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Dual Rectifier Solo Head

Blackjack30

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Apr 9, 2016
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322










Killer amp, anyone know if i can stick a non-MESA matched quad of Tungsol 6L6's in there without any bias problems ?
 

thejaf

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Oct 27, 2006
Messages
527
Your best bet is to take the amp to a qualified technician. Many ages ago I had a MarkIII, which was fixed bias cold without any adjustment pot (just a resistor). You could "swap" power tubes without bias adjustment because it was essentially factory fixed to run cold. This amp may be the same, or it could have regulators to control bias current.
 

Blackjack30

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Apr 9, 2016
Messages
322

-4db on the hot plate, tube rec setting, "Bold" switch on, very SLO-ish.
 
Last edited:

PaulD

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Jun 25, 2007
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675
Killer amp, anyone know if i can stick a non-MESA matched quad of Tungsol 6L6's in there without any bias problems ?

There is no bias adjustment on these, they are factory set using fixed resistor values. Provided the replacments are a matched set it should be no problem, just check to make sure they are not red-plating and you should be good to go. If I remember correctly there is a switch to set the bias for either 6L6's or EL34's so you can user either and select the correct bias with the switch.
 

Blackjack30

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Apr 9, 2016
Messages
322
There is no bias adjustment on these, they are factory set using fixed resistor values. Provided the replacments are a matched set it should be no problem, just check to make sure they are not red-plating and you should be good to go. If I remember correctly there is a switch to set the bias for either 6L6's or EL34's so you can user either and select the correct bias with the switch.
Yes thanks, i was able to find a tube vendor thats sending me the right 6L6's.
 

renderit

Well-known member
Joined
Jan 19, 2009
Messages
10,969

-4db on the hot plate, tube rec setting, "Bold" switch on, very SLO-ish.


That sounds awesome! But..........Thank God not all amp manufacturers do it the same way as Mesa or we'd have a silicone shortage! Damn! The boards on that thang are packed! My little V/25 is the same way. Sounds great as well but damn!
 
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