BPA200, replacing LF412ACN with? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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
Reply
 
Thread Tools Search this Thread
Old 17th November 2006, 06:57 AM   #1
CJ900RR is offline CJ900RR  Sweden
diyAudio Member
 
Join Date: Jan 2006
Default BPA200, replacing LF412ACN with?

Thinking of constructing a pcb based on the BPA200 in Nationals AN1192.

My simple question is, can I replace the LF412ACN with LM4562 straight forward, or do I have to re-calculate the values on other components to?

Best regards, Calle...
  Reply With Quote
Old 20th November 2006, 01:00 PM   #2
diyAudio Member
 
tlmadsen's Avatar
 
Join Date: Aug 2003
Location: Roskilde - The vikingships
HI Calle

Normaly you should be able to replace LF413 with all most any other DUAL op-amp, but why would you. ??
It is part of the DC-servo, so the only real important parameter is its offset. Something like the AD712 (I think it is called) might be better in that respect.

Your DC-servo will not sound "better" by putting a fancy Dual op-amp into it.

I have no problem using a DC-servo (see some of my other replys), but people that don't like them are normally against the hole "topology" more than a single component.

Have fun
  Reply With Quote
Old 20th November 2006, 01:20 PM   #3
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
The servo opamp will feed back audio signals up to 500 Hz to 1 kHz. So it must be good in those frequenies which most decent opamps are. Over 100 Hz a very small part of the audio signal goes through the servo. As Thomas says almost any opamp will fit. Personally I chosen an AN8620 as a buffer + servo and for the servo part it's massive overkill but it's nice with 80 uV offset! You can see my implementaion of AN-1192 at my homepage.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 20th November 2006, 01:20 PM   #4
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
The servo opamp will feed back audio signals up to 500 Hz to 1 kHz. So it must be good in those frequenies which most decent opamps are. Over 100 Hz a very small part of the audio signal goes through the servo. As Thomas says almost any opamp will fit. Personally I chosen an AD8620 (or OPA2134) as a buffer + servo and for the servo part it's massive overkill but it's nice with 80 uV offset! You can see my implementaion of AN-1192 at my homepage.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 20th November 2006, 07:30 PM   #5
CJ900RR is offline CJ900RR  Sweden
diyAudio Member
 
Join Date: Jan 2006
Thank you for your answer. That was what I thougt. And today I found some LF411 and LF412 stuffed away at my work. But they where labeled only CN, not ACN. But what I can see from the datasheet its only V-rating that difference from the ACN-version... I will try them first.

But I have a new question. How do I do with the mute-part of the LM886. Do i need mute-resistors and cap's for every LM3886, or do I need only one to mute them all?

Best regards, Calle...
  Reply With Quote
Old 20th November 2006, 08:00 PM   #6
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
The mute resistor is very important. No resistor = MUTE.

10k is a normal value but I did chose 33k + 100 uF just because I wanted a longer delay _with_ a 100 uF cap. If you don't want the delay, just omit the capacitor but it may be a good idea to have it since you have a DC servo which may create a small startup transient. Please check the datasheet and the diagram over this mute resistor. You should have more than 0.5 mA from that pin.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 20th November 2006, 09:03 PM   #7
diyAudio Member
 
BrianDonegan's Avatar
 
Join Date: Dec 2004
Location: TPA HQ
Interesting post on the mute resistor:

http://www.diyaudio.com/forums/showt...710#post845710

Try a 4k7.

Also, we are using the LF411CN with great results.
__________________
Twisted Pear Audio
  Reply With Quote
Old 21st November 2006, 03:16 PM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Notice also my comment there about the measurements.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
scratch BPA200 pcb lay out digi01 Chip Amps 63 21st December 2007 07:51 PM
Bpa200 Lm3886 zlast Chip Amps 9 7th July 2007 04:27 AM
Bpa200 Opa549 Sub Amp Gcollier Chip Amps 8 2nd October 2006 11:58 PM
Bpa200 enter Chip Amps 2 3rd January 2006 08:16 PM
My BPA200 PCB Dxvideo Chip Amps 14 11th December 2003 07:25 AM


New To Site? Need Help?

All times are GMT. The time now is 08:31 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2