Korg Poly800/EX800 Users

On Wed, 2009-03-04 at 13:34 +0000, narfman96 wrote:
> Definitely timing issues with IC36b the interrupt oscillator. Try
> disconnecting the output at R107 and see if it runs at the correct
> frequency. If it does the CPU is loading it down somehow. If not then
> suspect the timing caps C76 or C79. The resistors R102-R104 need to be
> verified and then the Tl072 op amp itself. This circuit needs to run
> in the mhz or no go for the LED display and envelope generators.

Bah.  Just change the TL072 on spec.  Horrible things.

Gordon