Schade84 - Page 4

kenpeter · 17th April 2009, 03:31 AM

And cathode feedback can produce a Schading effect.
Stand the tube on one of your secondary windings.

Some PushPull will have the 4ohm Grounded. Cause
the common and 16 are actually tied to the cathodes.
Same thing, only different....

Any variance at Cathode looks just like a variance in
the grid, only inverted....

revintage · 17th April 2009, 07:11 AM

Hej Vega65!

The detailed explanation is all in the Schade-paper Svein linked to.

Sveins circuit has a few tiny faults and will not work properly IRL.

If you instead check the 2nd circuit in my post after his I have corrected them to a working one with active components relevant to this thread.

Can mail you the *.asc file together with tube models to play around with. This way you will learn by simming

.

Bandersnatch · 17th April 2009, 10:26 AM

Quote:

Originally posted by pmillett
Yet another way of getting P-G feedback...

http://www.pmillett.com/uc300b.htm

hey-Hey!!!,
Nice...TX-coupled E-Linear...

I will be sure to find that aX issue when you've got your article in it.
cheers,
Douglas

revintage · 12th May 2009, 11:29 AM

Heja Svein,
You where on the right track when you exactly followed Schades original circuit. This is the way to go!

With quite a few tricks and tweaks this will make a nice amp, and why not make it MOSFET?

The 6AQ5 will have less than 1% THD with triode characteristics at 4W. The MOSFET 10W below 1% with 18V B+!

Michael Koster · 12th May 2009, 05:46 PM

Lars,

Are the caps in parallel with the feedback resistors for balancing the
reverse transfer capacitance of the output element?

revintage · 12th May 2009, 06:12 PM

Had to add them by trial-and-error to tame a HF-peak. Have to see what happens IRL when we build them up. The MOS version has now a -3dB at over 100kHz. Can not explain the spiced good result

.

Have to order the Hammond 193Us to find out.

12th May 2009, 06:12 PM	#36
revintage diyAudio Member Join Date: May 2007	Had to add them by trial-and-error to tame a HF-peak. Have to see what happens IRL when we build them up. The MOS version has now a -3dB at over 100kHz. Can not explain the spiced good result. Have to order the Hammond 193Us to find out.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

17th April 2009, 03:31 AM	#31
kenpeter diyAudio Member Join Date: Nov 2007 Location: Dallas	And cathode feedback can produce a Schading effect. Stand the tube on one of your secondary windings. Some PushPull will have the 4ohm Grounded. Cause the common and 16 are actually tied to the cathodes. Same thing, only different.... Any variance at Cathode looks just like a variance in the grid, only inverted....

17th April 2009, 07:11 AM	#32
revintage diyAudio Member Join Date: May 2007	Hej Vega65! The detailed explanation is all in the Schade-paper Svein linked to. Sveins circuit has a few tiny faults and will not work properly IRL. If you instead check the 2nd circuit in my post after his I have corrected them to a working one with active components relevant to this thread. Can mail you the *.asc file together with tube models to play around with. This way you will learn by simming .

12th May 2009, 05:46 PM	#35
Michael Koster diyAudio Member Join Date: Jan 2008 Location: Eureka, CA	Lars, Are the caps in parallel with the feedback resistors for balancing the reverse transfer capacitance of the output element?