AMPEX MM1200 Help.

[Chrome Heart]

Can anyone tell me how to adjust the MDA card in an Ampex MM1200? I have the manual but when I follow the procedure I dont get any readings on the scope where Im supposed to. It seems like R15 and R16 are backwards? It just aint sinking in.
TIA

 

[bruno2000]

We had 2 1200s in the Remote Truck, and I can remember just enough that we had to mod and beef up the MDA in order for it to work right with modern power transistors.  IIRC we put in a lot of caps, and MOV's.  Does your machine have the "constant tension" mod?
Best,
Bruno2000

 

[Chrome Heart]

Thanks Bruno. I dont see anything on the MDA that would indicate a mod. It follows the component layout as it is in the manual. I have just rebuilt the MDA since the trimpots were corroded and Im trying to get the settings correct.

 

[Biasrocks]

Can't be much help for your current situation.

I have the complete Record Plant mods for the MM1200 here in PDF, along with another document which has some mods I can send over.

PM your email.

Regards,
Mark

 

[Chrome Heart]

Thanks Mark. PM'd