Studiomaster 162BPX audio mixer

[Kingell]

Hello
First post.
Can anyone help me in finding a service manual/schematics etc for the Studiomaster 162BPX please?
Kind regards

[Mark Black]

Hi Kingell, welcome to the place.

Apparently Studiomaster has no real presence here in the USA, but they do have quite a dealer network in the UK. Since that mixer appears to be a current product (with probably very limited release of service information) your best bet might be to contact some of the dealers listed on the Studiomaster site. Studiomaster Pro Audio Equipment

Wishing you luck...

[oc disorder]

Hi Kingell

Studiomaster schematics are a bit scarce.
While you are possibly following Mark's advice I found an old site "wanadoo-members.co.uk/studiomaster"
which has schematics for the earlier model the 162BP and have been saved by the wayback machine.
Surprisingly , some of the PDF's are still alive....!

I am assuming the schematic may be similar to the one you are looking for and guessing the "X" signifies
built in effects.

Anyway may be helpful until you can get the correct diagram.

Current Products Service info

The only file that is missing from what I can see is the electrical parts list.
These seem to be all here.

Studiomaster 162BP.
Mono Mic Input T8A1
Mono / Stereo Input T8A5
Left Output T8A2
Right Output T8A3
Monitor Output T8A4
Power Supply R7A6

A.C. PSU Schematic
Mechanical Parts
Internal Wiring Diagram

[Jazz P Bass]

Cool find.
10 to 1 the X indicates a DSP FX module.

Otherwise, probably the same.

[Steve L]

Studiomaster Schematics

These may be of some help:

Studiomaster Pro2 163, 203 Schematics.pdf
Studiomaster 6-2-1 Mixer Schematics.pdf
Studiomaster Mixdown Classic 8 Schematics.pdf
Studiomaster Trilogy 166, 206, 326 Schematics.pdf

Steve

[Kingell]

Well done.

What a great set of guys!!!
Many thanks - on other forums you often have to wait days!

I've looked at these and the fault appears to be on the monitor board.
Unfortunately the schematics are different.

I persuaded Studiomaster in the UK to send me a set which they did immediately.
I've got a very strange fault on the OP where turning up the headphones makes the LED display turn up too!!
And there's no headphone audio out on the board. The Main outs are OK.
T8a4a is the headphone out where I have the problem.
Studiomaster were as baffled as I am!

I've replaced the OPAMP - 4556AD and I can't see why the LEDs are lighting.

I've tried to attach the schematics which someone else might find useful.
I don't know if I've succeeded.

Any ideas anyone?
Thanks again. Well done.
T8a1-2.pdfT8a2-2.pdfT8a3-2.pdfT8a4a-4.pdfT8a4b-4.pdfT8a5-2.pdf

[oc disorder]

I have one eyed dear.
That ⅛ watt resistor looks a bit light on for a headphone ground return
particularity for a seasoned sound guy mixing a punk band!
R3 found on T8a4a-4.pdf

[Kingell]

I have one eyed dear.
That ⅛ watt resistor looks a bit light on for a headphone ground return
particularity for a seasoned sound guy mixing a punk band!
R3 found on T8a4a-4.pdf

Hi
Thanks for the tip. I'll check it out.
Regards

[Kingell]

Hmmm
Replaced R3, C1, C2. Still got the problem.
Regards

[Jazz P Bass]

I see that you have posted the same query on another forum.
In that statement, you say that the headphone level control , turned up, illuminates the LED display.
Without a signal coming through the mixer.

Is this statement correct?
Without a signal?

[g1]

I think if the problem were coming through C1,C2 the level control should not have any effect.
It must be coming backward from IC1, then the level control can have an effect. Maybe some kind of feedback loop.
Make sure you have good grounds for the level pot and the + input pins of IC1.

[Kingell]

"In that statement, you say that the headphone level control , turned up, illuminates the LED display.
Without a signal coming through the mixer."
Yup.
That's correct.
Headphone up - LEDs also. Replaced R3 checked ground connection.

[Kingell]

Make sure you have good grounds for the level pot and the + input pins of IC1.

Many thanks for the suggestions.

I've just discovered an error in the patch on the back of the flight case. It wasn't there previous to this fault.
The microphone screens (earthed to chassis) were linked to the screen of the monitor out. (not earthed to chassis!) (Split in the cable!)

I've corrected it but the fault remains.

Still checking through. I'm now fitting a socket so I can replace IC2.

Many thanks for the suggestions and help. Much appreciated.

No imminent gigs but I'm getting worried. I might have to buy a stand-by!

Kind regards

[Jazz P Bass]

This makes no sense.

IC1 voltage readings would help.
I have a feeling that pin 1 & pin 7 are going high.
The reason for that is not clear.

Make sure that pin 3 & pin 5 of IC1 connect to R3/ non chassis side.

[Kingell]

Yup - I'll check that - thanks very much.

Thanks for the pdfs - I've already got them all for all the boards and ICs.

Now I've got this IC in a socket I should be able to read the voltages.
It was very difficult with the position of the board before.

Thanks again for your support. It all seems very puzzling.
Finding that short on the patch panel might make a difference when I get
it all back together.

Got 10 days to the next gig. I might borrow a mixer if this is still puzzling.

Kind regards