J'ai pas encore tout le choix sous la main.. mais j'ai quand même un petit stock de lampes de marques différentes que je devrais bientôt pouvoir tester. Le pb c'est que c'est que des 12AX7 ou ECC83, donc kif-kif.
Mais j'ai quand même une vieille Philips ECC82 encore en état (donc 12AU7?).
J'ai trouvés 2 feedbacks d'utilisateurs de 12AU7 sur le forum de Vox :
http://www.voxamps.com/forum/t(...)=1877
Citation:
Hey guys. I have changed my 12ax7 to a 12au7 and there is a clear change. The amp is quieter. I can turn the volume up to atleast 7 or 8 and still have it relatively clean which makes it easier to use my pedals. There are alot of dynamics which take place when changing the tubes. I have also raised the pick ups on my guitar to compensate for the slight bit of volume loss after changing the tube.
Between 1-5 I get a really clean and slightly dry tone but things change from 5 onwards. The tone knob is more effective and the tone becomes more full and rich and I still as I said retain a relatively clean tone which is what I am after. I think I can waffal on forever about my findings. I have only played with this new tube for 3 hours and I think there are still alot more suprises that I am yet to experiance from this amp at different volumes.
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Like devin I have now fitted a 12AU7 to my AC4TV Combo to get more clean headroom and found similar results.
I do think there's quite a big drop in overall volume though when compared to the 12AX7, but as that extra volume from the 12AX7 was not usable to me as it got a bit to muddy for my liking I have lost nothing.
I guess it's all relative as to what you're plugging into this puppy regarding how hot your pickup's are (mine are vintage 7.4 K's) as to the overall result and I still think it sound's like a Vox with that classic chime whem you push it. When I play my Ric 12 with my Janglebox compresser using Roger Mcguin's setting's with the gain at full and the attack at 3 o'clock this amp's volume is awsome and very clean, more than enough for a small gig me think's :-)
Ce qui me rassure c'est que leur problématique semble très proche de la mienne. Actuellement je peux pas dépasser les 9h avec ma Tele montée en HB Gretsch (gratte principale). Et je monte en gros à 11h avec ma Tele standard.
Même s'il y a une perte de volume avec la 12AU7, visiblement on arrive à compenser en augmentant nettement le niveau de gain avant satu.
Kleuck : tu disais que la 12AU7 n'était pas compatible avec l'AC4, tu peux m'en dire plus? D'où tu tiens cette info? Un risque à la monter?