty well endowed machine but in reality it always sounded a little thin and never really fulfilled its potential, which is where we step in with our Polybeast mods!
the mods consist of 3 main sections, Filter mods, FM mods and audio mods.
FILTER MODS:
Cutoff & Resonance Knobs: This mod can be found around the net under several different names and versions but essentially it adds knob controls for the filter cutoff and resonance parameters for realtime control. The resonance knob can take the resonance well into self oscillation and far beyond what is programmable from the front panel. This can produce the kind of screaming top end and subsonic bass that gives these machines a whole new range of sonic possibilities. The filter cutoff knob allows you to perform long filter sweeps for those squidgy burbling analogue lines that you knew your Korg was capable of but could never actually program. Both parameters are still also controlled by the normal programming methods which can set the range of the knobs control.
12dB / 24dB Filter Response Switch: Somewhat mysteriously the filter chip used in these machines has both 12dB/Oct and 24dB/Oct outputs but only the 24dB one is actually used. This mod adds a switch to select either a 24dB or less drastic 12dB filter response
VCF CV input: This socket round the back of the machine adds an external 0-5v control voltage input that controls the filter cutoff. The new filter cutoff control knob is disabled when a jack is plugged into the socket.
AUDIO MODS:
External Audio Input: This accepts a line level audio signal and inserts it before the filter and chorus effect so you can use it to process external signals. The input is set up so that a loud signal will slightly overdrive the filter for a dirty sound.
Input Level Knob: Its a knob that controls the level of the audio input. What more can we say?
FM MOD'S:
These consist of a source selection knob and an FM amount knob. Essentially VCF FM allows you to modulate the filter cutoff at audio frequencies to create all kinds of clanging cross modulation and bizarre alien splatters & sweeps. This effect works best with the resonance cranked up into self oscillation which is where the new resonance knob mod comes into its own. The source selection knob allows you to select one of four sources for the FM signal. These are DCO1, DCO2, Noise and audio input. The audio input takes its signal from before the input level knob so you can use the audio to mudulate the filter cutoff but remove the actual audio signal from the mix. The source knob also has an off setting.
The EX800 version features exactly the same mods as the Poly800 and can produce exactly the same effects as for any real purposes it is exactly the same machine internally.
 |
 |
Click below for mp3 demos of these mods from both a Poly800 and an EX800.
Korg Poly800 / EX800 backup battery mod: £20 / £10
Early model mk1 Poly800's do not have a memory backup battery and so unless you keep a full set of charged batteries installed at all times the program memories will be lost when you switch the machine off. This mod simply adds a small lithium cell backup battery that keeps the memory intact when theres no power source. If there is no original battery the mod costs £20
If your machine has a backup battery but it still loses its memory the chances are that the battery is well beyond its reasonable lifespan and is completely dead. For £10 we can replace the backup battery in a battery holder that allows for easy replacement in the future.
If you want your POLY800 / EX800 modded get in touch using the CONTACT form.