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Replace 12AU7 with 6SN7 ?

Hello Guys !
I own Ayon Triton (integrated, but use only the Power section) with 6 12AU7 an 8 KT88.
I read in some threads that the 12AU7 can be easily replaced by 6SN7 (which I have 4 of them and enjoy in my Preamp).
This to be done by a "socket converter" (available on eBay) which internally makes the required wiring for the filaments to allow the replacement.
The reported results were positive.
I asked the manufacturer the same question and the answer was "straight forward", "quote":

DO not use 6SN7 or any others as the original types are. IMPORTANT – otherwise your amp will be destroyed.

Does anybody have any experience with replacing drivers like 12AU7 to 6SN7 in Pre or Power ?

thanks.
amiglick
rar1's avatar
rar1
1,784 posts
 
With all due respect, do you think that anything that any of us could offer as an opinion to you would mean more than what the manufacturer said to you as fact? I am not going out of my way to be rude, I would just think that the manufacturer's word would trump anyone else's.

Rich
tls49's avatar
tls49
1,351 posts
 

+1 for Rich, I agree. There are so many different 12au7's available. It makes better sense to just try a different 12au7.
yogiboy's avatar
yogiboy
5,726 posts
 
I could be wrong but I thought the 12 and 6 mean the voltage of those tubes!
mofimadness's avatar
mofimadness
4,994 posts
 
Yogi, that is correct as I understand it also. I can't see how you could use a 6 volt tube in a 12 volt position even with an adapter, unless that adapter also steps down the voltage?
ghostrider45
449 posts
 
12AU7 and related 9 pin triodes have a center tapped filament that can run on 12 or 6 volts depending on whether the segments are wired in series or parallel. In most amps they run on 6 volts as that saves having a special 12 volt secondary winding on the power transformer.

6SN7 draws 600 ma of filament current. A 12AU7 draws 300 ma filament current in parallel mode (6 volt operation).

Simply replacing 12AU7s by 6SN7s would double the filament current drawn (3.6 amps vs 1.8 amps for 6 tubes). That could easily burn out the power transformer if its rating is marginal.

I would follow the manufacturer's recommendation as mentioned above.
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