Voltage Values Troubleshooting [solved]

[Flux Capacitor]

Checked all resistances and they were all good.

Plugged in to power and got the following values. Terminal 13 is reading 0 and B1, B3, and terminal 1 are off by more then 15%. Also one of the small LED lights (its the one connected to A8 and center terminal, orientation is correct, but does not turn on). Tubes are lighting up but I am trying to figure out what is causing the off values.

Terminal Voltage Result
1 147
2 163
3 0
4 163
5 78
6 0
7 147
8 0
9 100
10 0
11 0
12 0
13 0
14 0
15 187
20 0
21 210

A1 78
A2 0
A4 0
A5 0
A6 148
A7 0
A9 0

B1 146
B2 163
B3 148
B4 78
B5 163
B6 102
B7 0
B8 0

edit: adding some pictures

 

[Flux Capacitor]

UPDATE

I soldered many of the joints again and took down the measurements again. Resistance is good. Voltages mostly good, fixed terminal 13 and has the appropriate voltage now.

The LED still does not light up even with all joints soldered again.
A6, B1, B3 (should be 90 and I get 143-146).

Did the final check (attach tester to Tip of TRS headphone jack) to monitor the voltage when amp is turned on. The voltage went to 8.83 V and then dropped down to almost 0 (was at 0.1 or 0.2V).

EDIT: Did the final check again and it resulted in a bit better voltage with a max of 8.03 V at the Tip terminal. Goes back down to zero or close to it so that is a good sign (I think). Still getting 143-146 at A6, B1, B3 and the LED at A8 still not working.

 

[Paul Birkeland]

Do both halves of the 12AU7 glow?

 

[Flux Capacitor]

just got off work - the 12au7 does glows on both sides I believe. Will add some photos of the soldering and the glowing.

http://i.imgur.com/wWks7DB.jpg[/img

[img]http://i.imgur.com/udie2Qk.jpg

 

[Paul Birkeland]

The photo you posted shows both halves of the 6080 glowing.  If both halves of the 12AU7 glow, then very carefully measure the DC voltage at A8 and A7.

 

[Flux Capacitor]

my mistake, the other tube is glowing on top and bottom from both sides from the looks of it.

A7: 0V
A8: 11.1V

 

[Paul Birkeland]

Connect A3 and A8 with a short piece of wire, then you should be good to go.

 

[Flux Capacitor]

The wire from A8 to A3 fixed the problem! All voltage values within range and the final check the Tip voltage only goes up to ~5V and then back down close to 0V.

Should I keep the standard config for a bit before adding the speedball upgrade? Thanks

 

[Deluk]

Connect A3 and A8 with a short piece of wire, then you should be good to go.

This an extra, non-standard wire, how does it "fix" the problem. Is the non lit led now lit? Does this wire effectively bypass the "failed led and if so wouldn't replacing the led also fix the problem? Replacement is a more elegant fix and the leds are cheap enough.

 

[Paul Birkeland]

This an extra, non-standard wire, how does it "fix" the problem. Is the non lit led now lit?

No.

Does this wire effectively bypass the "failed" led

Yes.

and if so wouldn't replacing the led also fix the problem?

Yes, but you'll need to buy another LED, wait for the LED, then determine at that juncture if your problem is fixed.