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[darkside labs]

Apologies in advance if this would be better placed on a different forum.
I recently acquired a Canford Audio MX622 Mixer off that auction site, without the PSU. Naively I expected I might find the complimentary literature on line but have been unsuccessful (apparently, the mixer was made by a third party and thus, Canford have no information on this particular product). I don’t mind building my own PSU for it (imagining it is no more complicated than a bipolar DC supply, possibly including 48v for Phantom Power) but without even an inkling as to what the power requirements are / the plug wiring might be I don’t have a chance in hell! I’d be most grateful if anyone can supply me with any relevant information. The socket on the mixer is (I think) 8 pin DIN (I believe it’s the same connector as found on a pre-USB mouse).

[Hugh Robjohns]

If you're capable and competent enough to build a replacement mains psu, it should be equally within your talents to figure out the socket wiring. Looking at the types of ICs used and any internal power regulation will tell you the required voltages, and their number a good guide to the likely current demands.

Alternatively, Orchid Electronics (in the UK) offer to build custom mixer power supplies and may be able to help.

[darkside labs]

Sage advice as always Hugh, much obliged.

[Wonks]

The PCB may have the voltages printed on it. Then again it may not and then you'll have to try and work out the connection pin-outs even if you can guess the voltages used.

[ef37a]

The internal electrolytic capacitors are your best guide to the actual supply voltages. If 16V types (unlikely) for example you can assume 12-0-12 rails, 22V caps mean 15 or 18V supplies but if making a supply from scratch I would not exceed 17V*. For "prosumer" interfaces a 15+15 volt supply gives more than enough headroom.

The current consumption can be estimated from counting the ICs and noting the types but I doubt you will need more than one amp.

The pre USB mouse plug was PS2 (waaaaay ago kbds were 5pin DIN) and they were 6 pins. If at all possible I would change the connector for XLR or 9 pin D sub. Even if space does not permit I would grommet the hole and have a short cable with male line connector.

*D Self: "Small Signal Amplifier Design" gives several 17V schematics and a way to get limited capacity phantom power. Might be easier to just make a separate 48V supply with a suitable transformer?

Dave.

[darkside labs]

The internal electrolytic capacitors are your best guide to the actual supply voltages. If 16V types (unlikely) for example you can assume 12-0-12 rails, 22V caps mean 15 or 18V supplies but if making a supply from scratch I would not exceed 17V*. For "prosumer" interfaces a 15+15 volt supply gives more than enough headroom.

The current consumption can be estimated from counting the ICs and noting the types but I doubt you will need more than one amp.

The pre USB mouse plug was PS2 (waaaaay ago kbds were 5pin DIN) and they were 6 pins. If at all possible I would change the connector for XLR or 9 pin D sub. Even if space does not permit I would grommet the hole and have a short cable with male line connector.

*D Self: "Small Signal Amplifier Design" gives several 17V schematics and a way to get limited capacity phantom power. Might be easier to just make a separate 48V supply with a suitable transformer?

Dave.

Many thanks Dave for the most helpful pointers. I have to disassemble the entire enclosure in order to gain internal access, I may be some time!