VCO CEM problems.

[BJ]

BJ wrote:
 
 There have been discussions about power supplys here a time
 back.
 
 Are there any one that have had problems with a LFO switching
 that are make interference to a VCO module.
 The VCO are a CEM 3340, or more likely there are 3 of them on
 the same PCB.
 My design are very carefully laid out on the PCB.
 The VCO are changing in frequency wery wery slightely!
 
 The LFO have separate Regulators7805/7905 and 220µF filter
 capps.The 2 PCB's are runing from the same supply.
 The supply can deliver +/-2A.
 The VCO PCB have no regulators but 440µF on both rails.
 
 The LFO design are a basic Integrator type.
 LFO design are made with CMOS.
 
 Is this solwed with a separate supply for the VCO PCB,
 does any builder on this list run their modular system with
 separate supplys for different modules to gain for highest performance.
 
 I have tried to decoupling the boards with separate 1000µF capps, but
 the supply don't stay stable?????
 
 The Lab supply are all OK, i have made a check on it!
 
 Perhapps the CEM master have some clue?
 Asks BJ in sweden.