RA-100. Can the brightness be tamed ?

[JOEY B.]

Thanks for that information. I have some Penta 12ax7s, but so far I have not really used them as most of my amps have needed help up top. Now that you have reminded me, I might try them in the JCM and see what happens.

FWIW, the Penta 12AX7 and 12AX7M are two different tubes, http://www.dougstubes.com/preamp-tubes/12ax7-ecc83-7025.html?brand=8 but I bet both sound better than the stock MESA-branded JJ's. Bare walls in an amp room could be painful if it were small enough.

 

[J.J]

I wasn't sure which Penta tubes I had anyway, but checked them and they are not the "M" ones. Interestingly the description on Dougs side mentions "rolled lows" for the "M" Pentas.

I did try one of my Penta tubes in the JCM (replacing whatever the tube was that was in it when I got it 18 years ago) and was really suprised how much better it sounds. Way more gain and am now happily runing the trebble at 4 instead of 2 8)

There is no way to know without trying if the Penta tubes would have the same effect in the RA or not, but it does look good.

Another question, what happens to the tone as the master is turned up on the RA. I guess I am most interested the effect for vintage low mode. The ED really brightens up when the master is raised to 9:00 (seriously loud) and appears to have more gain, although I think that is just a perception thing due to extra high end content. Power tubes clipping is happening by 10:00. The RA seemded more consistant across its master range. Anyone able to comment on this ?