6L6 Vs. EL84

[markb]

Let's see now. I like Fenders and I like Voxes. Both/either, please.

[jim p]

I think part of the sound difference maybe due to the transformers used. I saw this in a posting about transformers at Tales from the Tone Lounge. Also if the amplifier was designed with feedback as most Fender amps are (6V6 6L6). I think most English amplifiers (EL34 EL84) did not use feedback and used over designed (big) output transformers. While Fender amplifiers look to always have feedback and somewhat smaller transformers. The feedback would actually allow use of a smaller transformer by reducing output impedance so lower reflected impedance needing less inductance for bass response. But if you are going to drive the amplifier into distortion then feedback will make the transition into over drive abrupt causing another tonal difference between the amplifiers. So it may not be a simple question of the tube in the amplifier but the design of the output stage of the amplifier and the transformer used.

[tot_Ou_tard]

Jim,

Whatdo you think the results would be if you took an AC30 but added negative feedback or removed the negative feedback from a blackface Fender?

My Gries 5 is a single ended class A blackface champ style with a 6V6 but no negative feedback. (You can also dial out the tonestack for a Tweedy vibe).

BigG's Swart is a Tweed-type circuit with no negative feedback, but it does have a switch allowing one to switch in some negative feedback.


As far as the original question, I thought that it was common knowledge that EL84s break up sooner than 6L6s regardless of transformer or of whether there was negative feedback. Is this not so?

[jim p]

I am not sure of the point at which the two types of tubes break up but I am sure there are differences. One big difference between the two types is the 6V6 and 6L6 are power beam tubes so they have no suppressor grid and are actually a tetrode not a pentode as the El tubes are.
With regard to feedback if you are after a clean sound and an increase in bass response it would be worth trying. In the mod #201 posted for the Crate V5 I explained how to add it to the V5 with a pot to control the level. In the posts at 300 Guitars they were taking the feedback out of the Champ 600 and making tone stack mods for a Vox sound so? To add feedback you need to know the over all gain of section of the amplifier you are going to add it to because your feedback gain needs to be less then this. Then need to use the proper phase so you don’t wind up with positive feedback and make an oscillator out of the amplifier.
Just wanted to bring up the point that the tonal differences may not just be due to the tubes.

[tot_Ou_tard]

One big difference between the two types is the 6V6 and 6L6 are power beam tubes so they have no suppressor grid and are actually a tetrode not a pentode as the El tubes are.

I've certainly heard these words before, but I don't have a clue as to what they might mean.

[P.J.]

Let's see now. I like Fenders and I like Voxes. Both/either, please.

The Egnater amp w/ both would be right up your alley then.

=-) PJ

[markb]

The Egnater amp w/ both would be right up your alley then.

=-) PJ

But the Trademark 60 does it with much less fuss (and weight)

[TS808]

My Fender Bandmaster (6L6) and my Delta Blues 210 (el84) have distinctly different sounds....I wouldn't say one is "better" than another. It just depends on what you want. Most of the time, you'll find 6L6's in higher wattage amps (e.g., 40 watts and higher) whereas EL84's are used alot in lower wattage amps (e.g., Blues Jr., 30 watt amps, etc.). A nice 50 watt El84 amp is the Peavey Classic 50.

I don't know that one tube is "better" than the other...it's just a matter of preference.