Saturday, February 19, 2011

The Autogram AC-8 is well on its way to being up and running.

My intent is to situate the AC-8 as master summing console in the studio, freeing up the other desks for branch/sub-mixes or abuse, depending on unit and project. This was a weak attempt at trying to induce some sort of saturation, I don't think I got anywhere near the headroom threshold. The Program/Audition outputs offer support of two independent stereo pairs.

Here's the input/output connectivity block. The good people at Autogram have uploaded user manuals for this era of gear here: this goes a very long way in clearing up what is what. Pictured is channel 3A input (red wire) and Program output.

I've pulled all the active stages per channel out (slotting those into the AC-6) and populated all the stereo channels with 1:1 600 ohm interstage transformers. I believe this means that the functional block above is the only active electronics each channel passes through.

Schematic for the MXA-1 mix summing stage is above and the LA-1 line amplifier stage is below.

These stages share PCB artwork, clearly there are only minor differences between the two. Since I have the luxury of having a complete quartet of spares (sitting in the AC-6) I'm thinking about rebuilding these stages, upgrading components where I can and eliminating redundant or unnecessary parts (the caps on input/output for example). As it stands now though, the desk is super quiet and full sounding and justifies the 38 by 20 inch footprint it consumes.

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