EL 84 Pentode Config.

[SINGLEENDED]

EL 84 Pentode configuration.
Sound sweet and nice. Except 2 drawback.
Slow no speed .
Bass sound bloated.
Any suggestion .

[tkifowit]

I have questions.
Do you have a schematic?
Is it se or pp?

[Tube_Dude]

Originally posted by SINGLEENDED
EL 84 Pentode configuration.
Sound sweet and nice. Except 2 drawback.
Slow no speed .
Bass sound bloated.
Any suggestion .

Have you used negative feedback?

[SY]

No NFB = High output Z. High output Z = Big, bloaty bass with speakers not specifically designed for that. And a frequency response that looks like a roller coaster.

[SINGLEENDED]

Found out the problem with the pacing.
Over size supply cable , changed to copper tin type.
Bass still bloated.
Schematic : www. Diyparadise.com/buildel84c.html
It's PP.

[ilimzn]

Why ask questions, if you don't bother to read answers?

[phn]

Scrap the UL. Try connect the screens directly to B+.

[SINGLEENDED]

Still no good.

[dshortt9]

If you have 4,8, and 16 ohm output taps you could use them to apply cathode feedback to the EL84's like Audio Research does. This would tighten up the base.

[phn]

Try triode connect the EL84s. 100 Ohm resistor between screen and anode.

This will reduce gain. But it's a start. If this works you might have to use feedback if you want to run the amp in UL or as pentode. Triodes have internal NFB. Pentodes don't.