Presonus Studiolive AR16 USB mixer.

[MikeCross]

I have been given a faulty Presonus AR16 USB Mixer.
The power supply has failed and some of it's capacitors have exploded.
Not being a fan of switch mode supplies I would like to build an external supply for the unit.
Can anyone please supply me with a circuit diagram of this mixer or provide me with the voltages used within it's circuits.
I did find one connector with pins marked as +- 12volts.
When applying these voltages the audio circuits worked but the Effects, Phantom power AND USB sections failed to operate.
So I guess I am missing a couple of other power rails.

Many Thank
Mike

[jamesperrett]

Phantom power will need 48V (unless it has some other way of generating 48V from another rail). Logic will probably require 5V but may possibly need 3.3V.

[Radio Wrangler]

You'll also need to know what current each voltage rail takes in order to size the supplies needed.

David

[JonSnell]

If you remove the faulty power supply, an XP POWER AHM150PS24 24V, 6.25A, 150W, Desktop Power Supply (Medical), IEC C14, 4 Pin Plug will fit in as a replacement.
I repaired one a few weeke ago and CPC supplied the power supply.
They use 24volts as phantom power. No need for 48v as anything north of 12volts will work.

CPC part number is PW04492
I was going to fit a 4 pin DIN on the chassis and have it as an external supply, but upon removal of the old supply, a large tywrap and the replacement fits snugly.
Wire a right angle IEC plug to fit the existing mains connector and from the outside, it is original.
The power supply is up to medical standards, so should be good for years to come.

[MikeCross]

Hi Jon
Did the unit you repaired only need the single 24v power rail?
On the unit I have there is a 9 pin flat cable between the power supply board and the motherboard.
The pins of this cable are labelled as follows
1 Gnd
2 no label
3 and 4 -12v
5 and 6 Gnd
7 and 8 +12v
9 no label.
Pin 9 does not connect to anything as far as I can tell.
When I apply the +- 12v each takes about 450ma and the basic audio channels work with led displays working.
The effects function, USB and Phantom power does not.
It suggests to me that pin 2 would be the missing supply? I have several bench supplies which I could try. Any suggestions of voltage ?

[JonSnell]

The Presonus I repaired required a single 24volt supply that connected to a sub board to split the supply to whatever was required.
I was lucky. I had a clue, upon removing the power supply, printed on the board was 85 - 250v AC to 24volts 120Watts, so easy for me.
I would suggest your missing voltage is either 3.3volts or 5volts.
Any clues on the old power supply?

[MikeCross]

Further close inspection of the components feeding voltages to pin 2 suggest it is +5v
and pin 9 has 65v capacitors suggesting it is the 48v phantom power.

So unless someone has any other suggestions I will try these voltages and stand back.

[jamesperrett]

Does it use a normal switch to enable phantom power? If so, you could enable phantom power on a channel and then check the resistance between pin 2 or 3 of one of the mic connectors and pin 9 on the PSU cable. You should see 6.8k if it conforms to the normal phantom power standard.

[JonSnell]

I think you have it there Mike.
The power supply would apear similar to most of the Allen & Heath types.
The models I have repaired are the Bluetooth only versions, used on live stage productions, where the mixer has all or the XLR and other input sockets, an A-D convertor that controls the whole network (similar to using Audacity) and then sends the whole signal from all of the varios controls etc through Bluetooth into the receiver that converts the signals into analogue for multi channel amplification through the front of house and monitor PA systems. They all have a virtual mixing desk for your iPad to control.
I have had great success with SMPS repairs as long as the transformer is OK and spares are available, I am happy to take the power supply in for a repair.
May be easier than trying to make one up.
However you could consider;
https://uk.farnell.com/solahd/scp30d...o-p/dp/1387968
a 5volt tap with a simple regulator may suffice if you know the power requirements.
As for the 48v a buck convertor on the +ve rail should suffice as it is low current.
You may wish to surf fleabay for some Meanwell supplies. https://www.ebay.co.uk/itm/162799417...BlBMUJSnpomOYg

[MikeCross]

Just to let other owners of this model of mixer.

My thoughts were correct and I now have a fully operation Presonus.

Thanks to all others that helped.