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Is the red glow normal for 845 tubes?

Hope to get some help about the red glow from a Bel canto SETi 40 845 tubes. Is this red glow normal? Do this tubes (Sino graphite plate) suppose to glow red after about 25-30 min. After turning off the amp the glow last a couple of minutes. I am just worried that the tubes may get damaged or the amp itself. Is this glow the result of the tube dissipating heat? I know this tubes suppose to dissipate about 70W and I worried that the amp "tries" to dissipate more heat that they can handle. Thanks in advance for your help.
tiofelon
stanwal's avatar
stanwal
3,147 posts
 
Red glow in morning, audiophile take warning! Sorry, sometimes I just can't help myself.
tiofelon OP
59 posts
 
I just got an answer from Mathew Cramer from Bel canto. He says that "the red glow is normal for this type of design" (SETi 40). So that settles everything down. Thank all for your help. Tiofelon.
brf
1,715 posts
 
What did he say about using a low dissipation (70w) 845s in the SETi40? That is the real question you should ask. If the SETi845 is auto biased for a standard 845, then the amp is over driving the Sino.
tiofelon OP
59 posts
 
Good point Brf! He did not said anything regarding the low dissipation. I will ask him if the SETi 40 is biased for a standard 845 tube (100 W dissipation).
tiofelon OP
59 posts
 
I got another answer from Bel canto stating that the dull red glow from the graphite plate is normal and that the amp can drive just fine the 845 low dissipation tubes. Bel canto did not said anything regarding the amp bieas for a hight dissipation tube or for a low one. Thanks again Brf.
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