Op amp swapping - Page 4 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

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 27th October 2010, 06:14 AM   #31
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Looks like the 4562's are bad or counterfeits to me. Where did you get them from ? The distortion looks like crossover problems in the output stage... if they are counterfeit they could be anything, comparators even and not opamps at all.
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 27th October 2010, 07:08 AM   #32
liquias is offline liquias  Israel
diyAudio Member
 
Join Date: Jul 2004
Location: israel haifa
It is possible. I have no choice but to buy some of my components from ebay.
This batch was bought on ebay. The problem is I have no way to get some lm4562s, but from ebay again...
How come everything looks fine when I raise R2 and R1's value ?
  Reply With Quote
Old 27th October 2010, 07:23 AM   #33
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Raising the value of the resistors eases the load on the output stage... which should be irrelevant here... but as it's not it makes me suspect these are not even opamps as such, or perhaps some device with an open ended output stage.

Out of interest try adding a resistor of say 1k from the opamp output to the positive rail, and then try same to negative rail. Does the distortion go ?
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 27th October 2010, 07:24 AM   #34
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
I found this,
Fake LM4562? - Head-Fi.org Community
__________________
-------------------------------------------------------
Installing and using LTspice. From beginner to advanced.
  Reply With Quote
Old 28th October 2010, 09:19 PM   #35
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
I got some as samples from NatSemi. I wouldn't trust to buy them from China... I think there are other legitimate shops that would ship to Israel - Farnell?
  Reply With Quote
Old 28th October 2010, 10:25 PM   #36
diyAudio Member
 
theAnonymous1's Avatar
 
Join Date: Feb 2004
Location: Anonymityville
I gifted him a couple pieces of genuine LM4562. Put them in the mail yesterday.
  Reply With Quote
Old 29th October 2010, 07:06 AM   #37
liquias is offline liquias  Israel
diyAudio Member
 
Join Date: Jul 2004
Location: israel haifa
Guys, thank you all ! so much !
It does look like I've been had. I have been hearing about fake parts for quite some time now (mostly in DIY-Audio), but e-bay is and unfortunately will be one of my sources for electronic components, since I live in Israel. There are very little shops around here that carry stock components, and I'm talking nation wide (well, a very small nation ).

Farnell do ship here, but they use local dealers that use to be electronic components shops (Now they only serve as extensions of Farnell). The bad news is that recently they started charging a not so small fee for the shipment if the total price is less than 100US$. This makes me wait for 6 months or so (to gather enough components I need...) before I order anything from Farnell. And I still use Farnell quite allot (mostly work related) (two weeks ago I got a shipment of components from them, long time till I'll be able to order again...)
Farnell is one of the only shops that ship to Israel. Digikey also ships here, but again they ask for 40US$ only for shipment. And there aren't any others as far as I know.

I use e-bay, since I can order allot of things I need, most of the time price is good enough, and I pay for each item individually. Plus, I really don't have a choice some times. This is the first time I have encountered counterfeits. I guess this is inevitable, but it's still not very common.

I do not know where I could find LM4562s other than e-bay at the moment. In-fact when I got theAnonymous1's offer for help, I was looking around in e-bay pages of4562's wondering how I can tell the good ones (If there are any) from the fake ones. I wonder if the seller himself knows about the parts being fake.

Again, THANK YOU ALL, for offering your knowledge, your time, and your components .
I am proud of being a part of this group, and I hope that in some day, I'll be able to return the favor.
  Reply With Quote
Old 29th October 2010, 07:45 AM   #38
liquias is offline liquias  Israel
diyAudio Member
 
Join Date: Jul 2004
Location: israel haifa
@Mooly,
found this :
Replace NE5532AN
Now I know why you suggested the 40 Ohm resistor on the outputs of the op amps ....
  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
Swapping Threshold S & SA frontboards. RobertS61 Pass Labs 8 29th April 2010 09:58 PM
Swapping in transformer? jackfish Power Supplies 9 29th March 2010 01:01 AM
swapping op-amps in a vestax pmc-55 sr126 Chip Amps 4 26th June 2008 04:23 PM
Swapping an A/C Adapter FrankRoss Power Supplies 2 11th May 2006 01:16 AM
Swapping tda2030b with ???? texus Chip Amps 0 18th March 2005 07:28 AM


New To Site? Need Help?

All times are GMT. The time now is 03:43 AM.


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