Announcement
Collapse
No announcement yet.
Orange OR50 40th Anniversary Bias?
Collapse
X
-
Looks like it would be the bias pot. I see the grid wires from the octal sockets going to that part of the board. Just looking at the nearby components, I'd say yes. To be safe, you can try tweaking it with the power tubes removed and monitoring pin 5 for change.
- Likes 1
-
Other people have reported them having adjustable bias. Are there any other trim-pots in there? Do you find negative DC on TP3 or 4?Originally posted by EnzoI have a sign in my shop that says, "Never think up reasons not to check something."
Comment
-
Originally posted by misterc57 View PostYes so that is the only trim pot I can find on the board and it does control bias.
EL34 reading bias v -29 current 49mAOriginally posted by EnzoI have a sign in my shop that says, "Never think up reasons not to check something."
Comment
-
Originally posted by g1 View Post
That seems a lot of current if for a single tube. But -29V isn't much bias, something like -38V may be more appropriate, depending on other power tube voltages.
I am going to install new pair of Black Sable EL34. Will dial up the bias and report back with voltages and current.
Thank you
Comment
Unconfigured Ad Widget
Collapse
Comment