Volume drop problem

[goingelectric]

Sorry, but I'm somewhat new here. I haven't been posting very much here and I couldn't find some exact answers using the search function. (I did find something that might be the answer to my problem)

Whatever channel I'm playing on, the volume kinda drops out and comes back in.
The post I found suggested the poster might have a blown power tube.

However, my tube is "glowing" and I'm thinking it can't be a blown tube.

the volume just fluxes, it's not brutal, and it's not that constant but it happens every so often when I play the amp.

Maybe once or twice every 5-10 minutes? And it's worse (I THINK) when the amp hasn't warmed up quite.
Although the problem still persists when the amp has warmed up, just not as often.

Teddy

 

[Rob Tahan]

Tubes can definitely be glowing and be bad. 100% sure of that.
Ive had that exact problem with my herbert when i first got it.
USUALLY its just a tube or two. Powertubes.
Change them and if not...

 

[MOOSEHEADS]

Be sure to use a good line conditioner to power your amp. Voltage spikes and drops will do the same thing.

 

[herbertmark5]

i would still think its a powertube. the tubes do blow and still glow. ive watched it happen and get your symptoms.the tube looked like the sun then later looked kinda normal

 

[goingelectric]

any recommendations for a power conditioner?
are the ENGL tubes what are stock?
sorry, got the amp second hand!

 

[MARK2C]

What Diezel is it ?

Diezel preamps have buffers, mixers and the phase inverter in line with the preamp signal. Go to the Diezel website
and in the Tech Corner it lists all the preamp tube functions in order. Pay close attention to the spots
that say "used by all channels". If you have a flaky pre in one of these positions it can kill the signal
to the power amp.

For power tubes, first check your bias. If they are too hot you could be sending them into cutoff. It is possible
that a super high bias may cause your tubes to basically shut off when a normal signal is applied. Just imagine driving
your car at full throttle and then it goes 20% more. If your bias is too high or has been run too high for a while there is
a good chance the tubes are worn out and need to be replaced.

 

[goingelectric]

What Diezel is it ?

Diezel preamps have buffers, mixers and the phase inverter in line with the preamp signal. Go to the Diezel website
and in the Tech Corner it lists all the preamp tube functions in order. Pay close attention to the spots
that say "used by all channels". If you have a flaky pre in one of these positions it can kill the signal
to the power amp.

For power tubes, first check your bias. If they are too hot you could be sending them into cutoff. It is possible
that a super high bias may cause your tubes to basically shut off when a normal signal is applied. Just imagine driving
your car at full throttle and then it goes 20% more. If your bias is too high or has been run too high for a while there is
a good chance the tubes are worn out and need to be replaced.

I don't know how to hold a soldering iron, nor do I know how to operate a measuring device.
I think both me and the amp would be in danger if I started sticking my sticky fingers in there.

Is there an easier way to check this than Bias?

Maybe I should just send it to a tech?
Anyone know a tech in norway?

 

[MARK2C]

What Diezel is it ?

Diezel preamps have buffers, mixers and the phase inverter in line with the preamp signal. Go to the Diezel website
and in the Tech Corner it lists all the preamp tube functions in order. Pay close attention to the spots
that say "used by all channels". If you have a flaky pre in one of these positions it can kill the signal
to the power amp.

For power tubes, first check your bias. If they are too hot you could be sending them into cutoff. It is possible
that a super high bias may cause your tubes to basically shut off when a normal signal is applied. Just imagine driving
your car at full throttle and then it goes 20% more. If your bias is too high or has been run too high for a while there is
a good chance the tubes are worn out and need to be replaced.

I don't know how to hold a soldering iron, nor do I know how to operate a measuring device.
I think both me and the amp would be in danger if I started sticking my sticky fingers in there.

Is there an easier way to check this than Bias?

Maybe I should just send it to a tech?
Anyone know a tech in norway?

Can you change a preamp tube ? It's better than doing nothing.

 

[goingelectric]

What Diezel is it ?

Diezel preamps have buffers, mixers and the phase inverter in line with the preamp signal. Go to the Diezel website
and in the Tech Corner it lists all the preamp tube functions in order. Pay close attention to the spots
that say "used by all channels". If you have a flaky pre in one of these positions it can kill the signal
to the power amp.

For power tubes, first check your bias. If they are too hot you could be sending them into cutoff. It is possible
that a super high bias may cause your tubes to basically shut off when a normal signal is applied. Just imagine driving
your car at full throttle and then it goes 20% more. If your bias is too high or has been run too high for a while there is
a good chance the tubes are worn out and need to be replaced.

I don't know how to hold a soldering iron, nor do I know how to operate a measuring device.
I think both me and the amp would be in danger if I started sticking my sticky fingers in there.

Is there an easier way to check this than Bias?

Maybe I should just send it to a tech?
Anyone know a tech in norway?

Can you change a preamp tube ? It's better than doing nothing.

I can change tubes. but isn't this a powertube thing?
anyways, since the amp got shipped from the US. it's prolly a tube issue.

shipping it to germany might not even help as the shipping will knock out the tubes.

guess I just have to buy new tubes and a meter to check the bias........... :S or find
someone who can bias it for me

 

[reussen]

I had this problem with my Einstein. Problem with mine was a bad pre-amp tube: the one that takes care of the FX send or return (not sure). Amp sounded fine, but volume dropped out and then immediately came back on again. Changed the tube, problem solved.

Hope that helps!

 

[goingelectric]

good site for buying new tubes?

 

[Ventura]

good site for buying new tubes?

Depends where ya live...

V.