Tracing noise problem, TwinRev.

[Sea Chief]

..

Chuck I've tried about 4 different tubes in v1 now. I tapped them wiv me whatnot.. nothing suggests tube.

Socket v1.. well I don't know how you'd tell. Ive cleaned the bjesus out of it, brushed clean the top area.

thx SC

[Chuck H]

Did we ever get voltage readings for that tube?

This will tell us if the tube has correct operating conditions in the CIRCUIT. I'm not questioning the tube at this time.

Did you try gently rocking the tube in the socket with the amp on?

This will tell us if there could still be intermittent contact between the tube and socket. You cannot take for granted that cleaning and re tensioning eliminates the socket.

...what happens if you smack the amp while it's on? With V1 in place...

Tapping and prodding is great, but not the same as giving the amp chassis a whack. This could detect an intermittent short or fault that may have been overlooked or we haven examined yet. Slap it like da ho is holding out on ya'.

[Sea Chief]

..

Chuck, just did a few v1 pin readings.

1. 264v
2.
3. 2.2v

4/5

6. I measured on the board after the wire from pin 6: MASSIVE POP just touching here. Touched it again MASSIVE POP.

I didn't get a reading as it scared the fk out of me, both times a momentary touch with probe was all I could do/ unable to keep probe on long enough to get a reading, impossible ( unless I unplug the spkr I'd assume ).

I aint doing this again anytime soon. JesusH.

[Chuck H]

A small or even moderate pop can be normal. I wouldn't expect a loud one. And, once you've already got the probe on there, why not get the reading? It should only pop when you first touch it. Anyway...

How about pin 8? (shouldn't be a loud pop)

Did you rock the tube?

Did you slap the bitch?

[Sea Chief]

A small or even moderate pop can be normal. I wouldn't expect a loud one. And, once you've already got the probe on there, why not get the reading? It should only pop when you first touch it. Anyway...

How about pin 8? (shouldn't be a loud pop)

Did you rock the tube?

Did you slap the bitch?

Chuck. I had my ear goggles on & put the probe on.. other one on chassis/ ground. If it scared me so much wiv me cans on, there aint no way on gods earth I can do this again, let alone keep it on & take a reading. Simply not possible.

I couldn't continue with 7, 8. I was shaking. I not going in there again tonight.

No, the bitch slapped ME!

[Chuck H]

Chuck. I had my ear goggles on & put the probe on.. other one on chassis/ ground. If it scared me so much wiv me cans on, there aint no way on gods earth I can do this again, let alone keep it on & take a reading. Simply not possible.

I couldn't continue with 7, 8. I was shaking. I not going in there again tonight.

No, the bitch slapped ME!

Pull V6. That will shut the amp up while you take voltage readings. But you will need V6 in place for the rocking and smacking. And you may hear a pop with either or both of those tests. We can't trace the loud noises without inducing them.

[Sea Chief]

Pull V6. That will shut the amp up while you take voltage readings. But you will need V6 in place for the rocking and smacking. And you may hear a pop with either or both of those tests. We can't trace the loud noises without inducing them.

True true/ understood. Oh boy.. rocking & smacking wasn't on sunday's 'things to do' list. SC

[Sea Chief]

Pull V6. That will shut the amp up while you take voltage readings. But you will need V6 in place for the rocking and smacking. And you may hear a pop with either or both of those tests. We can't trace the loud noises without inducing them.

Good ok done. Pin 6 = 16v. Pin 8 = 1.8v

But I need to order some diazepam before I smack my bitch up.

SC

[Sea Chief]

Chuck H Rocked, wiggled, then tapped hard. Nothing.

It is seemingly behaving better each time I turn on, ie the odd pop has lessened to 1 in 20 mins. But frustrating not to trace the vol drop ch1 thing.

Thx SC

[pdf64]

…Pin 6 = 16v…

That’s not good, may be a typo or measurement error.

[Sea Chief]

That’s not good, may be a typo or measurement error.

With v6 pulled though? What ballpark should it be pdf?

[Sea Chief]

That’s not good, may be a typo or measurement error.

Hi Pete, just redone test. Both v1 & v2 pins 6: I can indeed confirm very low v1 pin 6 reading..

v1 pin 6 = 8 vdc

(v2 pin 6 = 254 vdc).

SC

[Sea Chief]

With a different tube in v1..

pin 6 = 5.9 vdc

[pdf64]

Maybe the anode load resistor that feeds it is bad? Should be 100k, what does it measure?

[Sea Chief]

Maybe the anode load resistor that feeds it is bad? Should be 100k, what does it measure?

Hi Pdf, well now the 100k joining from pin 6, is reading open circuit. The identical twin 100k next to it reading 140k.

The identical pair of 100k resistors on V2, are both reading 100k.