Billy Murdoch
From:
Glasgow, Scotland, U.K.
|
Posted 29 Apr 2007 9:20 am |
|
Hi Brad,
I have a SGBB which is now three years old and it is one of my most valuable possessions.
My question is on the tube,
I am ignorant of electronics.
During the life of the tube does it deteriorate?
I have not noticed any deterioration in sound and was wondering if it has been changing subtly over the months.
Is there a time for changing or do I wait till the tube gives obvious sounds of needing a change?
I guess my unit has about 1250 hours of use.
Best regards
Billy |
|
Brad Sarno
From:
St. Louis, MO USA
|
Posted 1 May 2007 4:41 am
|
|
Billy,
The tubes made these days are not all that consistent. Also, more frequent power on/offs can also reduce tube life. I've seen preamp tubes last as short as a couple of years and as long as 20+ years. Preamp tubes typically degrade slowly. Some get noiser and hissier. Others just start to get dull and dark. So when you notice the tube starting to sound worse than before, then it's probably time. For a while I was installing JJ tubes, but about a year ago I got a bad batch of those and I lost a little bit of faith in JJ, so I've been using EH brand, they're sort of the premium Sovtek's, and they've been treating me very well so far.
So I'd say just keep listening and if someday it seems that the sound just isn't what it was, then it's probably time to drop about $12 to $15 and get a fresh tube.
For fun, you can try a variety of NOS tubes (new old stock). General Electrics sound good, Sylvanias sound good, RCA's are a bit hard and bright in the Black Box. Then of course you can buck up even more and try a Telefunken or Mullard or other premium ones.
Just make sure you try a 12AU7, ECC82, or other versions of that tube.
Take Care,
Brad |
|
