A Good Pentode Push-Pull Amplifier

Assorted info that will be of use, spec sheets, docs etc. Non informational postings will be removed.
Post Reply
Cressy Snr
Oooo, Roberts Radio's sound nice
Posts: 7483
Joined: Wed May 30, 2007 12:25 am
Location: Away with the Faeries

A Good Pentode Push-Pull Amplifier

Post by Cressy Snr » Sun Feb 21, 2016 3:18 pm

Here are the schematics for the final version of the pentode push pull amp I have been developing over the past few years.
A long story but the results are rather good.

Audio Circuit:
Image

Power Supplies:
Image
Oh it's a doobidee doo, yes it's a doobidee doo, I mean a doobie doobie doobie doobie doobidee doo.

Cressy Snr
Oooo, Roberts Radio's sound nice
Posts: 7483
Joined: Wed May 30, 2007 12:25 am
Location: Away with the Faeries

Re: A Good Pentode Push-Pull Amplifier

Post by Cressy Snr » Fri Feb 26, 2016 7:42 pm

Just a small comment on the power supply. It is not essential to emloy Morgan Jones Statistical Regulators on the power stage screen grids. Simple Zener string shunts could be used for very little a drop-off in performance, and I have changed the schematic to reflect this.
The excellent noise performance of the statistical reg gives the biggest performance boost when employed to regulate the input stage pentode screens. Statistical regulation of the output stage screens could be a teensy bit overkill; depends how far you want to take things. I'm not saying don't use them, but......

A nice little series tube regulator is a good way to keep the output stage screens locked down, but I haven't tried that on this project. Something like a 6EM7 dissimilar triode with the hi-mu unit as the error amp, might be good.
Last edited by Cressy Snr on Sun Mar 06, 2016 10:37 am, edited 1 time in total.
Oh it's a doobidee doo, yes it's a doobidee doo, I mean a doobie doobie doobie doobie doobidee doo.

User avatar
jack
Shed dweller
Posts: 2672
Joined: Wed Dec 29, 2010 8:58 pm
Location: Somewhere that's quite nice & temperate with, astonishingly, a possibility of rain.
Contact:

Re: A Good Pentode Push-Pull Amplifier

Post by jack » Sun Feb 28, 2016 1:56 pm

I would agree with you on that. They are best in small-signal environments e.g. front-end, pre-amps and line stages... places where the s/n ratio is critical.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest