Class-A-Burn: an amp with capacitive feedback divider around MOSFET - Page 2

kenpeter · 23rd August 2009, 08:56 PM

Hours later, this one just isn't explaining itself to me.
I don't even know where to begin? Differential input?

Wavebourn · 23rd August 2009, 09:22 PM

Quote:

Originally Posted by atiq19

Wave,

what is a counter modulated CS? Could i use Nelson Pass over active CS?

I don't know, ask Nelson...

Wavebourn · 23rd August 2009, 09:23 PM

Quote:

Originally Posted by kenpeter

Hours later, this one just isn't explaining itself to me.
I don't even know where to begin? Differential input?

Better start from vacuumless triode output.

destroyer X · 23rd August 2009, 09:50 PM

Will it survive?

Have i miss something?.... 81 watts iddle?... one single transistor back metal plate transfering heat?

regards,

Carlos

Wavebourn · 23rd August 2009, 09:50 PM

Sure, it will survive depending on what kind of output devices you use, and size of heatsink!

One more version, no opamps.

nigelwright7557 · 23rd August 2009, 10:03 PM

Quote:

Originally Posted by Wavebourn

It is a single ended vacuum-less triode amp. As drawn, you can get about 30W on 4 Ohm load, or 60W on 2 Ohm load. With no huge vacuum tubes, no B+ kilovolts, no filament heating. However, one of opamps must be capable of driving 160 Ohm load impedance, and a good heatsink will be needed. Source and emitter resistors mean you may parallel output devices spreading heat dissipation among them, so resistors must have higher resistance, number of devices times. Scott Wurcer gave me last year some samples of AD opamps that I may try in this amp.

I have gone for a SRPP tube front end with MOSFET output transistors.
It gives a valve sound with lots of power at a very reasonable price.

Wavebourn · 23rd August 2009, 10:37 PM

warning!!! Both versions need output coupling capacitor from amp out to speaker! They have 18v dc on outputs!

atiq19 · 23rd August 2009, 10:46 PM

How about capless bipolar psu version?

I am looking for a anti clip ckt matching your buffer.

Wavebourn · 24th August 2009, 01:47 AM

Quote:

Originally Posted by atiq19

How about capless bipolar psu version?

For bipolar psu it will be more complex.

By the way, some gate stoppers will be needed, depending on MOSFETs used.

Lumba Ogir · 24th August 2009, 02:38 AM

Wavebourn,
tell me very confidentially, why extend the already huge and extremely harmful internal capacitances? What are they supposed to divide?

23rd August 2009, 09:50 PM	#14
destroyer X diyAudio Member Join Date: Feb 2004 Location: Recife - Brasil Northeast	All that power... continuous into a single solid state triode Wavy? Will it survive? Have i miss something?.... 81 watts iddle?... one single transistor back metal plate transfering heat? regards, Carlos __________________ Audiophoolery; http://www.youtube.com/watch?v=m7ERMu825m4; Dx Super Etching; http://www.youtube.com/watch?v=WED3Bvmxepk

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23rd August 2009, 08:56 PM	#11
kenpeter diyAudio Member Join Date: Nov 2007 Location: Dallas	Hours later, this one just isn't explaining itself to me. I don't even know where to begin? Differential input?

23rd August 2009, 09:50 PM	#15
Wavebourn diyAudio Member Join Date: Sep 2006 Location: Pleasant Hill, CA	Sure, it will survive depending on what kind of output devices you use, and size of heatsink! One more version, no opamps.

23rd August 2009, 10:37 PM	#17
Wavebourn diyAudio Member Join Date: Sep 2006 Location: Pleasant Hill, CA	warning!!! Both versions need output coupling capacitor from amp out to speaker! They have 18v dc on outputs!

23rd August 2009, 10:46 PM	#18
atiq19 diyAudio Member Join Date: Jun 2007	How about capless bipolar psu version? I am looking for a anti clip ckt matching your buffer.

24th August 2009, 02:38 AM	#20
Lumba Ogir Banned Join Date: Apr 2005 Location: Stockholm	Wavebourn, tell me very confidentially, why extend the already huge and extremely harmful internal capacitances? What are they supposed to divide?