Bare Knuckle Pickups Forum

At The Back => The Dressing Room => Topic started by: Dmoney on May 15, 2010, 08:56:03 PM

Title: Bad JJ valves
Post by: Dmoney on May 15, 2010, 08:56:03 PM

anyone else had problem?

I got an EL34 quad from a guy in south west london. brand new. dude works as a tech.
1 was arcing internally
had two spares. 1 of those was arcing internally.
got some new 6L6GC's last week
1 of those was arcing internally.

is it just me?
I use that online bias calc (http://www.ax84.com/contrib/biascalc.php) or the weber one and bias my valves using a bias rite to the colder side of 70%.

the 6L6's went in the deca with 500V on the plate, but that amp is built around 6L6's.


anyone else having issues with JJ's?
my 6L6's came from watford valves.

Title: Re: Bad JJ valves
Post by: Denim n Leather on May 15, 2010, 10:36:12 PM

JJ EL34s are among the most reliable current production valves; they are also the closest thing to a current production Mullard.

I have JJs in all 3 of my amps now and they all behave flawlessly. I would think it's either law of averages or a less-than-reputable source.

Title: Re: Bad JJ valves
Post by: Dmoney on May 16, 2010, 08:21:57 AM

they are from two different sources.
one being watford valves.
which I guess is the main place to get valves from in the UK other than Hotrox.

Title: Re: Bad JJ valves
Post by: Twinfan on May 16, 2010, 06:20:00 PM

Just bad luck by the sound of it.