First tube amp.... el84 ? 6L6? Help

I just bought a Peavy classic 50 4x 10. Manual says it has (4) el84 and
(3) 12ax7.
Its an older model. Are EL 84's interchangeable with 6L6's or El 84's or must I replace them with manual specs ????

Hi

EL84's are NOT interchangeable with 6L6s. For one thing, they take a completely different socket. For another, an EL84 has 9 pins, a 6L6 has eight.

You can put 6L6s in your amp if you:

- take out the EL84 sockets
- drill really big holes in the chassis
- put in octal sockets
- change a lot of the circuitry
- replace the output transformer
- possibly replace the power transformer or add a filament tranny

All this adds up to Big Bucks.


but it would make more sense to just buy a 6L6 amp. Or just stick with EL84s. The Classic 50 is a great amp, be happy with it. (as it is)

steven

The Peavey Classic 50 uses only EL84's, which are smaller tubes than the 6L6's. Use only EL84's.

You do have some latitude to switch the 12AX7's with other types though. For a lower gain and sweeter clean tone, try a 5751, 12AT7 or 12AY7 in the V1 position nearest the input jacks. 5751 is closest in gain to your existing 12AX7....the 12AY7 is the lowest gain tube....my favorite.

Great advice. Very helpful.
Thanks so much!

Am I to understand that I can replace one ( not all) of the 12ax7 's with tube that doesnt match? Do all the tubes need to match I guess is really my question.

Preamp tubes do not need to be matched... On preamp tubes, sometimes the Phase inverter tube needs to be a "stouter" tube, but other than that 12ax7's are not near as picky as power tubes..... Heck, some preamp tubes will last 2-3 (or more) decades! You can also swap out 12ax7 tubes with just about any 12a?7 tube and even a 5751.

Confused yet?

Almost.....
Please explain "Inverter tube" and "stouter" as it refers to tubes.
Also, Any input on brand names ??

"Confusion is just a state of mind"

BUt don't despair... you can interchange the EL84s with 6BQ5s any time!

heheheheehhehehehehehehehehehe

Almost.....
Please explain "Inverter tube" and "stouter" as it refers to tubes.
Also, Any input on brand names ??

"Confusion is just a state of mind"

BUt don't despair... you can interchange the EL84s with 6BQ5s any time!

heheheheehhehehehehehehehehehe


They are the same No??

They are the same???? Yes

Looks like you might be in over your head right now...... If you are looking to replace your tubes, replace the 4 EL84's with the same type.

The phase inverter tube is usually the small 9-pin "preamp" tube closest to those EL84 power tubes. It's job is to supply matched voltage to the power tubes, that's why someone posted that a "stouter" tube might be desirable. Stouter meaning higher gain.

Common preamp tubes are from high to low gain: 12AX7, 5751, 12AT7,12AY7,12AU7

Higher gain is not always the best.....sometimes you need a lower gain tube because it doesn't sound so aggressive and in-your-face. Beyond just gain, the tubes have other specific uses.

12AT7's and 12AU7's are used in reverb driver applications because they are built to handle the higher voltages in those circuits.

12AX7's have low noise variants called 7025's.

Most amps nowadays seem to use the 12AX7's because the high gain of this tube allows some good crunch when you crank up your amp. However I personally am not a fan of that high gain thing, especially when the amp starts crunching out at about 5 on the volume knob.

Putting in a lower gain 12AY7 or 12AT7 gives you a lot more control over the volume knobs travel. In fact, you can turn up much higher and stay clean. You might sacrifice a bit of crunch, but you'll gain control over your amp through the use of your guitar volume knob.....which is how I like to play.

Thank you. Thats exactly the info I was looking for.
You teach a great "Tube" class.

i always use a "balanced' 12AX7 in the Phase Inverter as well.

i always use a "balanced' 12AX7 in the Phase Inverter as well.


That's what I was meaning by "Stouter"..... If you use a lesser quality tube in the phase inverter position, it can get a little noisy sometimes.

As for name brands, most everybody will give you a different answer.... I personally like JJ's for the el84's, and as for preamps tubes....... I really like the new production of EH tubes. The JJ's aren't bad either. A lot of people will say NOS are best (new old stock), but you also pay 3-4 (or more) times as much per tube, and for the price there are many current production 12ax7 tubes that are really good.

FYI: Dr Z uses Groove Tubes el84's in his new amp, I like those as well.

If the amp is behaving and sounding good right now, do yourself a favor and don't sweat it! Just hang out here and let the information absorb, and you'll have a good idea what to do when necessary. I wouldn't even swap tubes while you get to know your new amp. :grin:

Welcome to the TDPRI!

- Scott

The Quote Function Won't Work Right Now.

"EL84's are NOT interchangeable with 6L6s. For one thing, they take a completely different socket. For another, an EL84 has 9 pins, a 6L6 has eight.

You can put 6L6s in your amp if you:

- take out the EL84 sockets
- drill really big holes in the chassis
- put in octal sockets
- change a lot of the circuitry
- replace the output transformer
- possibly replace the power transformer or add a filament tranny

All this adds up to Big Bucks.


but it would make more sense to just buy a 6L6 amp. Or just stick with EL84s. The Classic 50 is a great amp, be happy with it. (as it is)"

steven

My Dad recently did this for a guy. If I remember correctly the customer was fussy about which output transformer was used. I've heard this customer play he's good. I heard him with his old amp and I've heard him with his new one. He sounded the same. If your after a certain tone, sound when you find it you will set all your amps to produce that tone, sound.

Advice, get your pedals dialed in and you can play through anything and get THE SOUND you want.

I know professionals who don't use on stage amps. They use ear bud monitors and rack mounted stuff. You can put your whole system in a rack the size of a fridge. I got off on a tangent.

Substituting 6L6's for EL84's sounds like what a friend did to his Ford 8N. He converted it to a 12 volt system from a 6 volt. Now he's the only one who can start it. :shock: Becareful and don't break something.

Bandit wrote: "My Dad recently did this for a guy. If I remember correctly the customer was fussy about which output transformer was used. I've heard this customer play he's good. I heard him with his old amp and I've heard him with his new one. He sounded the same. If your after a certain tone, sound when you find it you will set all your amps to produce that tone, sound."

THis is proof of a few things.
1)The circuit determines much of what goes on with the sonics...regardless of the power tubes used.
2)IF the player uses the same set of ears and fingers, the player will utilize whatever equipment they have to achieve much the same sonics...regardless.
3)Chasing the pot of gold at the end of the rainbow only causes those little elves to laugh their a$$e$ off.
But, hey, there may be that there was some small change in the amp that the player liked....and that is not perceptible to others. IF so, I am sure that the player is happy.

I have that amp and the many tube changes I did I found it made very little difference. It still sounded very much like the same amp. I think I liked the 5751 abit more and the 5751 a bit less but thats being very picky. ITs a very good amp that sounds great even with cheap tubes (as designed). Killer clean and good overdrive tone that smoothes out great with a tube screamer.

EL84's only, man.

If you get an amp with 6L6's, you could get those Yellowjacket adapters that allow you to plug el84's into the octal sockets.

http://www.thdelectronics.com/pdf/yj.pdf

I think for around $100US you can get a pair of adapters with tubes included. You have to look around online, as THD does not sell them directly. That being said, I have never tried them out. I'd rather just have an amp with el84s in it full time. I made a Champ clone that contains an extra socket that allows you to pull the 6V6 and put in an el84 instead.

EL84 wins out every time.