Can you replace KT66s with EL34s?

[:oilpit:]

Without any major modifications?

Obviously you would need to rebias the amp, but can it be done?

[KSG_Standard]

KT66s are in the same family as 5881/6L6 tubes right? In some Mesa amps, you can swap 6L6 tubes for EL34s with just a flip of a switch.

[AXE®]

I'm not sure I've ever heard of anyone doing it.

 

Eye will keep my eye on this thread.

 

eyeght ?

[djroge1]

Since KT66 is in the family of 6L6 I found this tech article.

 

The following is a quote from the late Ken Fisher - the designer of Train Wreck amps.

 

"Any Fender amp that uses 6L6 power tubes can be converted to use EL34 tues. While the useful life of the EL34 is somewhat shorter than the stock 6L6, the change in tone may make some players feel it is worth spending a little extra for this conversion. After all, beauty is in the ear of the beholder.

 

Be aware that, before performing this mod, you should ascertain that your power transformer's heater supply should be able to handle the extra current draw, as EL34s require 600mA per tube than 6L6s."

 

The rest of the quote goes on to tell how to do the modification. If you have never learned how to discharge filter caps and learned how to safely work inside your amp I would say don't do this on your own.

 

What amp do you have that you are asking about?

[littlekenny]

 

What amp do you have that you are asking about?

 

 

 

its a JTM 45

[matiac]

Don't you have to re bias the amp for any kind of tube swap?

 

Oops, disregard...didn't see that part...just woke up. My bad.

[Murph]

Don't you have to re bias the amp for any kind of tube swap?

 

Oops' date=' disregard...didn't see that part...just woke up. My bad.[/quote']

 

oilpit, go buy Aspen Pittmans "Tube Amp" book.

 

It's quite a study.

 

While he was simply selling tubes when he wrote it, there is a lot of knowledge, and some really cool pictures.

 

I'm not big on biasing amps every time you change tubes. In fact, Mesa amps are fixed. And, having said that, in the '70's and early '80's we just plopped em' in there, and rocked on.

 

I'm a believer that some of those great tones were from amps that were NOT biased correctly.

 

Best to ya.

 

Murph.

[djroge1]

 

oilpit' date=' go buy Aspen Pittmans "Tube Amp" book.

 

It's quite a study.

 

While he was simply selling tubes when he wrote it, there is a lot of knowledge, and some really cool pictures.

 

I'm not big on biasing amps every time you change tubes. In fact, Mesa amps are fixed. And, having said that, in the '70's and early '80's we just plopped em' in there, and rocked on.

 

I'm a believer that some of those great tones were from amps that were NOT biased correctly.

 

Best to ya.

Murph.[/quote']

 

+1 on Pittman's Tube Amp book. That's where the Ken Fisher quote came from I posted earlier. It's not the easiest read, but has a lot of info.