greenhouse_hum
Member
Hello DIY Friends,
I recently came across an old CCA Ultimate 10 Stereo Console from the 1970s that was left for dead as radio technology went digital. The console chassis, and most internal components, are in fine condition – so I’ve decided to make a project of it. My dream is to combine some of the original engineering concepts, with some added modern designs and functions using the original chassis, to create a custom 10-channel summing mixer.
I have the entire manual for this console (block diagrams, schematics, parts lists, etc). In the coming months I hope to upload all of that information for posterity, and in the process pick your collective brains on how to bring this little gem back to life in 2024 – 54 years after it was pressed into service.
The first schematic I am uploading today, and pinning to this initial post, is the original Line Amplifier for this unit. I’m gathering it only works for a mono source, not stereo, and has a UTC A11 in line as the input transformer, an Op Amp Labs 425, and finally a Altec 15356 as the output transformer.
Do you folks have any suggestions on how to improve this design, or should I leave it alone?
I believe I will need 10 of these line amp channels – each tied to an XLR input – that when in service will feed rotary potentiometers that’ll account for volume adjustments, as well as pan pots for stereo imaging. The original console had Altec pots and no pan function, but I guess that’ll be post #2 after I get a handle on what to do with this line amp section.
Thank you in advance for your time in reading this post, and talent in the form of any ideas you may provide for discussion. I am excited to share this process with all of you!

I recently came across an old CCA Ultimate 10 Stereo Console from the 1970s that was left for dead as radio technology went digital. The console chassis, and most internal components, are in fine condition – so I’ve decided to make a project of it. My dream is to combine some of the original engineering concepts, with some added modern designs and functions using the original chassis, to create a custom 10-channel summing mixer.
I have the entire manual for this console (block diagrams, schematics, parts lists, etc). In the coming months I hope to upload all of that information for posterity, and in the process pick your collective brains on how to bring this little gem back to life in 2024 – 54 years after it was pressed into service.
The first schematic I am uploading today, and pinning to this initial post, is the original Line Amplifier for this unit. I’m gathering it only works for a mono source, not stereo, and has a UTC A11 in line as the input transformer, an Op Amp Labs 425, and finally a Altec 15356 as the output transformer.
Do you folks have any suggestions on how to improve this design, or should I leave it alone?
I believe I will need 10 of these line amp channels – each tied to an XLR input – that when in service will feed rotary potentiometers that’ll account for volume adjustments, as well as pan pots for stereo imaging. The original console had Altec pots and no pan function, but I guess that’ll be post #2 after I get a handle on what to do with this line amp section.
Thank you in advance for your time in reading this post, and talent in the form of any ideas you may provide for discussion. I am excited to share this process with all of you!
