Name:    Steve Kennedy
Email:   st3eve@pacair.com  
Subject: MM-hd130
Thread:  9
Time:    Wed, 01 Mar 2000 17:26:59 GMT

Since I didn't have a Music Man amp open for inspection, I looked through some of my MM Catalogs.


In a mid-70's catalog, I found ONE picture which barely shows the internals and there does indeed appear to be a turret board in there for the phase splitter components (less tube).


While I work on amplifiers and do all my own repairs and modifications, I have never had a reason to repair a Music Man in this area so the driver board is sort of a mystery to me!


While I am not in a position right now to open up my amplifier and document its interior for you, perhaps someone else is? I had intended to do this for the web page, but it is one of those things I have to have the time to get into!


It appears to be a board the size of the solid state driver, but has only passive components on it. The tube is chassis mounted, as it the Master Volume control. All the passive components are on this board.


It looks to me as if a proto-board with turrets and hand wiring would work as a replacement with no problem as long as you use good quality wire and construction techniques.


The only question I would have is what (if any) passive components in this cusrcuit should or must be wired at the tube on the back of the socket. Most of these parts are on the driver board itself from the looks of this poor photo.


The photo in question is really bad for finding any information out on this subject. It is a production line photo of a women doing final ssembly on a chassis, taken from a low angle of view that barely peaks into the chassis of the amp she is working and shows almost no detail but does confirm the presence of the driver board assembly in the tube phase-splitter version.


Steve