Old followup to lab guidelines

dayneger · « **on:** 22 Jan 2004, 08:04 pm »

Hi John,

Could you briefly clarify what the difference is between The Lab and Constructor's Corner? I don't understand the need for 2 areas yet, and their guidelines overlap with DIY, construction, etc.

The Lab--The technical side of audio. How and why our equipment works, construction, and DIY.

Contructor's Corner--Threads devoted to construction of audio equipment.

Cheers,

Dayne

JohnR · « **Reply #1 on:** 22 Jan 2004, 10:34 pm »

Um, yes, haven't written the Guidelines for that one yet. It will all become clear (I hope!!) soon

ratbbb2 · « **Reply #2 on:** 12 Jul 2004, 10:30 pm »

Ok so I know I should have a grip on tubes if I own them but up until now I haven't had any thing go wrong (other than a bad recterfier valve)
I had Groovetubes EL34 (JJ, Penta...) in the amp and one of the quad went bad (started to glow and poped the fuse). I changed the fuse then played with the biasing and switched tubes to come to that conclution. ones I replace the old(er) EL34 for a set of 6CA7 (Ei big bottle) I can no longer get the recomended voltage of 1.56 in fact the highest it goes is 1.24v on one side and 1.21v on the other . Is there a reason for concern once I bias them at 1.15v or is it just a lower output tube?
Thanks Roger