CA 640P opamp advice please

[ben556473]

Hello, could I ask a very specific question? I have been modifying my Cambridge Audio Azur 640P for a while now, if you are interested you can go to here and have a look
http://www.vinylengine.com/phpBB2/al...hp?pic_id=4820
I now intend to change the opamps but have no knowledge or experience of fiddling with these. The originals are N5532 in both the passive RIAA equalisation and amplification stages of the unit. For the greatest improvement in sound quality could I fit a pair of OPA637 on a Browndog adapter board to replace each of the originals? All help and suggestions are very much appreciated, you can read what I've done so far in the thread here if you fancy
http://www.vinylengine.com/phpBB2/vi...er=asc&start=0
Thanks for your help, Ben.

[ben556473]

Hello, have I asked this question in the wrong part of this forum or is it too specific? Any help would be greatly appreciated.

[ben556473]

Well I fitted four OPA637AU-NP opamps in place of the two NE5532P originals and the results are great, better sound in every way. I used the Browndog adapters (dual mono surface mount to single through hole ) which are very nicely made little things. Hope this is of help if anyone who is considering doing a similar thing. I would say thanks for the advice but as I did not even get any recognition of this post I shall not bother again. Ben.

[kevinkr]

Hi Ben,
You posted this in the wrong place, this is the chipamp forum - land of LM3886 power amplifiers and other similar subjects, you should have posted this in the analog(ue) forum instead.

Good to hear it worked out though. You might also want to take a look at the LM4562 from National. I used them in a dac upgrade and I was surprised at how good they were - their noise floor is ideal for phono stage use. (I'm a tube/valve guy so I hardly ever look at this particular part of the forum otherwise I would have answered you sooner.)

[Kinnja]

Originally posted by ben556473
Hello, have I asked this question in the wrong part of this forum or is it too specific? Any help would be greatly appreciated.

I wouldn't say that you posted in the wrong forum. I don't know if there is a firm definition for Chip Amp, but it seems that most of them are made from op amps. I believe the LM3875 and the LM3886 are both op amps designed for audio. Either that or they have a lot in common with op amps.

Here is a link to a DIY Op Amp article that might interest you:
http://www.passdiy.com/pdf/diyopamp.pdf

PassDIY is a very informative web site.

You might also try the Solid State forum.

[kevinkr]

Originally posted by Kinnja


I wouldn't say that you posted in the wrong forum. I don't know if there is a firm definition for Chip Amp, but it seems that most of them are made from op amps. I believe the LM3875 and the LM3886 are both op amps designed for audio. Either that or they have a lot in common with op amps.

Here is a link to a DIY Op Amp article that might interest you:
http://www.passdiy.com/pdf/diyopamp.pdf

PassDIY is a very informative web site.

You might also try the Solid State forum.

"Chip Amp" actually has a pretty specific meaning which is basically any power amplifier project based on an analog power amplifier on a chip. One example is the ubiquitous LM3886 and many of the other high power National Overture series monolithic power amplifier ics.. SGS makes some as well. As noted all of these are power op-amps..

Phono stage stuff generally lives in the analog(ue) area of the forum if solid state or the solid state forum or if tubed in the tubes forum.