valve question

[bluesfloyd]

hi guys,
if i got a amp that takes el84's i can only use el84's, true or false?????

if i got a amp that takes el34's i could change the valves for 6v6 or 6L6 or kt88 and then even el84's if i use a adptor, true or false?????

all the best, bluesfloyd.

 

[Gone_Shootin]

Re: valve question

It is true that EL84 amps can only use EL84s, But you're a little off on the other question.

EL34, 6V6, 6L6, 6550, KT66, KT77, KT88 and a few others all use an Octal Socket. The issue is with the bias range of any given amp. Generally you're stuck with the tube type that your amp comes with, unless there is an interchangeable tube type, your amp has switch for different tube types (such as the Mesa Rectifier series amps, which are switchable between 6L6 & EL34), your amp has a wide enough bias range to accommodate different tube types (such as the Rhodes Colossus or the Rhodes Gemini), or you mod your amp.

The only adapters I know of are the Yellow Jackets that allow you to run EL84s in an octal socket.

Tubes that are interchangeable are the EL34 & KT77, and the 6550 & KT88. Some people have had success running 6V6s in other applications, but these are only limited instances and generally only work with JJ 6V6s because they are built to withstand a little more voltage (you can read about it at eurotubes.com).

 

[zzmoore]

Re: valve question

Good info above ^^^^^^^
As always, it will depend on the amp...some are designed to be multi tube, some are not.
A 6L6 draws 2x as much heater current as a 6V6.
An EL34 draws 1/2 amp more than a 6L6.
The design of the OT can also be an "issue" when changing tubes.
What amp are you considering.?

 

[bluesfloyd]

Re: valve question

hi guys,
the amp that i am looking at is a reeves custom 50's head, so if i got a amp that took el34's , and because it draws more voltage, its easier to mod to take the 6l6 and 6v6 valves ??????

all the best, bluesfloyd

 

[Edgecrusher]

Re: valve question

hi guys,
the amp that i am looking at is a reeves custom 50's head, so if i got a amp that took el34's , and because it draws more voltage, its easier to mod to take the 6l6 and 6v6 valves ??????

all the best, bluesfloyd

No not necessarily... 6v6's arent going to fly i can tell you that up front. They just flat wont take it. 6L6's MIGHT be within bias range but I would ask the manufacturer to be sure. Judging from the ad copy its not going to be a plug and play deal you will have to change the screen resistors probably.

If your so hot on amps that can take different tubes why not just buy one of those instead of modding an amp?

 

[bluesfloyd]

Re: valve question

hi guys,
i am learning from you guys that you can not just change tube with out some work, in the uk i know of two firms that build custom made amps, i think i will let them build me a amp with a muti tube option,
what must have options would you guys have on a custom built amp, head or combo ????????????

all the best, bluesfloyd

 

[Gone_Shootin]

Re: valve question

Well, my first question would be if they can and/or are willing to build an amp with a wide enough bias range.

But the thing is, if you get an EL34 based amp, you can use KT77s if you want something that's more along the lines of a 6L6 in terms of tone.

 

[Boogie Bill]

Re: valve question

There's a company here in the USA that builds amps like the Uni-Valve, the Bi-Valve and the Flexi-50. All of those amps can use a variety of tubes. The company is called THD, and they build good amps.

Bill

 

[Gone_Shootin]

Re: valve question

There's a company here in the USA that builds amps like the Uni-Valve, the Bi-Valve and the Flexi-50. All of those amps can use a variety of tubes. The company is called THD, and they build good amps.

Bill

Oh duh, I completely forgot about THD. THey make good stuff.

 

[zzmoore]

Re: valve question

Oh duh, I completely forgot about THD. THey make good stuff.

They did.
You can buy a used THD.
Andy Marshall has a price on his head.
There is a reward of 350k to the first guy that turns him over.