Trace Elliot Velocette Heaters

[bbirling]

I have a Trace Elliot Velocette on the bench for repair. Strange issue on the heaters. None of the filaments light.
If I test voltage at pins 4/5 on the output tubes, I get 3/4 volts individually when connected to ground. If I test pin 4 to pin 5 I get nothing. There is continuity betwen the pins. If I test the heater connection at the connector to the pc board I get 7 volts across the wires and 3/4 individuall to ground. Any thoughts. The pdf with the schematic is to large to post. I will have to see if I can reduce the size.

Bruce

[sluckey]

You have an open circuit between the connector and the tubes. Maybe a crack in the filament trace. If a visual inspection doesn't reveal the open circuit, use your ohm meter.

[bbirling]

Thats the thing. I get continuity between any heater pin and the connector at the board. (where the pt heater wires connect) So there appears to be a complete circuit all the way through.

Bruce

[birt]

you did measure the heaters at 12--7 tubes between pin 4 and pin 5? they are normally connected. you should measure from pin 4 (and 5) to pin 9.

[sluckey]

Thats the thing. I get continuity between any heater pin and the connector at the board. (where the pt heater wires connect) So there appears to be a complete circuit all the way through.

Pull all tubes so you won't be reading thru the tube filaments. And disconnect the connector so you won't be reading thru the PT filament winding. Now use your ohm meter.

[bbirling]

Working at disconnecting the plug now. Correct on the measuring voltage on 12--7's.
The heaters all have connectors on the pcb at the tube sockets.

There would appear to be an issue at V4. Hard to isolate it to the board or maybe a bad connection in the connector. I can move the wires and get a connection. It's only on the pin4 side of the heaters. After V3 everything checks out fine. With all the silicone an connectors this is a real pain in the crack to work on.

Bruce

[bbirling]

OK, Got the heaters figured out. There was a bad connection internall in the connector on the PC board. So far it sounds very over driven and not very loud. Time to take voltage readings and see what is up.

Bruce

[bbirling]

I contacted the Manuf and hopefully can get a clean schematic that's legible. In the mean time I too the voltages.

Seem pretty close to me for a 2 EL84 amp but a good schematic will help

EL84   1    2    3    4    5    6    7    8    9
         0    0    12  h    h    0    360  0    360
         0    0    12  h    h    0    360  0    360
12ax7 272 45  64   h   h    266  45   66  h
         153  0   1   h    h    214   0   2    h

[bbirling]

Has anyone had any experience with one of these. I have the schematic but the PDF is to large to upload. I have the heater situation figured out but, the volume is low and has ugly distortion. I have been through it and all the resistor tested out good. I posted the voltages earlier. Any help would be appreciated.

Bruce