Hi to all I'm new here and according to what I read in the international forum, this is probably the best place to ask those question, so I give a try  :laugh:

Well, I'm a happy owner of a screamer head and yesterday I noticed that one of the two output tubes was not glowing like the other one. It was in away much dimmer, probably it was not glowing at all.

Soundwise the amp sounded very well nonetheless, maybe just a lack of volume. Should i replace the tubes? If so, I am new to tubes as the screamer is my first all-tube amp and no matter how i search the web I'm still confused on a couple of things.

First of all: I'm going not going to change type of tubes (that means i'm going to put other 6l6GC's in it) Do i HAVE to rebias? What if I change brand of tubes, but not type of tubes?

Second: if I have to bias the amp, is there a good guide for the screamer in order to help me a bit?

Thanks in advance for your kind answers. 

Hi !

What is not glowing ? The only thing that should glow is the heater. So heaters do glow brighter than others - that is normal BUT if the heater i snot glowing at all I can be sure that the tube is not working. This might be because of a broken heater or missing filament voltage. In this case you must of course replace the tubes - welll, better all the power tubes.
If you replace the power tubes it is always a good idea to check and adjust bias. Please see:
http://www.tube-town.net/diy/bias-setup-e.pdf

Best regards, Dirk

Hi,
crazy, last weekend I noticed exactly the same probs with my screamer: one 5881 doesn´t glow and stays cold. When I change the position of the poweramp tubes, the same valve doesn´t work as well, which obviously means that one tube and not the amp is damaged. The Amp runs in both positions...
Regards, Frank

Zitat von: shred252 am Nov 19, 2007, 07:41
Hi to all I'm new here and according to what I read in the international forum, this is probably the best place to ask those question, so I give a try  :laugh:

Well, I'm a happy owner of a screamer head and yesterday I noticed that one of the two output tubes was not glowing like the other one. It was in away much dimmer, probably it was not glowing at all.

Soundwise the amp sounded very well nonetheless, maybe just a lack of volume. Should i replace the tubes? If so, I am new to tubes as the screamer is my first all-tube amp and no matter how i search the web I'm still confused on a couple of things.

First of all: I'm going not going to change type of tubes (that means i'm going to put other 6l6GC's in it) Do i HAVE to rebias? What if I change brand of tubes, but not type of tubes?

Second: if I have to bias the amp, is there a good guide for the screamer in order to help me a bit?

Thanks in advance for your kind answers.