Tube numbering convention for ST-70

[rockable]

What is the tube numbering system for ST-70's. I know that guitar amps are V1 on the right and the numbering progresses to the left. I have no clue of what Dynaco used. Thanks.

[burnedfingers]

Facing the driver board. Rectifier is V1, El34 closest to rectifier and or the output transformer is V2, and V3 is closest to the driver board on that side. Other side (right) is V6 by the driver board and V7 by the choke or power supply capacitor. V4 and V5 must be the 7199's. I would guess that V4 would be on the left side as you faced the driver board but I cannot tell from any picture I have found so far.

[Bob01605]

Rockable,

On the ST-70 V1 is the GZ34 rectifier tube

V2 and V3 are the two LEFT channel tubes output tubes - V3 is the tube closest to the FRONT of the chassis

V4 is the LEFT channel 7199 and V5 is the RIGHT channel 7199 tube.

V6 and V7 are the two RIGHT channel output tubes - V6 is the tube closest to the FRONT of the chassis

The power takeoff sockets as far as I know were not given a number.

Check the link listed below for the original ST-70 pictorial with some wiring colored in by me.

http://i9.photobucket.com/albums/a78/Bo ... r_1024.jpg

Bob Latino

[rockable]

Thanks, guys!

[rockable]

Bob, isnt's the + end of the bias caps supposed to be grounded?

[mesherm]

In the pictorial, the + end of the bias caps appear to me to be grounded. There is a wire from the terminal strip the + ends are soldered to that connects to the center of the dual 0.02uf ceramic cap and then runs on to the common ground lug.

[rockable]

I eventually saw that. Thanks!