Hi all

I've got an old Tapco Mix 50 mixing desk which I used to use as a mic pre-amp and as an amplifier for my electro-acoustic guitar. I want to use it again, but have long since lost the power supply. I would rather replace the PSU if possible than buy a new desk, so I'm hoping someone here might be able to help me identify the connector used on the PSU to I can either buy a whole new PSU, or buy a connector and wire up my own PSU. The company which manufactured the desk is no longer in existence, and I can't find a spare part for the desk anywhere.

I've attached a photo of the PSU connector on the desk itself. The internal diameter is approximately 8mm. There are three pins, two of which I believe are 18.5v. There is a small notch at the top of the connector which served both as a key to ensure correct orientation, and also prevented accidental disconnection. There is a small button on the barrel of the connector which, when clicked down, will allow the plug to be removed.

If anyone needs any more information please let me know. Hopefully somebody will recognise the connector and be able to direct me to where I might be able to find a replacement.

Thanks in advance!


(Thumbnail, click for full size)

 

It may just be easier to replace the connector.
https://goo.gl/images/VWEPqH

 

It may just be easier to replace the connector.
https://goo.gl/images/VWEPqH

Thank you! It's good to know the name of the part and that I can replace it. The problem now is that I don't know the pinout. The top side of the PCB isn't visible, as the bottom panel exposes the underside, and revealing the top side would require removing all the knobs of the mixer to release the PCB from its housing. If I do that though, I can get the pinout and then wire up a new supply from a replacement connector. Thanks again!

 

See page 14 in the linked document, which says the input is 18.5Vac x2.

http://www.hobosound.com.tw/pdf/TAPCO/MIX 120.pdf

The connector looks like a GX12 (of sorts)

https://www.ebay.co.uk/itm/10-Set-G...nnector/361769444461?var=&hash=item543b23a46d

 

See page 14 in the linked document, which says the input is 18.5Vac x2.

http://www.hobosound.com.tw/pdf/TAPCO/MIX 120.pdf

The connector looks like a GX12 (of sorts)

https://www.ebay.co.uk/itm/10-Set-G...nnector/361769444461?var=&hash=item543b23a46d

Thank you. I hadn’t seen that document. Its a shame it doesn’t show the pinout for the connector so I could determine which is ground and which are the 18.5v, as that would have meant not having to dismantle the whole thing to find out. But I think at this stage that’s my only option.

 

There is a good chance the 0V center tap will connect to the chassis somewhere. Try measuring the resistance to chassis from each pin.

 

There is a good chance the 0V center tap will connect to the chassis somewhere. Try measuring the resistance to chassis from each pin.

Thanks dendad. The chassis itself is not conductive (perhaps due to its powder coating), but this did give me an idea. The metal housing of the power socket itself registers 8 ohms of resistance to the bottom-most pin, and the other two register no connection at all. Would it be safe to assume, therefore, that the bottom-most pin is 0v? Furthermore, when I replace the PSU, do I need to isolate the two 18.5v lines, or can I just connect them in parallel to the same output of the replacement supply?

Thanks again!

 

Probably the audio common or shields will be connected to the 0V too.
But it sounds like it will be ok.
The two 18V windings need to be the ends of a center tapped 36V winding.
On the transformer, it is usually marked "18V 0V 18V".
So, no, you do not connect them both to the same 18V wire.
I am partial to this site..
http://www.learnabout-electronics.org/
And here is the center tapped transformer circuit.
http://www.learnabout-electronics.org/PSU/psu11.php