Newbie Studer B67 Speakr Moduler Schematic Help

[MJ]

Hi!

I need some help with an old Studer B67 Speaker Module, and am barely just started on my journey to understand electronics and schematics.

I found an old Studer speaker from a Studer B67 mix-down deck, and I want to house it and use it as a “B" reference speaker.

I think I found the pertinent pages from a B67 service manual.

I have the speaker module, I bought a 12-volt switching power supply, and the appropriate XLR jacks and an IEC power receptacle.

What I can’t figure out is how to connect it all up (the audio jacks and the power-supply)?

I don’t need to keep the Molex connectors…I can just splice or solder the correct wires.

Any help would be greatly appreciated!

 

[MJ]

 

[RuudNL]

You need two voltages: +12 volts (- connected to ground) and -12 volts (+ connected to ground).

 

[MJ]

Hi thanks!

This is the supply I bought. Is that what a switching power supply does?

https://www.amazon.com/gp/product/B078RY6YY3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[cardboard]

Dear MJ,

The Power Supply you bought gives only 'one of the two' 12 Volts you need to fire up the Studer unit.
On the Power Supply it says '-V' and '+V' and also a nice grounding symbol. These three could be mistaken for a -12V, a ground and a + 12V.
Unfortunately, it isn't.

You really need a power supply that generates two separate voltages: But I'm not sure that a 'switched' supply can do this.
I'd go and look for a preassembled kit on ebay, velleman, conrad, whatever.

regards,
cardboard

 

[MJ]

Hi thanks very much for that! I'll start looking at them and try to find the right one.

If you don't mind, what I was also trying to figure out is which wires or connections are the audio and which are the power?

I keep looking at the schematic drawings, and printed out a chart I found online that shows the common symbols for electric components so I could try to read the schematic, but (I'm completely new to this) I am still trying to figuire out how to connect the audio inputs and how to connect the power supply (once I get the correct one)?

Thanks again!

 

[cardboard]

Dear MJ,

I'd love to point that out to you in the STUDER drawings you've supplied, but their resolution is too low to decipher numbers or characters. Better one would be of great help...

cardboard

 

[lpla]

Hi all
You can download ALL the Studer-Revox user and service manuals (with high quality scans) from this web:
https://www.reeltoreel.nl/studer/Public/Products/Recording_Analog/Best regards

 

[cardboard]

OK, thanks. Nice. Now let's see if MJ loads the relevant pages up here, or I.

ps: funny to see that of the only STUDER I own, a B37, that website does not have documentation

 

[MJ]

Hi thanks!

I'll try to upload more high-res. images.

I actually had these higher-res. images before, but when I upload them I think the forum-hosting must have compressed the images.

 

[MJ]

Hopefully these will be better.

If not I may put them on a dropbox link.

Thanks to everyone who has tried to help me!

 

[cardboard]

Dear MJ,

Good that you posted readable stuff. I tried to find the relevant pages a few weeks ago, but got lost in the overwhelming sameness of all those manual pages.

Just now, I compared your very first photo with the 4 pdf's you posted today. What you have in the photo is shown in 'B67_MkII_Op_Serv_PvdM_Searchable 4.pdf': the speaker panel, with 3 buttons, a headphone jack and a volume knob.
That's nice, but there is no amplifier in your photo. The amplifier is to be connected to that white connector lying on your table, the one with one tooth missing (made it orange in the STUDER drawing)

So.... do you have it?

regards,

mart

 

[gyraf]

It looks like there is a vertical board in the picture, at an angle to the switch PCB where that connector is - containing what looks like a small heat sink.. Perhaps that one is the amplifier? It dosen't have to be all that big here..

/Jakob E.

 

[cardboard]

Dear MJ,

Jacob E. Gyraf may very, very well be very right. Black heat sink for two transistors, just like in pdf nr. 2.
So... you seem to have the power amp after all
But: Better photos, closer up, would be helpful, though.
Because if we know what we have, connection is going to be a rather joyful 3-step thing.

Preview:
step 1: connect it to two 9V batteries
step 2: source a 2x12V power supply
step 3: make it all permanent

Q: do you have a soldering iron. If not, OK too, then we'll use small teminal blocks with screws.

 

[MJ]

Hey thanks all!

I am going to put the photos I have up in a few minutes.

Yes I do have a soldering iron. Not too good at it yet, but trying hard to get better.

A friend recently gave me a lesson in soldering and some old circuit boards too practice with, which has been very helpful!

 

[MJ]

 

[MJ]

 

[MJ]

 

[cardboard]

Now that's what I call good information! Let's have good look and compare photos with pdf's...

 

[cardboard]

Dear MJ,

I took that look, and here's what I found. The two cable spaghettis originate from the two big 20-pole strips on the STUDER thing. In the attached image, you can see them twice: at the top, in all detail, and on their technical drawing, below that. You need to check if a wire is connected to pin 13. If so, free it up and use it as your 0V wire. If not, solder a wire to it. You need it. See image.

Once you have that, I think we can proceed to hooking the thing up to two 9V batteries.

M