Pre amp distortion

[lfranz5451]

one of the channels on my groove tubes supre all of a sudden is engulfed in distortion..and i dont mean good, useable distortion...this is a bad hissing, distortion...the unit is only 60 days old...the other channel is still clear as a bell, pristine and sheen...beautiful..anyone know what might be the cause of this?


lfranz5451

[Matt Syson]

Hi
Could well be a duff valve, they can do this kind of thing.
Valves are like temperamental lightbulbs and should be regarded as such. Find a replacement and swap one at a time. POWER OFF EACH TIME before touching anything.
Call GT and ask for suggestions.
At 60 days I doubt valve failure is warrantied but they should at least make helpful noises toward you.
Matt S

[lfranz5451]

just got it fixed....oddly enough at only 60 days it was a blown tube


lfranz5451

[Matt Syson]

Hi
Not odd at all really. There is a known and often quantified 'law' about failures. High in the first few months then low for probably years then gradually increasing as it gets really old.

Known as a 'bathtub curve' when shown on a chart.
Matt S

[Bassmec]

Originally Posted by Matt Syson

Hi
Could well be a duff valve, they can do this kind of thing.
Valves are like temperamental lightbulbs and should be regarded as such. Find a replacement and swap one at a time. POWER OFF EACH TIME before touching anything.
Call GT and ask for suggestions.
At 60 days I doubt valve failure is warrantied but they should at least make helpful noises toward you.
Matt S

When you buy modern equipment you occasionally find that you have also bought an
all new chinese invention, this is called the partial vaccume electron tube.
Buy NOS tubes by the most sought after names and none of those have GT written on them.
I have used RCA JAN 1620 tubes that still test and sound great and the date code is 1938! Pretty good for a light bulb isn't it.