KT77's in a Peavey Classic 20?

[zonzin]

Can the EL84's in a Peavey Classic 20 be replaced GL KT77's?


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[Helmholtz]

Completely different tube and tube base/socket.

The KT77 can replace an EL34, though.

[zonzin]

Completely different tube and tube base/socket.

The KT77 can replace an EL34, though.

Copy that. Will a KT88 swap in?

[glebert]

No, same problem. There really isn't much you can swap in for a EL84, what are you looking to get from the change?

There are some adapters to put 6V6 into an EL-84 socket. I have no idea if that would be a good idea with a Classic 20.

[Helmholtz]

Copy that. Will a KT88 swap in?

No, the KT88 is even bigger than the KT77 and has an octal base as well.

The EL84 is a small power tube using a noval base like preamp tubes.

Just google for datasheets, pictures and dimensions.

[zonzin]

Thanks folks. Questions answered.

[nevetslab]

Can the EL84's in a Peavey Classic 20 be replaced GL KT77's?


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You CAN use a 7189 Tube as a substitute for the EL84. It has higher plate voltage capacity. Same Pin-out, though the 7189A makes use of Pin 1 in along with Pin 2 as the input grid. Pni 1 isn't used on the EL84.

7189.pdf
el84-philips1969.pdf

[Chuck H]

Well it sounds like zonzin doesn't want to be forthcoming with the end goal with a simple "Thanks folks. Questions answered."

But if I may speculate...

It seems to me the goal is either a tonal change or, more likely, more power. Which is another matter. So I'll just note here that swapping a higher power tube into a given amp will not typically result in more power. Since tubes only reflect the circuit function, not the other way around. So even with the 7189 tube you would not get more power. Just a more robust tube doing the same level of work.

And zonzin didn't ask, but... If you want more volume your best bet would be to swap the stock Peavey speaker for something very efficient. If you can find a speaker with 3dB higher efficiency the increase in volume is equal to doubling the power out of the amp. I don't know much about current Peavey speakers but I think this is possible.

[Chuck H]

FWIW I have had this experience with a Peavey "classic" series amp. A 2x12 Classic 50. The customer wanted to tame the ice pickey HF and just overall balance of tonal aspects. I had a couple of pairs of speakers on hand and the ones I chose were the Eminence Private Jacks. These are typically used in (and recommended for) closed back cabinets though within wattage limits there's some wiggle room. The improvement in tone was the difference between a store bought tomato and a garden ripe tomato in flavor. The volume increase was also obvious and welcome. With no other mods I can honestly say that a stock Classic 50 with a pair of Eminence Private Jacks loaded into it is an amp I could happily use for gigging. I've mentioned it here before and I can't say it enough. A pairing that's greater than the sum of it's parts and way more tone and feel than any "affordable" commercial amp has rights to.