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Esoteric Audio Research V20 tube layout

Hi Folks - I have had an EAR V20 for many years now and have enjoyed it very much. It came time to re-tube and I've made a pretty dreadful mistake. I cannot recall which tubes go into which slots. I know that there are ten 12AX7's for each output stage and they occupy the front 10 spaces on each side but I am not sure where the remaining tubes go which are a mix of 12AU7's and some more 12AX7's.

I don't have any owner's manual so I cannot access the information if it were on those pages.

I do have an inquiry out to Dan Meinwald but I thought I'd also ask here, as well.

Thanks in advance for anyone's help! :-)
ciggycig
jasonbourne52's avatar
jasonbourne52
2,863 posts
 
That is an interesting tube amp! I saw pictures and read about it in HiFi News years ago. I assume the front end 12AX7's are the input tubes (one per channel) and the 12AU7's are the phase-splitters/drivers for each output stage. 
jasonbourne52's avatar
jasonbourne52
2,863 posts
 
If you remove the bottom cover you can trace the signal path from the left and right input jacks to the two sockets for the 12AX7's. Then further tracing from those two sockets will lead to the 12AU7 sockets. How many sockets total in the front end? 
jasonbourne52's avatar
jasonbourne52
2,863 posts
 
I was amazed that using ten 12AX7's in parallel per channel can yield 20 watts! Not a tube one thinks of as an output tube because of its small size and limited plate dissipation!
jasonbourne52's avatar
jasonbourne52
2,863 posts
 
Tell me the number of 12AX7's and the number of 12AU7's in the front end. So I can have a clearer picture of the overall tube layout.
ciggycig OP
3 posts
 
Thank you for your answers. There are a grand total of 30 tubes on this amp! 15 on each side. 
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