Built a custom D8B external power supply

[Carlo]

Hi, so from the pictures there are 3 power supplies replacing the
1. ATX power supply
2. Liner PS
3. ASTEC PS

can someone enlighten me what is the purpose of the ASTEC PS please? This is encased in a metal case facing the liner ps pcb.

Thanks

Carlo

Any help guys please? I've just noticed that my d8b remote pc has the two small wires coming from the astec ps to the liner psu disconnected. These small wires are colored orange and black. When i reconnected these 2 wires to the linera PS, the d8b did not boot up and instead the surface leds started to flash on and off (throbbing leds). What do you think is the problem? The previous owner might had experienced something and disconnected the wire.

Thanks
Carlo

[arjepsen]

Can you post some pictures of it - my memory is unfortunately a bit vague on how everything looked in there.

[Carlo]

https://www.dropbox.com/s/81zmxn4drap1rfu/linear%20psu.pdf?dl=0

This is the image of the wires in question indicated by a solid white arrow. The wires are seen connected in the picture but mine is disconnected. The d8b works but i'm experiencing a little movements on the faders. Its been like that since the time i bought it.

Thank you

C

[arjepsen]

Hmm... I don't recall whether mine was connected or loose.

to answer a question of yours earlier - the 3 (actually 4) power supplies are:
5V from the linear power supply.
12V from the at/atx PC power supply.
+/-16V - this comes from the transformer in there, which gets rectified and regulated on the pcb on the bottom.
This is also rectified and regulated to 48v for the phantom power (the 4th supply).

[Carlo]

cheers! thanks

[Carlo]

Hmm... I don't recall whether mine was connected or loose.

to answer a question of yours earlier - the 3 (actually 4) power supplies are:
5V from the linear power supply.
12V from the at/atx PC power supply.
+/-16V - this comes from the transformer in there, which gets rectified and regulated on the pcb on the bottom.
This is also rectified and regulated to 48v for the phantom power (the 4th supply).

So technically the ATX is responsible for the motor faders, right? Since its 16v.

But there is another PS in vertical position called ASTEC. What is it for please? Seems there are no schematics of this ps..

[Carlo]

https://www.dropbox.com/s/mzwimd49itk7sb1/ASTEC.pdf?dl=0

Im referring to this PS marked with a red arrow.
Thanks

[arjepsen]

The one that the red arrow points to is the linear psu - the one that provides 5v.
If memory serves me right, the pcb on the bottom is sort of the place where everything is connected. Both 5V and 12V are connected here, and the board also provides +/-16 volts. (plus the 48v for the phantom).

[arjepsen]

Seems memory serves me poorly......
I just checked the large1.pdf on page 102.
The linear power supply is the one providing +/-16v, but I still think that pcb is where both 5v and 12v are connected, and everything led to the umbilical. (check - seems my memory aint that good.....).

[RJH_MUSIC]

This is a great thread. I have been wanting to do this for years now. Thanks for the specs. I am going to take this one step further and build an entire new Remote CPU unit in a 2U rack chassis. Already ordered 2 Chassis for both my d8b's but going to completely build one to see if it works or not. I will have to do a fair amount of modification to the chassis to be able to get the 386 motherboard into it because it is an ATX style case.

My question here is twofold. I do not see any fuses in the pictures besides the one that is most likely in the power connector on the plug. Wondering if using the power distribution board from the d8b remote CPU will work with fuses, or are fuses not required?

Second question is, can the +/- 16V power supply handle the 48v for phantom power, or do I need a separate power supply for that.

To answer another question from Carlo a little more specifically, the original CPU has 5 components for the 4 power supplies;

1. 12V PC Power supply
2. Power distribution Board with fuses
3. Transformer for +/- 16 Rectified for 48V Phantom power and 16V
4. ASTEC LPS - 152 (Linear Power supply 5V) (this is the one that stands on it's side) (the one I have to replace every year now)
5. Linear Power supply sub assembly board

4 and 5 together make up the Linear Power Supply. At least this is what I suspect after looking at the CPU schematics. So if anyone can help, I need to figure out the 48V components and fuse integration.

RJ