Trainwreck Liverpool Voltages

[dab]

Where can I find the correct voltages for the trainwreck liverpool? I tried a search but couldn't locate them. I looked in the trainwreck files and didn't see them there either.

thanks...Dave

[gearhead]

Try:

https://tubeamparchive.com/viewtopic.ph ... ol+voltage

You need to put an "and" between search words. Had me stumped for a while myself.

[dab]

Thanks!

Confirmed my suspicion that I have problems. Below are my voltages. Any help would be greatly appreciated guys.

AC voltage on the PT secondaries is 235VAC each.

At the junction of the diodes the voltage is only 214VDC. B3, 4 and 5 are all in the 140VDC range.

I took all of the diodes out and tested them on my Fluke and they all tested good. Put them back in. Double checked direction and solder points. Same result.

The other weird thing is my heater voltage is low as well.

V1 V2 V3 V4 V5 V6 V7
Pin 1 120 139 135 - - - -
Pin 2 0 0 15 0 0 0 0
Pin 3 0.6 1.1 23 4 4 4 4
Pin 4 1.8 1.7 1.8 1.8 1.8 1.8 1.8
Pin 5 1.8 1.7 1.8 1.8 1.8 1.8 1.8
Pin 6 125 - 130 - - - -
Pin 7 0 - 14 1.2 1.2 190 191
Pin 8 0.4 - 23 - - - -
Pin 9 1.8 1.8 1.8 180 183 181 181

[tele_player]

I'd pull all the tubes (it uses diodes for the rectifier, right?), and figure out what's wrong with the power supply first. None of the other voltages matter if that's not right.

[LeftyStrat]

Something is sucking some serious current. I would make sure I don't have any solder bridges between pins. Might be good to pull all the tubes and take readings. With all the tubes pulled voltages will be a little on the high side. Heaters should be normal.

You can also disconnect the wire running from the diodes to the caps. You should see normal voltage at the ends of the diodes. Then reconnect the diodes to the caps and disconnect the caps from the rest of the amp. This will tell you is you maybe have a bad cap.

Make sure the bleeder resistors are the correct values.

You can sort of work from the PS out by then inserting only power tubes and measuring voltages, then insert the PI tube, measure, then V3, etc.

This will help you isolate where the problem is.

[dab]

Thanks for the great feedback. I will try these ideas out.

Dave

[dab]

I had a bad diode. Don't know why it tested good on the DMM. Now all is well with the PT. Heater and B+ Voltages look good. Getting ready to put in some tubes and continue testing.

Dave

[gearhead]

I had a bad diode. Don't know why it tested good on the DMM. Now all is well with the PT. Heater and B+ Voltages look good. Getting ready to put in some tubes and continue testing.

Dave

Grack, I haven't run across that yet but is one of my fears. Maybe a test with a 9V and a small load resistor would find it.