[Jukebox-list] Moron vacuum tube question.

[Don]

Hi Kyle,

Hum....
So.... how do you know the 6L6 is "dead"..... no filament glow?? (assuming 
its glass envelope)

Without the schematic I will assume the two 6L6s are connected in a push 
pull circuit. If one of the two 6L6's is really dead the other should be 
able to drive one side of the primary and you will get "some" sound.  Again, 
without the schematic I risk a skate on thin ice here so maybe the folks 
with a schematic for your unit will correct me.   However, invariably when 
we see two 6L6's they are both "driving" or energizing the output 
transformer's primary winding and that winding, in such a situation is 
usually center-tapped with the center-tap connected to the B-plus high 
voltage supply.

Given the truth of all this in your situation.... then.... if you have one 
dead 6L6..... what you might consider is installing two "new" 6L6 tubes of 
equal or almost equal strength. These would be called a "matched pair" and I 
think Antique Electronics will sell you matched 6L6's..... for a 'bit' more 
dough.   Theoretically these "same strength" tubes will drive the o/p xfmr 
primary symetrically, ergo you'll get the least distorted sound.

On the other hand if you test the remaining good 6L6 and it washes up just 
fine as a good strong tube, then try to find a match for it.....  ie. a 6L6 
that gives similar test results on the SAME tube tester.  I  do this easily 
since I have a really good tube tester.

Anyway, I hope this helps.
Don


----- Original Message ----- 
From: "Jackie" <etreble7 at verizon.net>
To: "Jukebox mailing list" <jukebox-list at lists.netlojix.com>
Sent: Wednesday, April 11, 2007 5:22 PM
Subject: Re: [Jukebox-list] Moron vacuum tube question.


> Kyle,
> just kidding.............DON'T answer that, LOL
> love ya,
> Jackie
>
> ----- Original Message ----- 
> From: "Mechanical Music of S.F." <mechanicalmusic at hotmail.com>
> To: <jukebox-list at lists.netlojix.com>
> Sent: Wednesday, April 11, 2007 8:14 PM
> Subject: [Jukebox-list] Moron vacuum tube question.
>
>
>>
>> OK, in the G120 I just finished up, one of the two 6L6 tubes is dead.
>> Juke still plays loud and (what I think is) pretty clear.
>> What gives?  Are the pair some kind of oscillator or something?
>>
>> Have another one on the way....
>>
>>
>> Kyle ~
>> Mechanical Music of San Francisco
>>
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