post #46 of 298
9/23/08 at 10:36pm
it should be quite easy to discern if the fault is in the amp or the
sophia... just try another rectifier and see if the spark is constant...
preferably another rectifier with a low reservoir requirement like
the 274b, for example the 5r4gy... my guess is that the sophia
princess does not emit these sparks from the beginning but slowly
goes bad with repeated play... chinese and soviet tubes are ok
sounding tubes but are not known to last... my valveart 274b,
a rebranded shuagang tube, lasted only 4 mos. of light playing...
by light playing i mean approx. 10 hrs. per week... if you notice
your amp is killing off tubes left and right within short periods of
time then you can be certain the amp is at fault...
try using the sovtek 5u4g that came along with the woo amps...
it has a fairly low resevoir requirement of 32 uf...
*btw, getting a tube tester is a good investment if you're planning
on keeping your tube amps in good condition and away from
faulty tubes with shorts or vacuum leaks...
...I will speak to Jack and make sure he is within the 90ma limits in the email response from Sophia and get the Sophia replaced as it is very likely a faulty one. I also wonder if the premium parts upgrade has made a difference to the compatibility with the Sophia 274B tube....
i'm pretty sure jack will tell you it's within the 90ma spec... that doesn't mean
they made a goof during the build of your amp to unknowingly allow more...
if there is more than 90ma being pulled from the rectifier, then the two 6de7
tubes in front should be glowing redder than normal... and possibly cause a
hum in the headphone too...
i would stay away from the sophia tube for awhile and just use the new
rectifier you got... if you encounter more oddities then alert jack asap and
get that amp looked at... good luck.