excellent phonostage schematic

lt cdr data · 2nd October 2010, 01:55 PM

I would llike to know what the 5532 in the nfb loop is doing?

jacco vermeulen · 2nd October 2010, 02:58 PM

Biasing Op-Amps into Class A

lt cdr data · 2nd October 2010, 03:15 PM

ftp://ftp.analog.com/pub/www/library.../.../AN107.pdf

analog_sa · 2nd October 2010, 04:32 PM

Quote:

Originally Posted by lt cdr data

I would llike to know what the 5532 in the nfb loop is doing?

Nothing that makes sense to me. Badly drawn circuit?

benb · 2nd October 2010, 06:11 PM

It's definitely a badly drawn schematic, but by painfully staring at it long enough I see the circuit. Both the (vertical) 51r's are next to LM334 current sources on the outputs of the 5532's, for forced class A operation, as the link in post #2 explains.

The second 5532 within the feedback loop does appear to be for the purpose described in Analog's AN107 app note. The LF411 is of course a servo to zero the output offset.

The link in post #3 is broken. The correct and unmutilated URL for the Analog Devices AN107 is (right click and copy the LINK, not the text!):
ftp://ftp.analog.com/pub/www/library...tion/AN107.pdf

vAD · 07:32 PM

It horror

LAJ · 2nd October 2010, 07:43 PM

There is a good op amp phono preamp (or tape preamp depending on component selection) using the LM387 in the National Semiconductor Audio/ Radio Handbook.

2nd October 2010, 07:29 PM	#6
vAD diyAudio Member Join Date: Apr 2005 Location: Russia	It horror Last edited by vAD; 2nd October 2010 at 07:32 PM.

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

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
freaky new phonostage	Vinylsavor	Tubes / Valves	35	30th November 2010 07:30 AM
Phonostage tuning	Smoke Screen	Analogue Source	8	29th December 2009 08:38 PM
Looking for 12AT7/ECC81 phonostage schematic	alexg	Tubes / Valves	1	21st August 2008 03:13 PM
phonostage with 150VDC B+	alexg	Tubes / Valves	9	18th August 2007 01:13 AM

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

2nd October 2010, 02:58 PM	#2
jacco vermeulen diyAudio Member Join Date: Oct 2004 Location: At the sea front, just under Rotterdam	Biasing Op-Amps into Class A __________________ Looks like Sponge Bob has killed another thread.

2nd October 2010, 03:15 PM	#3
lt cdr data diyAudio Member Join Date: Dec 2003 Location: earth	ftp://ftp.analog.com/pub/www/library.../.../AN107.pdf

2nd October 2010, 06:11 PM	#5
benb diyAudio Member Join Date: Apr 2010	It's definitely a badly drawn schematic, but by painfully staring at it long enough I see the circuit. Both the (vertical) 51r's are next to LM334 current sources on the outputs of the 5532's, for forced class A operation, as the link in post #2 explains. The second 5532 within the feedback loop does appear to be for the purpose described in Analog's AN107 app note. The LF411 is of course a servo to zero the output offset. The link in post #3 is broken. The correct and unmutilated URL for the Analog Devices AN107 is (right click and copy the LINK, not the text!): ftp://ftp.analog.com/pub/www/library...tion/AN107.pdf

2nd October 2010, 07:43 PM	#7
LAJ diyAudio Member Join Date: Mar 2008 Location: Atlanta Ga. USA	There is a good op amp phono preamp (or tape preamp depending on component selection) using the LM387 in the National Semiconductor Audio/ Radio Handbook.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)