bohemian 1,921 Posted April 8, 2020 How do you valve guys rate jj12au7s? I have 4 which I am rolling in the central positions on my PL Dialogue Premium Monos in place of stock PL valves. (preamp has mullards in central positions) The midrange seems very good but I wonder if I could do better? Can't run to mullards at £70 each, but maybe look at gold lion or brimar? Love my valve amps but I am confused about relative quality of valves and don't want to spend a fortune tube-rolling (6 12au7s in pre and each mono!) I must say I am loving the PL EL34s and I have some 6550s when I fancy trying them. Quote Share this post Link to post Share on other sites
JANDL100 1,386 Posted April 9, 2020 I've a PrimaLuna Prologue 5 power amp. It came with Philips JAN 12AU7 and 12AX7 input valves which were OK but things improved noticeably when I replaced them with TAD valves. I've not tried JJs in the PL but I generally prefer TADs to them. I also now have a set of Psvane and they are good, too, pretty much equivalent to the TADs, I can't say I prefer one over the other. The amp came with Edicron 6550 power valves, I swapped them for TAD el34 and was impressed by the extra clarity. I'm not usually a fan of el34, but the TADs worked really well. I then tried KT120, heh, the search stops here! Superb. They are tall, though, and just fit in the valve cage if it's on tippy toes! Quote Share this post Link to post Share on other sites
mr.me 354 Posted April 9, 2020 Recently acquired a pair of PrimaLuna Prologue Six monoblocks that had Electro Harmonix 12AU7's replaced them with RCA clear tops for a good improvement in sound quality Quote Share this post Link to post Share on other sites
ESK 152 Posted April 9, 2020 Its a while since I used that particular tube. However, I quite liked the old Ei Elite Gold Pins or Electro Harmonix Gold pin varieties. Quote Share this post Link to post Share on other sites
bohemian 1,921 Posted April 9, 2020 (edited) with the jj tubes I am getting clearer highs and upper mids, which may help me because of age-related hearing loss. The bass is still great. I think I will leave them in for a while and then maybe revert to my previous configuration. I'll get the piggy bank out to save for something like the mullards or brimars. Edited April 9, 2020 by bohemian Quote Share this post Link to post Share on other sites
JANDL100 1,386 Posted April 9, 2020 (edited) The TADs would give you the sophistication and subtlety of the Mullards imo but will retain the upper freq clarity of the JJ. The Mullards /Brimar are a bit "cumfy" and smooth in comparison. Edited April 9, 2020 by JANDL100 Quote Share this post Link to post Share on other sites
paulkebab 72 Posted April 9, 2020 To my ears the Mullys make the midrange a bit softer, after that well we're all experimenting Quote Share this post Link to post Share on other sites
