Hi Bob..
Thanks for your reply!
The procedure you mentioned is very helpful!
I'll do just that.
Very interesting history re: mkIII, etc.
I love knowing those little tidbits!
You will have to go back and forth
between the two channels because adjusting
the left channel has a slight effect on the
right channel.
Oh how I remember that from the days of using
a couple of stock 70s.
Back when they were already seriously deteriorating,
before eventually retiring them
to sit around waiting for the rebuild I'm just finishing.
With sooo much going wrong with them, the back
and forth process took a looooong time...
Bias supply going... tube sockets in such poor
shape you couldn't tell whether it WAS the bias supply..
Can cap iffy at best..
And that very pretty sparkling in the rectifyer........
<sigh> such nostalgia..........
If you rotate those controls fully counterclockwise
you will be at the lowest setting when you
power up. The bias will be low -
Ok... let me try to get this straight here..
Usually I can dope these things out fairly easily,
but I got so much going on right now, that brain
fog rules the day...
"lowest setting" = less negative bias against the
tubes "running away", right?
Wouldn't you then be better off with them fully clockwise
then?
------------------
I've another question for you, if you'd be so kind..
The tubes I'm using are the JJ *E-34-L* not
EL34.
I mention this, both as part of my initial question,
and also in regard to your biasing recommendations.
When reading what others said about them around
the net, I noticed that many
(at least by those who mess with this sort of thing)
felt that they sound best biased "hotter" than
normal for EL34s.
Most suggest 1.65 or even 1.7v.
They say these tubes just don't sound great at
1.56v.
Dull, cold, are the terms used....
This copied from the tubedepot details page
for the JJ E34L:
"With a slightly higher grid voltage than other EL34
(-13.5 to -16.5 vs -10 to -13.5 volts for the EL34)
this tube offers tight low end with smooth mids."
(The last line is of course, irrelevant.)
Perhaps they mean higher grid voltage spec, or
draw, requirement? capability?
I'm a bit lost...
I assume its draw... hence more bias?
I want nice long tube life like the next guy, but
I'm not sure whats best for the E34Ls, including
the sound quality consideration.
Maybe I should start out at the "official" 1.56v spec?
Btw, triode has 15ohm resistors too for $1.15.
(which I used, btw)
Here:
http://store.triodestore.com/15ohm2wcf.html
They're big.. a pretty red... look like nice quality,
and are made in Spain :-)
Thanks so much for your help...
Can't wait to get 'er running!
Greg