Tubes Asylum

Posted by Morse (A) on September 25, 2002 at 20:33:03

In Reply to: Tube Breakin? posted by Lynn Epstein on September 25, 2002 at 09:14:05:

Hi Lynn.

Tubes will indeed change their sound over time. Try a "fresh out of the box" JAN Philips 12AX7WA and compare it to one with a couple of hundred hours on it.

By the way, in tube radio circuits it's common to have to tweak the things after the first 100 hours or so of use, because of the tube's subtly altering electrical properties. This was imparted to me by an EE at work when I asked for practical tips on building the superheterodyne radio receiver that I've got in the design stage over here. He's an old tube guy from the 'good old days', not a "crazed audiophile".

So, yes Virginia, your tubes really will sound different after the first hundred hours or so. For which all those of us who have heard a 'fresh out of the box' JAN Philips 12AX7WA are VERY thankful.

Regards,
Morse