modifications to compact EL84 amp

[Joel]

Re: CONSERVATIVES.

If you value awesome dynamic range and deep,solid bass...follow my lead.

Be careful Frank - you're implying that frequency response of an amplifier is determined by power supply capacitance - which is not true really.

There is no need for larger than a 100uF cap in any tube amp.

 

[fdegrove]

I KNOW WHAT I'M DOING.

Hi,

Be careful Frank - you're implying that frequency response of an amplifier is determined by power supply capacitance - which is not true really.

It's not frequency response as it is statically measured but sustained bass tones from a complex musical signal.
AKA perceived dynamic range, AKA headroom.

This is especially true for Class AB amps (most oldies are) and won't do any harm to a Class A amp either.

Think dynamic,think music,

 

[planet10]

Re: elegance

]perhaps this has still some more elegance:

I have something similar in the queue using an Edcor (budget) tranny as phase splitter on the input (don't know how much DC it will take) and a pr of drivers after into EL84s (or a pr of ECL 82, or 86). Iron from an old Normende.

dave

 

[Brett]

Don't want to sound negative but i've tried liberating EL84 pentode amps from negative feedback and the results have been quite lo-fi. Anyone been luckier?

cheers

peter

Agreed. The EL84, which can be a really sweet tube is best in NFB UL applications like the ST35/SCA35 or even better as a class A PP triode, if you can deal with the 3W it puts out.

 

[Brett]

Re: elegance

perhaps this has still some more elegance:

Jaap,
Phase split before the driver and run the driver PP. Works much better to my ears.

There's been a long thread here about a similar circuit in the past (Ralph poweramp). Also check the writings of Lynn Olson at his site ( www.aloha-audio.com ) as well as the archives at audioasylum under his name, and Garry Dahl (gdahl) who was the designer of the Ralph poweramp. There is tons of valuable info there, as they are both very experienced, and measure everything as well as listen to tune the circuits.

 

[Jaap]

thanks for the suggestions