Dc offset pop sound on solo buttons and Console status buttons

[Dave Dicson]

I'm wondering weather it might be power supply(s). With all the modules removed, I would connect 1 power supply @ a time straight into the console. No changer unit. If the pop is still there, switch to the other power supply and a different cable. Make sure there are no burnt traces on the 651 mother board or any other 651 cards.

[tlmaen]

I habe a malcom toft mpower PSU with a 4 Meter Power cable.
Just measured the voltages at the center section today to make sure they are in spec and symetrical. A major issue with the PSU is, that it cab deliver a maximum voltage if 19v.
At the center section it was only +/-17,75v.
I will change these little round connectors to proper Harting Connectors, like the neves consoles have. Think this will give me half a volt. The connectors are getting warm over time.

The traces in the center section cards are looking quite good.
Couldn find any burned traces, just some areas with a darker green than ofher cards.

Thanks,
Tilmann

[horizonsound]

The measured rails at the centre section should be 18.5V

Over a 10m supply cable, you can experience a voltage drop of over 1.0V. Even at 1.5m, I have seen 0.5V drop.

I'm actually surprised that you say the PSU has a max of 19.0V as I would expect it to be much higher.

I know that the Toft PSU takes a standard switchmode module and modifies it to limit the voltage (down from standard 24V).

Anthony.