Hi salomonander,
sorry for the off-topic..
It is some months that I'm curious about the mute/solo circuit of the 169/269 Studer consoles.
Too bad some weeks ago I've stupidly failed to do a test on the added Q8's distortion (for its Rds-on non-linearity) in my 269.
I've made the measurements pre and post Q8-Q9 on an input module, but forgot to isolate the channel,
by mean of detaching the jumper from 41 (PP1-12) to 40 (PP1-11) in pag 143 of 169/269 service manual,
or panning to the other bus all the other channels, or pulling out the other input modules,
[edit]or, of course, bypassing the JFETS stage with wire(s)[/edit].
So, in THD+N and noise-only "post" measurements the risk is that I was seeing/hearing also some hiss from the other channels
[I dont remember, but its possible that all the channels were panned to the same bus, and faders not down].
Now I dont have the console here, hope to redo soon the test correctly.
More on topic:
I'm not sure if you have tried the circuit with the JFET(s) in series, shunting, or both (like in the 169), nor if you've tried it only with the linked java simulator or with real components..
and.. what is the "audio" that you've connected to "audio out" of your first drafts, when it was not the (working) LED?
sorry for the off-topic..
It is some months that I'm curious about the mute/solo circuit of the 169/269 Studer consoles.
Too bad some weeks ago I've stupidly failed to do a test on the added Q8's distortion (for its Rds-on non-linearity) in my 269.
I've made the measurements pre and post Q8-Q9 on an input module, but forgot to isolate the channel,
by mean of detaching the jumper from 41 (PP1-12) to 40 (PP1-11) in pag 143 of 169/269 service manual,
or panning to the other bus all the other channels, or pulling out the other input modules,
[edit]or, of course, bypassing the JFETS stage with wire(s)[/edit].
So, in THD+N and noise-only "post" measurements the risk is that I was seeing/hearing also some hiss from the other channels
[I dont remember, but its possible that all the channels were panned to the same bus, and faders not down].
Now I dont have the console here, hope to redo soon the test correctly.
More on topic:
I'm not sure if you have tried the circuit with the JFET(s) in series, shunting, or both (like in the 169), nor if you've tried it only with the linked java simulator or with real components..
and.. what is the "audio" that you've connected to "audio out" of your first drafts, when it was not the (working) LED?
