EL34s vs 6L6s

[Torment Leaves Scars]

I have a Peavey 3120 head with EL34s and I just can't get that really dark tone out of them that I'm looking for.  For about two weeks (before it blew up) I had a Randall RT-100 head and that had 6L6s.  I really loved the sound of that head.  Don't get me wrong, I really like the sound of my Peavey 3120, too, but I just want a darker sound.

I've heard conflicting stories.  I've heard from some people the sound isn't really determined by the types of tubes but more by the rest of the parts; in other words, the tubes are secondary to the sound.  :dontknow:

I'm not only looking for a darker tone but I'm looking for a little more resonance or "thrum."  would the 6L6s help me achieve what I'm after or would it be a waste of money?

 

[Patrick from Davis]

I am going to say that you would be better suited finding preamp tubes that are darker.  The EL34's will be more of a classic rock sound, and the 6L6's will be more of a metal sound.  That is a generalization, yes, but here is why.  The EL34's will have more power amp distortion, and sound looser, the 6L6's will have a tighter sound.  For Metal, the power amp should be a tighter sound to be able to reproduce the speed of the music with more clarity.  For classic rock, it is a looser sound where speed is not a huge factor.  Again, generalizations...  The pre amp will give you the darkness, the power amp will make it a lot louder.  I have found that the Sovtek 12AX7WB darken things quite a bit.  Pop one of those in as the first tube and see what happens.  It should set you back less than 20 bucks, so it is an easy try.  If you don't like it, sell it to a buddy as a back up tube and get most of your cash back.
Patrick

 

[swarfrat]

Much of the generalizations about EL-34 vs 6L6's is a bit unfair. Lots of folks do abuse 6L6
's but i think many of the comparisons assume the 6L6 amp is not disorting the power amp. Every tube is beaauuuutiful in its own way. But.distortion always adds harmics. The transformer/speakers, and traditions of drive and impeadance mismatching we associate with different tubes probably matters more than the tubes themselves.

 

[Torment Leaves Scars]

I am going to say that you would be better suited finding preamp tubes that are darker.  The EL34's will be more of a classic rock sound, and the 6L6's will be more of a metal sound.  That is a generalization, yes, but here is why.  The EL34's will have more power amp distortion, and sound looser, the 6L6's will have a tighter sound.  For Metal, the power amp should be a tighter sound to be able to reproduce the speed of the music with more clarity.  For classic rock, it is a looser sound where speed is not a huge factor.  Again, generalizations...  The pre amp will give you the darkness, the power amp will make it a lot louder.  I have found that the Sovtek 12AX7WB darken things quite a bit.  Pop one of those in as the first tube and see what happens.  It should set you back less than 20 bucks, so it is an easy try.  If you don't like it, sell it to a buddy as a back up tube and get most of your cash back.
Patrick

Not really knowing ANYTHING about swapping tubes, I understand I would have to get the head rebiased for the EL34 to 6L6 swap.  Would I have to do the same with a 12AX7WB tube?  I believe it runs 12AX7s now in the preamp section.

 

[Patrick from Davis]

Nope, nothing to do but swap them in and out.  They are "cathode biased."  =CB= gave a very nice description of it, quite in depth, a couple of years back, but it is a self adjusting setup so the preamp tubes can be plug and play.  If you are in the States, I suggest the Tube Depot for tube, and the Tube Store if you are in Canada.  Both places are great to work with I have found. 

Here is some more info, but not what you asked for.  The power tubes have an adjustable fixed bias.  Peavey amps generally have that fixed and not adjustable.  This means that the power tubes are under biased.  New power tubes never burn up from being over biased because they are factory set very low (25-40% of Imax).  There also can be odd crossover distortion that happens when biased like this, sounds odd...  You can have a tech add a variable resistor to the amp to allow it to be biased properly for the power tubes in it.  A general non technical description of what happens is, the sound blooms when you get to a proper bias.  You need to have some equipment to bias things properly, so for most it is something a tech does.

Again, a lot of this is general description stuff and individual amps models will behave the way that they do, at times not following the generalizations.  But the overall description is reasonable.
Patrick

 

[Torment Leaves Scars]

Nope, nothing to do but swap them in and out.  They are "cathode biased."  =CB= gave a very nice description of it, quite in depth, a couple of years back, but it is a self adjusting setup so the preamp tubes can be plug and play.  If you are in the States, I suggest the Tube Depot for tube, and the Tube Store if you are in Canada.  Both places are great to work with I have found. 

Here is some more info, but not what you asked for.  The power tubes have an adjustable fixed bias.  Peavey amps generally have that fixed and not adjustable.  This means that the power tubes are under biased.  New power tubes never burn up from being over biased because they are factory set very low (25-40% of Imax).  There also can be odd crossover distortion that happens when biased like this, sounds odd...  You can have a tech add a variable resistor to the amp to allow it to be biased properly for the power tubes in it.  A general non technical description of what happens is, the sound blooms when you get to a proper bias.  You need to have some equipment to bias things properly, so for most it is something a tech does.

Again, a lot of this is general description stuff and individual amps models will behave the way that they do, at times not following the generalizations.  But the overall description is reasonable.
Patrick

Thanks for the info!  Any idea of how much something like this would cost to get everything with a head adjusted?

 

[bagman67]

Bench time generally runs 75-150 per hour; if you just need a rebiasing, there's often a flat fee for that.  Check with amp shops in your area.

 

[Torment Leaves Scars]

Bench time generally runs 75-150 per hour; if you just need a rebiasing, there's often a flat fee for that.  Check with amp shops in your area.

Will do!

 

[Patrick from Davis]

There are kits for the variable resistor bias mod, but any competent tech should be able to just buy the parts on their own.  I like to use locking pots, there is a nut that tightens down the shaft.  Trust me, those things will get "adjusted," if you don't lock them down.  The price is hard to say, lots of variables.  Shop, person, amount of work...  Hard to say.
Patrick

 

[mullyman]

I have a question here, can you take EL34's out and put in 6L6's? Are the sockets the same? If so, does that mean you can take the tubes out of a Marshall and replace them with tubes from a Dual Rectifier?

As for the amps, FWIW, the Peavey 6505 is the 5150 re-numbered. I had a 5150II and that amp is a beast and a half. It will ride right alongside a Mesa Dual Recti just fine.

I just recently turned 45 years old and my ego and my back have told me that I no longer need 100w of pure raw power running through a 4x12 cabinet. Talk about overkill. I have sold my Dual Rectifier and purchased the new Mini Rectifer (25w) with a 1x12 Mini Rectifier slant cab. Piping it through the PA gives me plenty of sound. I've done gigs with this tiny little thing in places that hold over 500 people and it's perfectly fine......and it doesn't break my back loading in and out. The head fits in a shoulder bag and the cabinet is only about 25 pounds or so. Couldn't be happier.
MULLY
yes, the Mini Recti has that Mesa Boogie growl in spades

 

[swarfrat]

Sockets are the same, but EL34's require a LOT more heater current, and have lower drive requirements / bias voltage. And different output impedance. There are amps designed to use either, but it's not a direct swap in most cases.

 

[Torment Leaves Scars]

Sockets are the same, but EL34's require a LOT more heater current, and have lower drive requirements / bias voltage. And different output impedance. There are amps designed to use either, but it's not a direct swap in most cases.

Yes, the Peavey 3120 was designed to use both but I think it mentions in the paperwork that it would have to be rebiased for the swap.

 

[Re-Pete]

Not trying to talk down to anyone, but remember too, that the power tubes are just a part of the total sound you would hear. The preamp tubes, the circuit design, the speakers, etc. all have some colouration & direction the eventual sound will take.
If your amp has a fixed bias that may require a tech to service the amp if you install EL-34s, maybe it would be more practical to look at the sound before it enters the the power stage: ie... the preamp tubes. Is there some way the sound's tone could be turned to the direction you want it to be, using a preamp tube swap? Lower powered types like 12AT7 instead of 12AX7s for example?  :dontknow:

 

[thebutcher85]

I've got a 3120 head and I get "dark" metal tones out of mine, mine has JJ tubes all around (preamp, and JJEL34's in the power), I have the tone knob backed off to about 10'o-clock, mids cranked to 3 o'clock, and bass at 2 o'clock, and then I have a digitech bad monkey overdrive boosting the front end of the amp for BR00TALZ metalz. (Volume up really high, gain all the way off, tone knobs to taste) I use the above settings for old school thrash, metal, and modern metal & hardcore (I just use different guitars tuned differently).

Don't waste your money on 6L6's, crank the mids & bass, and boost the front end of your 3120 with an overdrive like a tubescreamer or such like, you'll get the darker metal to Ed you're looking for.

(Also, I use 300k volume pots on all my guitars, it gives them a slightly darker tone that I like)

 

[Torment Leaves Scars]

I've got a 3120 head and I get "dark" metal tones out of mine, mine has JJ tubes all around (preamp, and JJEL34's in the power), I have the tone knob backed off to about 10'o-clock, mids cranked to 3 o'clock, and bass at 2 o'clock, and then I have a digitech bad monkey overdrive boosting the front end of the amp for BR00TALZ metalz. (Volume up really high, gain all the way off, tone knobs to taste) I use the above settings for old school thrash, metal, and modern metal & hardcore (I just use different guitars tuned differently).

Don't waste your money on 6L6's, crank the mids & bass, and boost the front end of your 3120 with an overdrive like a tubescreamer or such like, you'll get the darker metal to Ed you're looking for.

(Also, I use 300k volume pots on all my guitars, it gives them a slightly darker tone that I like)

If I turn the gain all the way down I won't get any sound, will I?  I have my amp volume set at 12 o'clock (not the Master volume), mids set at around 10 o'clock, and bass at around 3-4 o'clock, I'm pretty sure.  I'll have to check later for exact settings.

 

[thebutcher85]

Re-read my post, I said the gain on the overdrive pedal was turned all the way down, and the level knob 3/4 of the way up.

The gain knob on the AMP is set to slightly past noon.

 

[thebutcher85]

You need to EQ your amp with your ears and not your eyes. Crank the mids up more; guitar is a midrange instrument, if you've got your mids at 10oclock you won't get a "dark" thick metal tone. Mids are your friend, especially for metal. I crank the mids on all my amps and I always get tons of compliments on how my tone is "thick & Br00tal".

Trust me. Crank the mids, and use an overdrive pedal to boost the front of your amp. That's how it's done...

 

[Torment Leaves Scars]

You need to EQ your amp with your ears and not your eyes. Crank the mids up more; guitar is a midrange instrument, if you've got your mids at 10oclock you won't get a "dark" thick metal tone. Mids are your friend, especially for metal. I crank the mids on all my amps and I always get tons of compliments on how my tone is "thick & Br00tal".

Trust me. Crank the mids, and use an overdrive pedal to boost the front of your amp. That's how it's done...

I'll give that a shot.  :headbang1:

 

[thebutcher85]

You need to EQ your amp with your ears and not your eyes. Crank the mids up more; guitar is a midrange instrument, if you've got your mids at 10oclock you won't get a "dark" thick metal tone. Mids are your friend, especially for metal. I crank the mids on all my amps and I always get tons of compliments on how my tone is "thick & Br00tal".

Trust me. Crank the mids, and use an overdrive pedal to boost the front of your amp. That's how it's done...

I'll give that a shot.  :headbang1:

Also, what setting do you have set on the dampening switch on the back? I like the "tight" setting when I'm playing modern metal with my downtuned guitars, and I like the mid setting with everything else. The 3120 is such a killer amp, I like it waaaaaay better than any of the 5150 or 6505 series!

 

[Torment Leaves Scars]

You need to EQ your amp with your ears and not your eyes. Crank the mids up more; guitar is a midrange instrument, if you've got your mids at 10oclock you won't get a "dark" thick metal tone. Mids are your friend, especially for metal. I crank the mids on all my amps and I always get tons of compliments on how my tone is "thick & Br00tal".

Trust me. Crank the mids, and use an overdrive pedal to boost the front of your amp. That's how it's done...

I'll give that a shot.  :headbang1:

Also, what setting do you have set on the dampening switch on the back? I like the "tight" setting when I'm playing modern metal with my downtuned guitars, and I like the mid setting with everything else. The 3120 is such a killer amp, I like it waaaaaay better than any of the 5150 or 6505 series!

I have it set on the "loudest" setting in the back of the head.  It may be the loosest setting?

I like a lot of resonance with my playing; a bit of a good "thrum."  I'm having trouble achieving that, too.