ECC81

[Tobruk]

Ecc81

Hi,
I am looking for a schematic about an ECC81 input tube direct coupled to an ECC82 or 6SN7 cathodyne phase splitter for my hombrew push-pull EL 84 amplifier.I thank you in advance.
regards

Franco.-

 

[SY]

You only need to swing 11V or so to drive an EL84 to clipping- why use a phase-splitter with gain and add some extra rolloffs in the bargain? You'd do better, I think, with a voltage amp direct coupled to a split-load. The ECC81 works very, very well in that service.

 

[Tobruk]

Hi,
I think an ECC82 Cathodyne phase splitter has not gain(or very low)
ciao

 

[SY]

Maybe I misunderstand the term "cathodyne." If it's the same thing as a split-load, then do a forum search for the Red Light District amplifier. I used an ECC81 for both the input voltage amp and the split-load- ECC82 is a much inferior tube for that service.

 

[Merlinb]

This is pretty much what you asked for: http://www.freewebs.com/valvewizard/cathodyne.html

 

[Jim McShane]

As Sy said, that's often referred to as a "split-load" phase inverter. And I second his recommendation for the 12AT7, especially if you are using a P-P output stage. A single 12AT7 will provide plenty of gain in the right configuration.

You might look at the "El-Cheapo" front end (on the Decware forum). Of course, Sy's suggestion is good too (I'm sure!), I'm just not nearly as familiar with it.

"El-Cheapo" does not use a cathodyne/split-load PI, but you still might find it very appealing.

 

[EC8010]

Actually, it has more gain...

Although a concertina/cathodyne/split load phase splitter doesn't have gain to an individual output, it has a differential gain of two, so in combination with a typical common cathode input stage it has a gain double that of a phase splitter based on a differential pair.