VH4 Biasing question

[Crash]

I'm tying to bias my VH4 by the Output Transformer method. I followed the instructions
but I am not getting anything from the Yellow wire. Below is what I'm getting off the OT.
Is this normal?

Thanks

Blue -71.9
next 0
Black
Next -62.5
yelllow 0

 

[duesentrieb]

You just have to read the two sides:

red vs. yellow
red vs. blue

You are measuring both sides of the OT vs. its middle (red).

ok?

 

[Crash]

Thanks for the reply.

Yes, I'm doing Black lead(Meter) on the center tap Red and the Red lead(meter) or the Blue and then I'm checking that against the Yellow. I'm not getting anything on the Yellow but I get it off the terminal between the Red and Yellow. Is there a way for me to check if the tranny is correctly wired?

 

[duesentrieb]

My guess is that there's a fuse between the the OT and the tubes (I don't have a VH4 here). Lets wait for Peter.

Just an idea: swap those tubes on the "yellow OT side" to the blue and vice versa - result?

 

[Peter Diezel]

Check the tube fault fuses and try it again.

 

[Crash]

Peter, Thanks for the quick reply!

Just checked the fuses and 3 & 4 were dead. Shoudn't the red lead been on showing this?
I purchased the head used on ebay and it has never sounded right when I start to crank it.
Could this be why? Tomorrow I will try and bias it again... Then see how she sounds.

 

[Crash]

Does anyone know what value the resistor is on the Led tube faults and which pin it connects to? I have one missing on 3

 

[mdc]

i have the same problem but a bit worse... i don't get anything (00.0 on the blue and 00.0 on the red wire).
does anyone know whats the problem?

 

[duesentrieb]

i have the same problem but a bit worse... i don't get anything (00.0 on the blue and 00.0 on the red wire).
does anyone know whats the problem?

The amp is dead?

 

[mdc]

i have the same problem but a bit worse... i don't get anything (00.0 on the blue and 00.0 on the red wire).
does anyone know whats the problem?

The amp is dead?

nope, the amp works exactly as he should.

 

[duesentrieb]

(thats what I was expecting)

You have to set your DMM to read Amperes (not Volts). 200mA A DC !

With most DMMs you need to use a different socket for reading currents !!!

 

[mdc]

(thats what I was expecting)

You have to set your DMM to read Amperes (not Volts). 200mA A DC !

With most DMMs you need to use a different socket for reading currents !!!

i use this one at have set it to 200mA:

 

[duesentrieb]

Check the fuse inside the DMM.

 

[mdc]

Check the fuse inside the DMM.

i've checked it and it seemed to be blown. i already replaced it and will try to bias the amp again this evening. what appears strange to me is that i also tried an other DMM, which worked neither... but who knows, maybe it will do his job with the new fuse.

 

[duesentrieb]

Its easy: if you have a working amp, there are indeed some electrons flying inside the OT, which should be measurable

 

[mdc]

Its easy: if you have a working amp, there are indeed some electrons flying inside the OT, which should be measurable

in der tat
ich gehe jetzt gleich ins lokal und versuchs noch mal. gebe dann bescheid. danke schon mal!

 

[mdc]

habs jetzt nochmals versucht. das ergebnis ist äusserst merkwürdig. zuerst hats mir bei beiden OTs (hab nen VH4S) nur was angezeigt, wenn ich das rote kabel des DMM am blauen kabel angeschlossen habe. anschliessend hats mir beim einen OT bei angeschlossenem blauen kabel nichts mehr angezeigt, dafür aber, wenn ich anstatt des blauen das rote kabel getestet habe. wahrscheinlich ist mein DMM etwas heimtückisch und launisch... na ja, schlussendlich konnte ich jedenfalls alle testen ausser die kombination OT1 (mittleres kabel rotes kabel). sollte aber gut sein so.

danke für die hilfe