JVM and the 12AU7

  • Thread starter Thread starter ejecta
  • Start date Start date
ejecta
ejecta
Active member
Ok just got done trying a 12AU7 in the 2nd slot. Seems like it knocked the gain down some and made the range of knob more usuable. Im waitng for the tubes to cool down and put the 12AX7 back in and see if it just wasnt a figment of my imagination :D Putting the 12AU7 didnt seem to lower the gain of the clean or crunch too much either.

Will update later.
 
Ok just put the 12AX7 back in and the feedback happened much sooner on the turn of the knob. So I put the RFT 12AU7 back and I like it better. So... Ive found that for me the 12AU7 makes all the modes much more usable for my tastes and still has tons o gain.

If others once they get their JVM find the same thin,g try giving a 12AU7 a try in the 2nd slot.
 
I'm going from memory but the 12AU7 should be 60% gain as opposed to 100% with the 12Ax7. There should be a difference in gain and it may seem smoother.
 
Very cool reporting this test! That is interesting and I have a box of pres to try out.
 
ejecta, thanks for the info and cool that it works better for you.
 
>|<>QBB<
bill":3e0f9 said:
I'm going from memory but the 12AU7 should be 60% gain as opposed to 100% with the 12Ax7. There should be a difference in gain and it may seem smoother.
Click to expand...
Actually the 12AT7 has a gain factor of 60, 12AU7 is 20.
 
>|<>QBB<
ejecta":63b9f said:
Ok just put the 12AX7 back in and the feedback happened much sooner on the turn of the knob. So I put the RFT 12AU7 back and I like it better. So... Ive found that for me the 12AU7 makes all the modes much more usable for my tastes and still has tons o gain.

If others once they get their JVM find the same thin,g try giving a 12AU7 a try in the 2nd slot.
Click to expand...

Just as I suspected. :D
 
>|<>QBB<
degenaro":22601 said:
>|<>QBB<
Actually the 12AT7 has a gain factor of 60, 12AU7 is 20.
Click to expand...

Ed is correct! :D I thought Id go with lowest gain first as I thought it would give me the best idea on how much putting a different gain tube in would affect it.
 
>|<>QBB<
Santiall":d6f66 said:
ejecta, thanks for the info and cool that it works better for you.
Click to expand...

And big thanks to you Santiall for designing such a cool amp and for the advice and tech info you provided. Im really liking the amp. Is soo versatile. Im finding its much more touch sensitive than I thought. Reason is Im still exploring my new Tom Anderson and the parallel switch for the middle and neck pick ups. Im finding taking them out of parallel makes the neck much more touch sensitive and also Im thinking the 12AU7 may be making the channels more sensitive to volume changes in my picking and guitar volume knob. Again I may be mistaken about this and it maybe jsut Im finding better settings on my guitar but its working for me.

That said the JVM is different from my VHT Deliverance and I like that. Now with the JVM and the Deliverance I feel I have a real cool pallet of tones at hand.
 
yep, I put two 5751's in my Splawn modded 1987 to calm it down a bit. Congrats on the JVM.


9
 
You must log in or register to reply here.
 
Back
Top