Moderators: zaphod_phil, Daviedawg, Graydon, CurtissRobin, colossal
The gain of an EF86 pentode is way higher than a 12AX7's triode. The triode has again of 100. IIRC the EF86 somewhere in the thousands, although you never actually see all of that in a real-life circuit. Because of this EF86s are very popular for use with a James/Baxendal tone stack, as it is very effective, but attenuates the signal a hell of a lot.Wayne_Alexander wrote: I have found that the gain in that channel is insane with the stock 18 watt phase inverter wiring
If the prices are similar, I'd try the Ruby - I'm so-so on current production Sovteks. With the Ruby, you never know where it was manufactured when you order it, but at least you may get a good one.Attilio wrote: Now I have to find a EF86... I will order it to an italian website, which sells sovtek and ruby tubes EF86s, with a little price difference: which one is better?
The outrageous gain one can get from the EF86 can be tamed somewhat by use of a more lossy and more useful tone stack, such as the James/Baxendal or the Vox stack - which is kind of appropriate here. That way you get both treble and bass controls, and still tons of gain left over. I'm fascinated by your comments about the PI mods. I was seriously considering doing them myself, until I realised how very Vox-like they were, and to me Voxes are far too clean - think Beatle's 'Hard Days Night'. Brian May has to play his AC30s cranked flat-out and with a booster pedal on the input, to get his distortion. So like I said I'm fascinated that you're still getting dirt with the PI mods in.Wayne_Alexander wrote:with the EF86 that channel is a lot louder and dirtier than a stock one with a a 12AX7, even with the revised phase inverter wiring. Without that the EF86 is almost uncontrollable, and is dirty at .5 on the volume setting. It just means that I'll use the EF86 channel for the loudest, dirtiest stuff, and the 12AX7 tremolo channel when I need tremolo and need to go only to, say, AC/DC levels of gain.
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