Dynaco ST-70 with a GSI board, Parts diagram and any info PLEASE

[Tanner]

I have a poject amp with a GSI board, It uses 4 tubes and I have very little info on this, Diagrams, parts lists anything would be of great help to me!!!

Thanks in advance

 

[llwhtt]

I have info on both of the GSI mods. The first one used 4 ea 6DJ8s in a cascode differential setup. The second used 12AX7s in a diff, with 6CG7s as drivers. The first has tubes positioned in a square as you look from the top, the second has all four in a line across the board. Let me know. Also Andy Fuchs is still around and is willing to help if he can.

Craig

 

[Tanner]

My tube are in a square formation, Thanks for the help on this project!!!

 

[Burnedfingers]

Does this look like your board?

 

[Burnedfingers]

picture

 

[Burnedfingers]

picture

 

[Tanner]

Very close but mine has the tubes favoring the right end of the board, I think yours has semiconductors in it as well mine does not. Were getting close

 

[llwhtt]

Here is the schematic of the board that 6GB6GA posted, which I received from 6GB6GA.

Craig

 

[llwhtt]

Schematic won't upload for some reason, stuck on "uploading files-please wait". It'll be there as soon as I can figure out what I did or didn't do.

Craig

 

[Burnedfingers]

schematic

Found what I have on GSI