In this video (starting from 7:30) they discuss that the 2023 version of Bad Cat Black Cat had one significant chance: the EF86 tube was replaced with 12AX7, but they tweaked the circuit that 12AX7 would still sound like EF86.
Any ideas what did they do to achieve it?
I have no idea if it actually does sound like EF86...if it does, I want similiar changes to my amp. I have a older Cub 2, which has a rotary switch tone (ala Matchless), but it has 12AX7 instead of EF86.
https://youtu.be/w6OveFZ2Kf0?si=cDQbiwJre7Ikts0X
"EF86" sound from 12AX7 tube?
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- martin manning
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Re: "EF86" sound from 12AX7 tube?
Seems like they just got tired of dealing with the EF86's shortcomings. If I wanted to get rid of the EF86 while keeping its high gain, I would replace it with a twin triode configured as a cascode.
edit: thinking alike, I guess.
More discussion here: https://ampgarage.com/forum/viewtopic.p ... 14#p378314
edit: thinking alike, I guess.
More discussion here: https://ampgarage.com/forum/viewtopic.p ... 14#p378314
Re: "EF86" sound from 12AX7 tube?
I don't actually need the massive gain of EF86, since I play mostly with clean tones. IME there are just some magical harmonics in the EF86 sound that is often missing with 12A_7 preamps.
Re: "EF86" sound from 12AX7 tube?
For baffling (un)reason, in the "voodoo of MI amps" bubble, the equation "gain == distortion" and "gain != clean" holds majick powers. Not strictly so, though "hi-gain" designs inevitably rely on several layers of stacked gain. That said, tuning a cascode to twinkle like some small signal pentodes proved somewhat elusive, at least according to reports by those venturing few who've walked that circle looking for a heffalump. Maybe Bad Cat has?
Best ..
Re: "EF86" sound from 12AX7 tube?
The obvious fix is to use a different pentode, say the 5879, which was made for audio. You'll see it in several boutique amps. It is my favorite to use as a distortion generator, but i use it as an input tube also. You'll recognize the sound.martin manning wrote: ↑Sat Jan 06, 2024 3:11 pm Seems like they just got tired of dealing with the EF86's shortcomings. If I wanted to get rid of the EF86 while keeping its high gain, I would replace it with a twin triode configured as a cascode.
edit: thinking alike, I guess.
More discussion here: https://ampgarage.com/forum/viewtopic.p ... 14#p378314
Tube junkie that aspires to become a tri-state bidirectional buss driver.
Re: "EF86" sound from 12AX7 tube?
many pentodes are good for audio.. i also like EF86 and there is no any problem there if the tube is made well (using german brands)
Re: "EF86" sound from 12AX7 tube?
Actually the Top Boost Vox installed later, comes pretty close to the tone of an EF86. (set the Treble and Bass Pots to zero or very low)