It is currently Tue Mar 17, 2020 1:50 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 3 posts ] 
Author Message
Post subject: '65 Twin Reverb BIAS
Posted: Mon Jan 04, 2010 12:45 pm
Offline
Hobbyist
Hobbyist

Joined: Tue Aug 25, 2009 4:32 am
Posts: 9
Hello guys, today I found where the bias pot is located in a '65 Twin Reverb Reissue. I found that my tone was a little flat, especially with pedals, sometimes fuzzy (and I don't use exotic pedals, I'm talking about a standard tubescreamer), so I thought i'd give the bias pot a gentle turn clockwise and hear the difference. Then I thought: I can't tell if clockwise means higher bias or lower bias, so I gave the pot a full turn clockwise and then counterclockwise watching the tubes and I found out they lighted up when I turned counterclockwise (bare in mind that the amp is closed and i'm sticking the screwdriver in the hole behind the small transformer). So I turned the knob back to its original position and turned it counterclockwise a notch, now pretty much sure that it raised the bias current a bit. I'm planning to have it set by a tech (or buying a probe), but in the meantime please tell me if I made anything wrong. I upped it a bit also because i felt like the tubes weren't working too much, they were not too hot when cranked.

PS.: by "lighted up" when turning the pot i meant that the blue light inside the tube went from very dim to bright, they did not start to glow red!


Top
Profile
Fender Play Winter Sale 2020
Post subject:
Posted: Mon Jan 04, 2010 6:55 pm
Offline
Professional Musician
Professional Musician

Joined: Fri Jun 26, 2009 6:53 pm
Posts: 2252
Location: Harvard IL
Camazza, how did the amp sound? If the plates on the tubes don't glow orange when you crank up the amp you're probably OK, until a tech can check it. A small increase in the idle current( which you did) should be fine. Art

_________________
None of Us are free, if One of Us is chained !


Top
Profile
Post subject:
Posted: Tue Jan 05, 2010 1:31 am
Offline
Hobbyist
Hobbyist

Joined: Tue Aug 25, 2009 4:32 am
Posts: 9
The amp sounds marvelous, before the little increase the tubes were barely warming up.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: