RCA 6L6 tubes are toast?

coyotemorgan · March 1st, 2005, 09:17 AM

I've seen some RCA 6L6GC Black Plates for sale that have circular burn(?) marks on the glass, and one of which has some white flakes in the tube. Are these tubes toast or worth trying at a reasonable price?

DADGAD · March 1st, 2005, 10:37 AM

The sure way to know is to test them on a tube tester and listen to them in an amp. White flakes may only be mica from the insulators and the deposits on the glass may be manufacturing coatings. Can you post a picture?

Check your PM inbox.

Gary

coyotemorgan · March 1st, 2005, 03:33 PM

Here's what they look like:
http://imagehost.vendio.com/bin/view...ary, check PM.

mmahoney · March 1st, 2005, 04:52 PM

I've used older NOS tubes with that type of circular black pattern ... the one pictured on the right with the bubbly brown stuff looks a little funky though.

but a tube tester should tell all.

cheers,
Mike

1612112 · March 1st, 2005, 05:21 PM

Quote:

Originally Posted by coyotemorgan

I've seen some RCA 6L6GC Black Plates for sale that have circular burn(?) marks on the glass, and one of which has some white flakes in the tube. Are these tubes toast or worth trying at a reasonable price?

That silvering is caller the "Getter Flash" The Getter is a component in the tube which through a process of firing absorbs contaminants left from having a soft vacuum during manufacture. As it is fired the silver flash is generated and is a sign that contaminates were burned off.

The fact that one is a bit chard looking could mean that there is a tiny vacuum leak around the electrical connections. which has introduced oxygen into the envelope. The white stuff (which I do not see in the photo) is also evidence that contaminates have been burned off probably over time. I personally would not bother buying this tube.

pjb

coyotemorgan · March 1st, 2005, 05:25 PM

Thanks for the advice, guys. I was thinking that at a cheap price these might be ok, but then why settle for the bad or excessively worn for any price.

1612112 · March 1st, 2005, 05:35 PM

Quote:

Originally Posted by coyotemorgan

Thanks for the advice, guys. I was thinking that at a cheap price these might be ok, but then why settle for the bad or excessively worn for any price.

Don't let me discourage you, they might sound great for a day or so, and in the studio wouldn't be a problem if they burned up.
pjb

March 1st, 2005, 09:17 AM	#1 (permalink)
coyotemorgan Tele-Meister Join Date: May 2003 Location: Toronto Posts: 147	RCA 6L6 tubes are toast? I've seen some RCA 6L6GC Black Plates for sale that have circular burn(?) marks on the glass, and one of which has some white flakes in the tube. Are these tubes toast or worth trying at a reasonable price?

March 1st, 2005, 10:37 AM	#2 (permalink)
DADGAD Tele-Holic Join Date: Mar 2003 Location: Palmdale, CA Posts: 764	The sure way to know is to test them on a tube tester and listen to them in an amp. White flakes may only be mica from the insulators and the deposits on the glass may be manufacturing coatings. Can you post a picture? Check your PM inbox. Gary __________________ "I need to learn some new scales and stop obsessing about this stuff." http://www.myspace.com/slickshoes

March 1st, 2005, 04:52 PM	#4 (permalink)
mmahoney Tele-Meister Join Date: Nov 2004 Posts: 146	the silver / black is OK I've used older NOS tubes with that type of circular black pattern ... the one pictured on the right with the bubbly brown stuff looks a little funky though. but a tube tester should tell all. cheers, Mike

March 1st, 2005, 03:33 PM	#3 (permalink)
coyotemorgan Tele-Meister Join Date: May 2003 Location: Toronto Posts: 147	Here's what they look like: http://imagehost.vendio.com/bin/view...ary, check PM.

March 1st, 2005, 05:25 PM	#6 (permalink)
coyotemorgan Tele-Meister Join Date: May 2003 Location: Toronto Posts: 147	Thanks for the advice, guys. I was thinking that at a cheap price these might be ok, but then why settle for the bad or excessively worn for any price.