Ampeg GT10 Xsistor part number
:) Greetings, I am working on a GT10 Amplifier. There are two output transistors, one a TO-3, and the other a TO-220. The schematic inside the unit shows pictures that these are the correct case styles for these outputs.
Someone replaced both of these with NTE replacements.
NTE 121 for the TO-3 and NTE 196 for the TO-220.
The TO-3 is shorted. I cross referenced the 121 to a 2SB407, (both are germanium).
The TO-220 tests good with my Fluke 87, and it is Silicon.
As Elmer Fudd would say, "Theres something Scwoowy going on here".
I also have a paper schematic of my own and looking at the base to emitter voltage drops indicate both should be Germanium.
I replaced the NTE 121 with the 2SB407, missing voltages came back
but there is still no output and before I go any further I need to find some good cross references for the original Ampeg numbers.
The schematic has the original Ampeg part numbers for these transistors.
REF. Part # Case Type NTE thats in there now
Q10 610289-1 TO-3 PNP 121
Q11 610289-2 TO-220 NPN 196