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Line Magnetic 845 Premium bias setting. Advice needed!

Hello everyone,

I recently got a used Line Magnetic 845 premium and I need some help with bias setting.

I am not entirely sure how to adjust the bias with the knobs in the front. 
I believe the correct bias setting is 70mA for the 845 tubes (V1-V2) and 45mA for the 300B tubes (V3-V4).

Here is a photo a small video to see how its setup at the moment:

https://app.photobucket.com/u/mpolyzos75/p/243cc263-f1e0-44b8-8191-30b26d923a30

https://app.photobucket.com/u/mpolyzos75/p/947469e5-f99d-445c-ab8c-d2a8d3aba496

Are the knobs set to the correct setting?

Any ideas are appreciated. 
Many thanks.
mika75
wrm57
1,043 posts
 
mika, if you learn anything, please let us know.
stereo5's avatar
stereo5
6,388 posts
 
What about sending email to the former owner?  He/she must know how to set bias.
mika75 OP
6 posts
 
Hello everyone,

Good news!

I emailed Jonathan Halpern from Tone Imports and Charlie Schnyder from Stereo Haven and they both promptly replied within an hour or two and they both said the same thing.
Apparently the knobs in the front are for fine tuning and not of much importance. The bias is adjusted mainly by the screws on the top for each tube. As long as the needles rest on the middle dot for each tube everything is ok.
This has been bugging me ever since I got the amp and I even emailed Line Magnetic in China and still the reply I got was far from useful.
These two guys put my mind at rest. Can't thank them enough!
:-)
jjss49's avatar
Ag insider logo xs@2x
jjss49
6,612 posts
 
@mika75

wow line magnetic doesn’t supply a manual with proper instructions on how to set tube biasing?! that brand is supposed to be cream of the crop among chi-fi tube amps -- 👎

anyhow, glad you got it figured out...
mika75 OP
6 posts
 
I know,it's crazy!
But the sound the amplifier makes is so good, makes me forget these things
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