Current feedback a la Mark Alexander+QRV06 = QRV03

peranders · 5th February 2004, 11:25 AM

http://www5.head-fi.org/forums/showt...threadid=35074

My Alexander headphone amp is slowly coming into life.

The basic concept is the Alexander amp and then I have added my QRV-06 amp as current amplifier.

http://www.analog.com/UploadedFiles/...17334AN211.pdf

Please note that this design is protected by patent which means that my pcb's are not allowed to be used in commercial products, only for personal use. If anyone wonders I have got permission from Analog Devices.

If Christer or someone else would simulate it, I would be very greatful.

sonnya · 5th February 2004, 11:59 AM

Why not take the full step and make a poweramplifier for speakers instead of headphones... Using QRV06?

Just remember to check PSRR (hint)

peranders · 5th February 2004, 12:02 PM

I have thought about making an Power Alexander Amp, but at the moment my Gainclone will to do. I have limited resources, both in time and money so a real good power amp project have to wait.

janneman · 5th February 2004, 12:19 PM

Quote:

Originally posted by peranders
http://www5.head-fi.org/forums/showt...threadid=35074[snip]Please note that this design is protected by patent which means that my pcb's are not allowed to be used in commercial products, only for personal use. If anyone wonders I have got permission from Analog Devices.[snip]

US Patent 5,097,223

Jan Didden

peranders · 5th February 2004, 12:25 PM

Anyone who is interested should also read the very original article published at Audio Engineering Society. Can be download for a small fee from AES.

km · 5th February 2004, 08:59 PM

hi.

indeed a good amplifier.

see; http://www.analog.com/UploadedFiles/...17334AN211.pdf

rgds karsten madsen - www.cadaudio.dk

peranders · 6th February 2004, 05:28 AM

A better scanned AN-211 can be found here:
http://www.diymania.net/pass/project/pic/CF/2646.pdf

Have you seen this?
http://www.diymania.net/pass/project/CF-Power.htm

peranders · 24th March 2004, 01:31 PM

I have tweaked the amp a bit and now it works

It produces a very good sound, both with OPA134 and LT1115.

Sonny, the thing I asked about was just a wild idea which wasn't too good

This "idea" is now removed and the problems are gone.

I suggest that more test the current feedback becuase it's an interesting feedback technology. So many JLH fans couldn't be wrong.

5th February 2004, 11:25 AM	#1
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Current feedback a la Mark Alexander+QRV06 = QRV03 http://www5.head-fi.org/forums/showt...threadid=35074 My Alexander headphone amp is slowly coming into life. The basic concept is the Alexander amp and then I have added my QRV-06 amp as current amplifier. http://www.analog.com/UploadedFiles/...17334AN211.pdf Please note that this design is protected by patent which means that my pcb's are not allowed to be used in commercial products, only for personal use. If anyone wonders I have got permission from Analog Devices. If Christer or someone else would simulate it, I would be very greatful. __________________ /Per-Anders (my first name) or P-A as my friends call me

5th February 2004, 12:02 PM	#3
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	I have thought about making an Power Alexander Amp, but at the moment my Gainclone will to do. I have limited resources, both in time and money so a real good power amp project have to wait. __________________ /Per-Anders (my first name) or P-A as my friends call me

5th February 2004, 12:25 PM	#5
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Anyone who is interested should also read the very original article published at Audio Engineering Society. Can be download for a small fee from AES. __________________ /Per-Anders (my first name) or P-A as my friends call me

6th February 2004, 05:28 AM	#7
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	A better scanned AN-211 can be found here: http://www.diymania.net/pass/project/pic/CF/2646.pdf Have you seen this? http://www.diymania.net/pass/project/CF-Power.htm __________________ /Per-Anders (my first name) or P-A as my friends call me

24th March 2004, 01:31 PM	#8
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	I have tweaked the amp a bit and now it works It produces a very good sound, both with OPA134 and LT1115. Sonny, the thing I asked about was just a wild idea which wasn't too good This "idea" is now removed and the problems are gone. I suggest that more test the current feedback becuase it's an interesting feedback technology. So many JLH fans couldn't be wrong. __________________ /Per-Anders (my first name) or P-A as my friends call me


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5th February 2004, 11:59 AM	#2
sonnya diyAudio Member Join Date: Oct 2001 Location: Denmark	Why not take the full step and make a poweramplifier for speakers instead of headphones... Using QRV06? Just remember to check PSRR (hint)

5th February 2004, 08:59 PM	#6
km diyAudio Member Join Date: May 2001 Location: dk	hi. indeed a good amplifier. see; http://www.analog.com/UploadedFiles/...17334AN211.pdf rgds karsten madsen - www.cadaudio.dk

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