6V6 bias question

[daz]

Been running a pair in a marshall style amp with a 3.6k primary and 440 plate V with secondary set to 4 ohms with a 8 ohm speaker. I biased them to around 17Ma. I've always heard JJ's can take quite a bit of plate V and bias current. Any thoughts about this setup either concerning the bias voltage or anything else? I like el34's, but these things really help warm things up at low volumes so i'd like to have some peace of mind that this is a safe setup when i use it.

[The Dude]

17mA is fine and well within safe range. If it sounds good, you should be good to go.

[Chuck H]

I know that the older JJ 6v6's were reported to handle higher voltages found in vintage Deluxe Reverb amps run on modern mains voltage. The current JJ 6v6S data says max 450Vp!!! Running them into a 7.2k load seems prudent and I think you're fine.

[daz]

I know that the older JJ 6v6's were reported to handle higher voltages found in vintage Deluxe Reverb amps run on modern mains voltage. The current JJ 6v6S data says max 450Vp!!! Running them into a 7.2k load seems prudent and I think you're fine.

are u saying they changed them?

[g1]

are u saying they changed them?

I think he meant this is much higher than "traditional" 6V6 max. 350V.

The current JJ 6v6S data says max 450Vp!!!

That's for triode Chuck, for pentode it's a whopping 500V! I guess this is why some consider them a whole other tube type, somewhere between 6V6 and "real" 5881.

[daz]

I guess this is why some consider them a whole other tube type, somewhere between 6V6 and "real" 5881.

I never understood why people call it a smaller 6L6. I've used both in my amp and the 6V6 sound quite different not to mention the output is very noticeably less, or at least it seems so considering the master has to go up a good bit to equal the same given volume.

[Chuck H]

I can't say about modern production tubes because they may often be some hybrid, extra durable incarnation. Old school 6V6's don't sound the least bit like 6L6's. I really like actual 6V6's. The clipping sounds throaty and splashy. Great for blues leads and pop/rock rhythm work.

[daz]

I can't say about modern production tubes because they may often be some hybrid, extra durable incarnation. Old school 6V6's don't sound the least bit like 6L6's. I really like actual 6V6's. The clipping sounds throaty and splashy. Great for blues leads and pop/rock rhythm work.

I usually forget that when people cite power tube differences they are referring to how they sound pushed hard. I'm just noting the sound when clean. But then if i notice a considerable difference clean i imagine theres even more different pushed.

[g1]

From what I can tell, the reference about the JJ6V6 being somewhere between a 6V6 and real 5881 was with regard to power output.
Not meaning to stir anything up here, but when technical and engineering types compare tubes, they are comparing what is on paper, power out, curves, etc. Listening tests or what anything sounds like is not considered, as it is a matter of perception. How tubes sound is the realm of marketing, hi-fi and tube guitar amp enthusiasts.
Sorry for the sidetrack. As far as bias goes, the JJ's should be able to handle idling even hotter than traditional 6V6, so Daz you should be quite safe with those values.

[Chuck H]

I like to think I'm fairly particular and to be honest I just don't hear enough of a difference between tubes ran clean for it to matter (to me). Once you begin to compress the wave form each tube type starts to show more profound differences. Not that different tubes absolutely DON'T sound different clean. But it may be more about a particular tube under particular operating parameters, yada, yada. I think even most players that consider themselves very sensitive to nuances would be hard pressed to tell you what tube type they were using on a clean tone if you never showed them the amp. I mean, a sine wave is a sine wave!?! Once clipping starts it's often easy to tell the tube type unseen.

[daz]

I like to think I'm fairly particular and to be honest I just don't hear enough of a difference between tubes ran clean for it to matter (to me). Once you begin to compress the wave form each tube type starts to show more profound differences. Not that different tubes absolutely DON'T sound different clean. But it may be more about a particular tube under particular operating parameters, yada, yada. I think even most players that consider themselves very sensitive to nuances would be hard pressed to tell you what tube type they were using on a clean tone if you never showed them the amp. I mean, a sine wave is a sine wave!?! Once clipping starts it's often easy to tell the tube type unseen.

It's pretty obvious to me having swapped a million times. Sometimes whats subtle turns out to be a lot more obvious once you've heard the difference a lot. For example, i used to have a hard time really hearing much difference between a 250 and 500pf treble cap. After i put a switch in it took a little while, but now you could blindfold me and i would be my life i can tell you which is which with one ear tied behind my back. Plus if nothing more, the 6V6 is quieter and i can turn the master up noticeably more to achieve the same volume. The EL34's have a lot different midrange even clean. And the difference between say winged c and EH el34's clean is quite obvious to me. It's unmistakable. But you have to also realize not every one hears the same. There are guys who can't hear the difference between a all maple strat neck and a rosewood board one. Been playing both for years and the difference is lead pipe upside your head different to me. So it's hard to really debate what does of doesn't sound different. Maybe to you they sound the same clean because maybe you crank your amps all the time so when you don't it SEEMS they are the same because the difference cranked is so much more obvious. Who knows, but the point is different ears, different result. Especially on things of a somewhat subtle nature.

On a side note, i've been switching back and fourth between 6v6 and el34 the last few days, and i have been noticing the tone seemed to have changed for the worse and i couldn't figure out what happened. Turns out, and i have no idea how this happened w/o noticing it, but the impedance knob which has a set screw came loose enough to move, but when it did it stayed where it moved to w/o being loose. Don't ask me how thats possible, as i have no idea. The result was when it was looking like it was on 8 ohms it was actually on 16 and on 4 it was actually 8 ! Like with all the craziness in tweaking this amp wasn't enough, i really needed that to throw me off even more ! LOL!

[Alan0354]

I like to think I'm fairly particular and to be honest I just don't hear enough of a difference between tubes ran clean for it to matter (to me). Once you begin to compress the wave form each tube type starts to show more profound differences. Not that different tubes absolutely DON'T sound different clean. But it may be more about a particular tube under particular operating parameters, yada, yada. I think even most players that consider themselves very sensitive to nuances would be hard pressed to tell you what tube type they were using on a clean tone if you never showed them the amp. I mean, a sine wave is a sine wave!?! Once clipping starts it's often easy to tell the tube type unseen.

I cannot agree more about it's hard to tell the difference clean, I honestly cannot tell much of a difference between 6L6 and 6V6 when cranked at +B=450V and bias at -45V. I posted a thread in the Theory section that I have two video of the same amp, but switching from 6L6 to 6V6 with different +B and bias. One video is clean sound and the other is cranked.

In the cranked video, the first two is direct comparison between 6L6 and 6V6 in identical condition as shown. You tell me whether there is any difference.

http://music-electronics-forum.com/t35368/

[daz]

What people seem to always miss, and it's as important as anything else is feel ! You could record different tubes, or for that matter any number of amp and/or guitar related tweaks and if you put a gun to my head i couldn't tell you which is which. Put the guitar in MY hands and i'll tell you instantly. Feel is IMO MORE IMPORTANT than tone ! Yet it's totally ignored when amp and guitar related things are discussed. Filter caps for example....yes, they make little if any difference in sound. But the feel of a 20uf filter in my gain stages compared to 60uf which i've changed between many times is nite and day different in FEEL.

It's true i'm as far from being a tech as one can be and still build and tweak amps. But i've been playing a hell of a long time and my hearing and feel are light years ahead of my electronic theory. I can FEEL the difference between 6V6 and 6L6 clean easily. Probably hear it too, but the feel is easy to note.

[Gingertube]

6V6 are one tube you need not get hung up about with respect to voltage ratings.

Apart from their sterling service as SE and PP Audio Amps (even in mob ile gear) they were also used as Vertical Deflection Amplifiers in Black and White Televisions. Peak Positive Anode Voltage rating as a Vertical Deflection Amp is 1200V.

Cheers,
Ian

[tedmich]

6V6 are one tube you need not get hung up about with respect to voltage ratings.

Apart from their sterling service as SE and PP Audio Amps (even in mob ile gear) they were also used as Vertical Deflection Amplifiers in Black and White Televisions. Peak Positive Anode Voltage rating as a Vertical Deflection Amp is 1200V.

Cheers,
Ian

Yikes! Audiophiles are usually pretty shocked at EL84s taking +420V in old Traynors, but 6V6s are apparently super ROBUST!