Hi.

While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel? Mine is doing it
intermittently and sometimes loudly, out of the left channel.
Is it likely to be a resistor burning up, or something about
the valves? Is it likely to be in the output stage valves or
cathode resistors, or...? It's starting to drive me nuts!

Is this the kind of symptom that tends to always have the same
cause?

Thanks for any pointers.


Martin

"Fleetie" wrote in message
...
Hi.

While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel? Mine is doing it
intermittently and sometimes loudly, out of the left channel.
Is it likely to be a resistor burning up, or something about
the valves? Is it likely to be in the output stage valves or
cathode resistors, or...? It's starting to drive me nuts!

Is this the kind of symptom that tends to always have the same
cause?


Hello Martin.

The first thing I would suspect is the contact between the
socket pin grips and the valve pins on the input and driver
tubes, particularly if they are B9A type (miniature nine-pin)
Some (particuarly Chinese) valve bases have contacts that
open up, and don't contract again to grip the pin firmly.

If this is the cause, you can find the culprit by a little
"waggling" (these hi-tech solutions are often the best!)

Then, switch the amp off, pull out the valve, and clean the pins
with aerosol contact cleaner. Spray a little into the valve
base also.

Hope this helps.
Iain

"Iain Churches" wrote in message
i...


"Fleetie" wrote in message
...
Hi.

While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel? Mine is doing it
intermittently and sometimes loudly, out of the left channel.
Is it likely to be a resistor burning up, or something about
the valves? Is it likely to be in the output stage valves or
cathode resistors, or...? It's starting to drive me nuts!

Is this the kind of symptom that tends to always have the same
cause?


Hello Martin.

The first thing I would suspect is the contact between the
socket pin grips and the valve pins on the input and driver
tubes, particularly if they are B9A type (miniature nine-pin)
Some (particuarly Chinese) valve bases have contacts that
open up, and don't contract again to grip the pin firmly.

If this is the cause, you can find the culprit by a little
"waggling" (these hi-tech solutions are often the best!)

Then, switch the amp off, pull out the valve, and clean the pins
with aerosol contact cleaner. Spray a little into the valve
base also.

Hope this helps.
Iain

As well as the above, have a look at the valves themselves when on. I had a
valve once that did what you've reported, and it was caused by the vacuum
having gone "bad". It was visible as a much greater than usual blue glow.
All valves will glow blue slightly, especially the larger power valves and
rectifiers, but if one is glowing more than the others, that might be the
culprit.

S.
--
http://audiopages.googlepages.com

"Serge Auckland" wrote in message
...

"Iain Churches" wrote in message
i...


"Fleetie" wrote in message
...
Hi.

While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel? Mine is doing it
intermittently and sometimes loudly, out of the left channel.
Is it likely to be a resistor burning up, or something about
the valves? Is it likely to be in the output stage valves or
cathode resistors, or...? It's starting to drive me nuts!

Is this the kind of symptom that tends to always have the same
cause?


Hello Martin.

The first thing I would suspect is the contact between the
socket pin grips and the valve pins on the input and driver
tubes, particularly if they are B9A type (miniature nine-pin)
Some (particuarly Chinese) valve bases have contacts that
open up, and don't contract again to grip the pin firmly.

If this is the cause, you can find the culprit by a little
"waggling" (these hi-tech solutions are often the best!)

Then, switch the amp off, pull out the valve, and clean the pins
with aerosol contact cleaner. Spray a little into the valve
base also.

As well as the above, have a look at the valves themselves when on. I had
a valve once that did what you've reported, and it was caused by the
vacuum having gone "bad". It was visible as a much greater than usual blue
glow. All valves will glow blue slightly, especially the larger power
valves and rectifiers, but if one is glowing more than the others, that
might be the culprit.

Yes. Often when swopping valves from left channel to
right channel to find the culprit, you may find the problem
disappears, as the action of fitting and removing cleans the
pins a little. I recently had a preamp on my bench with an
ECC82 which was silent in the left channel, but rustled when
on the right.

Iain

Thanks, guys.

I'm gonna do a valve swap on the output valves now,
and see what happens.

I'll try a bit of "valve wiggling", too.


Martin

Fleetie wrote:

Thanks, guys.

I'm gonna do a valve swap on the output valves now,
and see what happens.

I'll try a bit of "valve wiggling", too.

My guess would be that it's from an internal insulation
breakdown, or a failing cap...coupling or cathode bypass.

Ian

"Fleetie"

"Fleetie the Scumbag, OVERSNIPPING Autistic ****wit"

** Where is the rest of my post ???

YOU ****ING **** !!!


Almost any modern * moving coil * cartridge operates to over 40 kHz.

What an ignorant **** you are.

** And I said I was surprised that OLD cartridges worked to
those frequencies.


** Modern in this case = post the 1950s, ie - most stereo MC cartridges.

YOU ****ING **** !!!


Are you going to call me an autistic ****wit, now, Phil?


** The cap fits you like a glove - so you have to wear it.

YOU ****ING **** !!!


Phil, you do seem to use that insult a lot.


** Can't be avoided when publicly outing scum of the planet - like you.

YOU ****ING **** !!!



....... Phil

"Fleetie the Criminal **** "


While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel?


** There is no usual cause - you ****ing **** .

There are lost of different causes.


Is this the kind of symptom that tends to always have the same
cause?

** Darn few of them exist - you ****ing **** .

I suggest you stick your slimy tongue of the HT line and see if you can
taste the problem.




...... Phil

Fleetie wrote:
Hi.

While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel? Mine is doing it
intermittently and sometimes loudly, out of the left channel.
Is it likely to be a resistor burning up, or something about
the valves? Is it likely to be in the output stage valves or
cathode resistors, or...? It's starting to drive me nuts!

Is this the kind of symptom that tends to always have the same
cause?

Thanks for any pointers.


Martin


In my limited experience (er, once), it was down to a faulty valve. One
of the big ones.

Rob

"Rob" wrote in message
...
Fleetie wrote:
Hi.

While I'm here, does anyone know the usual cause for a valve amp
constantly "rustling" out of one channel? Mine is doing it
intermittently and sometimes loudly, out of the left channel.
Is it likely to be a resistor burning up, or something about
the valves? Is it likely to be in the output stage valves or
cathode resistors, or...? It's starting to drive me nuts!

Is this the kind of symptom that tends to always have the same
cause?

Thanks for any pointers.
In my limited experience (er, once), it was down to a faulty valve. One of
the big ones.

It can be all manner of things, so you need to make a list and start at
the beginning. It might be a dry joint somewhere. Whatever it is, it
can be found with systematical searching. The hi-tech methods of
a) wiggling and b) tapping usually provide the answer.

Cheers
Iain