Allen & Heath System 8 Mk1/2 recap and mods

[Lasselakken]

Thank you very much, Neil - it is beginning to make sense to me.

You mentioned that C8 and C9 are in series with a 22k resistor, but as far as I can see, they go directly to the next TL072?
C1 on the output cards also go directly to the op-amp - how would you estimate -3db point in that case?

 

[hwood123]

Thanks for clearing that up

I mentioned Z5U because I have a good source of these in axial form, that seemed practical. I’ll get X7R instead.

Is local power rail decoupling by the ICs generally advisable, or is it only necessary if I change to different op-amps?

Do you think I could improve anything by putting in new TL072’s, or would they perform exactly the same as the original ones from ca.1984?

Did you ever finish?

 

[hwood123]

Any one got the master and bus schematic please!!!