Help with TS 6550 bias drift

  • Thread starter Thread starter Wagster
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Wagster

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I've played several gigs with the TS 6500's and everytime I check the bias it has changed. I set it yesterday and it was 47mV, today it's 48.6mV :confused:
 
Hmmm, maybe I should check mine too!! :lol: :LOL: Weird. I'll check here tonight and see what it is now.
 
I'll check mine too.....oh wait,they're in NY :lol: :LOL: I didn't have any drift problems that extreme,maybe 3 or 4mvs but not 30 :confused:
 
jmgman69":1nbrzh45 said:
I'll check mine too.....oh wait,they're in NY :lol: :LOL: I didn't have any drift problems that extreme,maybe 3 or 4mvs but not 30 :confused:
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I meant 48.6 :lol: :LOL:
 
I'm using Svet 6550's and mine did the same thing at first. Give them about 10-15 hours and they will be more consistent.
I have mine set at 46.
 
That is normal! Remember, tubes are far from perfect and the current they are fed can change depending on where you play. Drifting is fairly normal.
 
Yeah, mine drifted too. But, I picked these up used from a guy who pulled them from an amp he got. Well, they are like 13 or so apart!! If I set one to around 46, the other is like 33!! :no: My fault for trying to save some coin. I'm going to e-mail Doug and see if he can match each one with another, so I'll have two matched pairs. Don't know if he'll do that or not, but worth an e-mail to him. :lol: :LOL:
 
It's not the difference between the two tubes that bothers me. It's the fact that everytime I turn on the amp I get a different bias reading. This is even after it has warmed up for 15 minutes. One time it's 47MV and the next time it 37mV..ect.
 
I'm still having the same issue. It's only after I turn my amp off and let it set a while. It never returns to to where I biased it last. If I don't turn the amp off it holds it's bias.
 
jmgman69":2vbpwbtt said:
What do you plug it into???Power conditioner etc.
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A wall outlet. It also does it on my gigs so it's not just my home power.
 
Wagster":2fli133f said:
jmgman69":2fli133f said:
What do you plug it into???Power conditioner etc.
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A wall outlet. It also does it on my gigs so it's not just my home power.
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Get rid of the wallwart and get something like a Furman Power Conditioner. Every amp's bias drifts, your getting obsessed because you can actually check the bias.
Does it sound good? Then quit playing with it. :lol: :LOL:
 
Doubleneck":ofatjpil said:
Do you like how the amp sounds?
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The amp sounds great but sometimes it sounds cold and I check the bias and it's too low. A quick bias adjustment turns it back into a tone monster. It's a little annoying to keep having to readjust the bias. The 5881's didn't do this but sounded nowhere near as good to my ears as the TS6550's.
 
Wagster":28vec4a8 said:
Doubleneck":28vec4a8 said:
Do you like how the amp sounds?
Click to expand...
The amp sounds great but sometimes it sounds cold and I check the bias and it's too low. A quick bias adjustment turns it back into a tone monster. It's a little annoying to keep having to readjust the bias. The 5881's didn't do this but sounded nowhere near as good to my ears as the TS6550's.
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I think it's just an inherent problem with 6550's? I'm on my 3rd set with 6550's and they all drift? I bought them from thetubestore.com. The first set, one tube didn't even work, the second set, I couldn't get one tube to bias below 67mAh, this set is the most consistent and after some use is starting to settle down. At least thetubestore was really cool and has swapped them all out. The 5881's, GTE34L's and SED Winged C EL34's don't drift on my amp either.
 
As easy is it is to check,Fuck it,play them to there DEATH!!!!!!!!!!!!I absolutely loved the TS 6550s in the Mod50!!!!
 
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