Other Amps

tweaky tube questions


What kind of difference would there be between a single 6L6 (Fender style build) ..which you almost never see, and same amp w 2 6V6s. Really just the sound... of course there's all kind of tweaky tube specs that can be recited.

Similarly I wondered the same thing about a single 6BQ5 going against a pair of the lowly and forgotten 6AQ5...

Lastly, the next demented idea is to stuff a 15 in to Musicmaster bass amp -- wondered what the difference would be between the 2 6AQ5 version of this amp and the later 2 6V6... I think they came in that order.

And for all of this, it's about normal clean sound around 5, not not the dimed distortion scene


Depends on a lot of things. Are you running the pairs in parallel single ended Class A or push-pull Class AB? The 6AQ5 is a very cool tube, forgotten or not. Gibson used them in their Crestline amps. They can be coaxed to be clean.

Besides the big difference in harmonics, two tubes in push-pull usually can achieve more clean headroom. The 6V6's tend to have more headroom than the 6AQ5's, which run at lower plate voltage. The great thing about the 6AQ5 is that there are MILLIONS of NOS out there for the taking. The 6005 is a high quality military version of the same tube, and again are dirt cheap.


Thank you for this info. I am intrigued by the 6AQ5 (and 6005!) Musicmaster Bass amp -- might troll for a clean one. Same chassis as VibroChamp w/. plenty of room for tweakin'

This custom 2 6V6 build I have is tonally versatile but way too loud for one specific purpose I have. Still, it's a keeper.


Single ended (one tube) will have lots of even order harmonics when you push it, even if you're using a lot of feedback. A push-pull amp, if properly balanced, will cancel the even order harmonics and produce lots of odd-order, which is more musical. Single ended amps can still sound cool, but a 6L6 isn't a very god choice, harmonically speaking. 6BQ5/EL84's and 6V6's can be run single ended, without feedback and still sound really good. Push-pull will always sound smoother though.


Aha -- thanks BZ for this perspective. It was just kind of academic, although I am still interested in the single ended 6BQ5 Thomas Vox Pathfinder, if I could find a clean one.



This is a tough question because you are changing two variables at the same time. Push pull vs. single ended and 6L6 vs. 6V6.

In my opinion 6L6 tubes sound more mid scooped than a 6V6 played clean. All things being equal. Like say popping a 6L6 into a Champ instead of a 6V6

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