late 1970s Auditronics Grandson 110B 4-Bus console rebuild

[zzzzz]

Proud new owner of a late 70s Auditronics Grandson 110B 4-bus console. I use the term “console” very loosely.

Over the past year, I've been servicing and upgrading an early Grandson 110-8 at a studio where I occasionally track. I’ve rebuilt several of their channel strips and built them a new PSU from the ground up. Recently, the owner of the studio asked me if I wanted his “spare console,” and of course I said yes. Now, I have a dream come true & simultaneous total nightmare on my hands.

My plan is to use this console mainly for mixing and very light tracking in the B Room at our studio.

Obviously, it needs a TON of work to the point of being mostly a rebuild. However, I guess this could be viewed as an opportunity to reconfigure the console to my liking... I made a black market ad for things I am searching for: https://groupdiy.com/threads/wanted-auditronics-grandson-110-input-modules-other-spares.89039/

Here's a link to the service manual with all schematics for a slightly earlier version of this console: https://groupdiy.com/threads/auditronics.51783/page-2#post-1169981



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BIG THINGS:

• Missing ALL INPUT MODULES HA HA HA… so I’ll indefinitely be hunting for them. Anyone here have any leads on spares? They can be in varying degrees of functionality as I know my way around the circuit pretty well at this point. I’d obviously prefer the “classic” 110 IME with inductor EQ, but interested in others just so I can get the show on the road.
  
  
• I already have many of the spares (not pictured) required to fill in the blanks for all of the routing modules on the top row and routing modules in the middle row, which is nice. Unsure of their functionality and some are missing transformers among other parts. HOWEVER, I am still missing the SM Studio Monitor Module but this isn't a huge concern.
  
  
• No patchbay or external Molex cabling but that’s okay. I’d want to reconfigure the routing anyway and plan to use DB25 cabling. Most if not all of the underside wiring seems intact.
  
  
• No backplane motherboard for the A-30 line output cards which I am SURE will be impossible to source. (the A-30 is not unlike an API 325 but with an IC plus a transistor output stage v.s 2520)
  
  
  
  All cabling was chopped for it, but I do have the document of how it would have been hooked up. I had already planned to rebuild the master output section anyway, either using something like the CAPI 2 Channel ACA Booster project or a Neumann V475-2B amp (I already own that but was using in a different project).
  
  • Since I don’t have the backplane, I guess I don’t even need to use A-30 cards for outputs, and I only have two of them. I’m thinking it’ll be easier in the long run to rework the output section from the ground up and disregard the stock setup.
    
    
  • I previously created a PCB layout for API 325-style line amps in a "universal" configuration (project page here on the forum) which could be adapted for this. Additionally, using THAT line drivers could be more effective for utilitarian applications like echo sends where A-30 cards would typically have been used.
    
• No legs or hardware. Bottom plate is gone too. A local friend is an excellent woodworker so he’ll be getting some work from me.

 

[zzzzz]

And here I was thinking I'd never track one of these down! Huge, massive thanks to @nielsk for the help.

I now have *almost* everything to get my Grandson console up and running and passing signal which is pretty cool. Other than wiring, of course.

Still looking for spare input modules (ideally with EQ) and a SM Studio Monitor module!