Question on tube connections

  • Thread starter Thread starter nate_dennis
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nate_dennis

nate_dennis

Well-known member
So this is actually related to an old Hammond L103 I scored for cheap, but the circuit ideas should be the same as guitar amps . . . .so heres the question....or rather questions.

When I fire her up, not all of the tubes glow. Is it normal for tubes to not glow or does that indicate a problem? If it is a problem (as I suspect it is) how I determine if the problem is a connection or a bad tube? Thank you so much for the help guys. Someday, maybe, I'll be able to help you all out.


-Nate
 
Hey, y'all wanna open a huuuuuuuuuuge can of worms? It's times like these you'd be glad you had a decent tube tester.

can_o_worms.jpg
 
ranjam said:
Hey, y'all wanna open a huuuuuuuuuuge can of worms? It's times like these you'd be glad you had a decent tube tester.

can_o_worms.jpg
Click to expand...

I just got a good used tube tester a month ago on e-bay. It is a 1966 Hickock 6000A. It is a mutual conductance tester. It really helps in diagnosing tube problems. Try cleaning all the tube sockets with deoxit, make sure the power is off but remember filter capacitors can still hold high voltages for a while.
VP:D
 
ranjam said:
It's times like these you'd be glad you had a decent tube tester.
Click to expand...

Sure I would, but this organ is the first thing I have that uses tubes, so until now I haven't needed one.

Thanks Arcaxis, i think I can get my hands on a voltometer. I'll check out that stuff.
 
nate_dennis said:
When I fire her up, not all of the tubes glow.
Click to expand...

I have an L103 in my studio...sweet organ. :cool:

But let me ask a dumb question...
Looking at the tubes for “glow” is one thing...
…but does it play OK or not? :)

If you are not getting any sound or no reverb or just fizzy/faint sound, AND some tubes appear to be dead, or not glowing...then maybe they are bad.
But some tubes may seem like they are not "glowing" until you push them harder (by playing)...and then other tubes barley glow all the time. The only tubes than could really kick out some serious glow are the power tubes, but again, only when you push them harder. At rest...they might just barely emit a light glow.
Though getting back to my question...if the organ plays and sounds good, then I wouldn't worry about the lack of glow

By the way...my L103 still has the original tubes from 1965...and still plays great, but that's not saying tubes don't go bad at some point.

What condition is your L103? Did it come out of a nice environment or was it sitting covered in someone’s basement for 20 years?

Oh...and if it was not regularly played/maintained...check the oil cups before you run it to much. In case you don't already know...they need oil about once a year or so...but you want to check before over filling, otherwise you will just end up with a lot of oil on the base of the cabinet.
Use real Hammond oil...find it on eBay.
 
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