Opamps distortion test

[roibm]

In my quest for finding a replacement for the NJM2068 opamp, I've found an interesting page that compares some of them.

http://fnt-www.ss.titech.ac.jp/~haji...rtion/opa.html

It is in japanese but, http://world.altavista.com/ works good enough. And the again, there are quite some charts. The opamps are a bit old, but many devices still uses them, so I thought this could be helpful.

On the same site there is also a caps distorsion test:
http://fnt-www.ss.titech.ac.jp/~haji...cap/index.html
including black gate, os-con, siemens.

PS: If you have a sugestion regarding my NJM2068 related quest, don't be shy

[johnferrier]

Here is another site: http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm


JF

[roibm]

nice site, thanks

[fmak]

[QUOTE]Originally posted by johnferrier
[B]Here is another site: http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm


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Unfortunately he concludes that one of the worst sounding opamps (5532) is the best overall!

If you hear a 1-D mretallic sound from pro gear, it is likely that NE5532s are used. Samne with Japanese equipment using 5534 DD which is even 'better'.

[Christer]

I remember PMA posting a link to some distorsion graphs for
a lot of op amps, but chekcing his home page and searching
the forum, I couldn't find it right now. Anybpdy who remembers
it? Pavel, are you reading this?

[macaque]

Originally posted by fmak
Unfortunately he concludes that one of the worst sounding opamps (5532) is the best overall!

If you hear a 1-D mretallic sound from pro gear, it is likely that NE5532s are used. Samne with Japanese equipment using 5534 DD which is even 'better'. [/B]

I know the NE5532 has a bad rap amongst DIYers. Has anyone else here tried the Cirrus Logic CS4398 evaluation board? The default output stage for the unbalanced outputs of the board uses a Philips branded surface mount NE5532 for each channel (wasting one of the dual opamps in each chip) as a 2nd order butterworth filter with a 48KHz 3dB point. I am powering the rails for this with batteries.

The sound coming out of this is very 3D and very warm (almost tube like). There is plenty of low level detail but absolutely no sibliance - and I am using silver/copper cables.

Everyone here talks about how it sounds 1D and harsh but this is the opposite experience as to how it sounds on this board. The balanced output uses LT1128 but I haven'd tried the balanced outputs yet.

[fmak]

The sound coming out of this is very 3D and very warm (almost tube like). There is plenty of low level detail but absolutely no sibliance - and I am using silver/copper cables.

Everyone here talks about how it sounds 1D and harsh but this is the opposite experience as to how it sounds on this board.
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You may find that the coupling caps may have something to do with it.

[roibm]

uppps... coupling caps might have something to do with my mod as well...

I replaced some njm2068 with opa2132P and the sound is a bit metallic(anyway much better than with those njm2068).
The coupling caps were some ordinary 10uF elcos($.01 type) and I replaced them with 10uF Pana FC(they got nothing in parallel).

I'll try some MKT over there as I don't have enough space for MKP(only ~6mm between the leads). Should I bypass those as well?

thanks

[fmak]

[QUOTE]Originally posted by roibm
[B]uppps... coupling caps might have something to do with my mod as well...

II'll try some MKT over there as I don't have enough space for MKP(only ~6mm between the leads). Should I bypass those as well?

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Suggest you try a single BG-FK or BG-N. Be patient and wait for several weeks. The BGNs are initially more mellow and the BG-FK more expressive but slightly bright. They both improve!