Siemens Regie und Steuerpult

[nashkato]

Hi
I came across this small (70ies ? )Siemens Mixer .
Penny Giles Faders , Haufe transformers , TBA221 Chips

Unfortunately missing the Powersupply .
Anyone got some documents , information whatsoever ?

 

[PRR]

The chip is a '741 work-alike.
https://www.semicon-data.com/pdf/SHS/TB/TBA221.pdf

Likely power would be single 24V or bipolar +/-15V.

Figure 3mA each chip plus another 3mA for any chips which might drive 600 Ohms to high level.

If there are lamps or relays, they may pull more power than all the chips together.

 

[mjrippe]

Everything that I have seen from Siemens of that vintage was indeed +24v DC.

 

[nashkato]

yeah , 24 Volts is what is written on the 3 fuses on the most right panel .
What might be more important are the connections on the back .