Direct upgrade for JRC NE5532 ?

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Greetings,

I'm experimenting with few amp. designs and one of the boards I ordered (based on TI Tas5613) use two JRC NE5532 opa.
Originally we intend to upgrade it with opa2353, but apparently it wouldn't work due to this op using single 5v power supply.

Any other direct replacement with better performances?

I'm trying to optimize my build for better sound reproduction and would hate to have components notoriously known for distorting data.

Any other information needed to decide on the replacement?

I might also experiment with some TUBE buffers - maybe I can use a TUBE stage instead of these opa ?

Regards,
Gal
 
OPA2604 is still one of my favourites...

have you used the search function :)
http://www.diyaudio.com/forums/chip...g-audio-integrated-opamps-51.html#post2012422

Great link - thank you :)
It's just that I'm limited by the PCB maker inventory.
The board originally had two NE5532 and we agreed on upgrading with opa2353 but he had problems fitting it w/o further modification to the PCB power lines.
The only other option he currently offer is NJM2114.
Other than that I'll have to modify it myself when I'll get it.
I'm newbie and even though have decent soldering skills - I'm not sure I have the knowledge to do any other MOD than just direct replacing the OP IC's.
So only a direct replacement is preferable w/o any other modification...

Would the OPA2604 fit directly? same power requirements as NJM2114 etc?
Gal
 
Attached are spectra from an OPA2604 and a LM4562 I have tested in my DAT recorder (gain of 10 or so I believe). The LM4562 has higher 2nd harmonic (if that is what you wan´t) but higher 5th too. At least it lacks the
unfavorable 7th which the OPA2604 has. No integrated opamp will give you
"tube sound". I cannot confirm that the OPA2604 has predominantly even harmonics (at least not in the sense as a single ended class a circuit would have).
 

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Attached are spectra from an OPA2604 and a LM4562 I have tested in my DAT recorder (gain of 10 or so I believe). The LM4562 has higher 2nd harmonic (if that is what you wan´t) but higher 5th too. At least it lacks the
unfavorable 7th which the OPA2604 has. No integrated opamp will give you
"tube sound". I cannot confirm that the OPA2604 has predominantly even harmonics (at least not in the sense as a single ended class a circuit would have).

OK (I'll pretend I understood this completely...:rolleyes:),

Assuming that I'd prefer to reduce distortions as much as possible from the power amp - and perhaps use an optional TUBE stage which I'd power On/Off depend on the music - could I just bypass the integrated opamp's?
And taking the risk of asking a complete silly Q - what role do they actually have?
If I'll use a decent DAC and good quality Preamp - is there any need at all for these integrated opamps?

Thank you again guys for the information and extreme patience :cool:
Gal
 
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Whether you can "bypass" the opamps or not depends on how they are used and configured, and that can only be determined by looking at the circuit. You can't guess on that.

The distortion spectrum produced by circuits is a really interesting subject, and this seems to be one of the reasons why certain designs have that real "musical ability" factor.
Generally "even" harmonic distortion is actually pleasing to the ear, while odd harmonic isn't.
What it means is that if a 1khz signal is fed to the amp, the residual distortion products produced are for example 2khz, 4khz and so on for even harmonic distortion and 3khz and 5khz etc for odd.
That we seem able to "sense" this is remarkable given that the figures are so small anyway, but it does seem so in practice.

I haven't tried the LM4562 in anything yet, as up to now the OPA2604 has performed admirably for me.
 
Yes Mooly is right, we would need to know what the opamps are used for. Do you have a schematic of the board you ordered ? I have looked at the datasheet for the TAS5613
and it has symmetric inputs. Probably the opamps are used to convert a usual single ended signal output from a preamp to symmytrical.
 
Whether you can "bypass" the opamps or not depends on how they are used and configured, and that can only be determined by looking at the circuit. You can't guess on that.

The distortion spectrum produced by circuits is a really interesting subject, and this seems to be one of the reasons why certain designs have that real "musical ability" factor.
Generally "even" harmonic distortion is actually pleasing to the ear, while odd harmonic isn't.
What it means is that if a 1khz signal is fed to the amp, the residual distortion products produced are for example 2khz, 4khz and so on for even harmonic distortion and 3khz and 5khz etc for odd.
That we seem able to "sense" this is remarkable given that the figures are so small anyway, but it does seem so in practice.

I haven't tried the LM4562 in anything yet, as up to now the OPA2604 has performed admirably for me.

Mooly, did you try OPA2134?
Is there any diference between OPA2604 and OPA2134 and how would you describe it? They are both FET input devices. Which one do you prefer?
 
Sorry to hijack,
I use two NE5532s in my low distortion test oscilator. It is way below the floor of my HP334. Not much to boast about, but still very reasonable. I dought if a soundcard job can beat it, unless its a crazy pro external job. Im using an LED and LDR in the feedback loop. Amplitude is a bit jumpy but nowhere near as bad a PTC thermister or lamp.
This thread has me very interested as I would never even considered using an op-amp for audio(valves me, I even removed the things from my CD player), although some of the best kit back in the day used the supposedly terrible 417 to great effect. Some of the best recordings we listen to are through these bad boys or even god forbid a 301.
What I am trying to say is its horses for courses. a bad circuit will be bad and a good un can only be improved (or ruined).

Cheers Matt.
 
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Mooly, did you try OPA2134?
Is there any diference between OPA2604 and OPA2134 and how would you describe it? They are both FET input devices. Which one do you prefer?

Sorry... you didn't trigger the thread notifier (still under moderation :))

I haven't tried the OPA2134 at all.
The OPA2604 and single OPA604 I find really do have something special to offer sonically... they were particularly impressive replacing NE5534's in a DAC used as I/V convertors.
 
The OPA2134 is a lower spec version of the OPA2132. The OPAx132 amplifiers are different than the OPAx604 in that the x604 can use ±24V supplies, whereas the x132 and x134 can use only ±18V. The x134 and x132 are available in quads, where the x604 is available only in dual and singles, probably because of the power limitations of a quad package.

The x132 has much better DC properties than the x604 but otherwise similar AC performance. One oddity that I've noticed is that the x604 is a lot dirtier (audibly and on a test set) until it warms up, perhaps after a minute or so. The x132 does not exhibit this problem, which is probably not an issue, but it points to some potential layout induced thermal problems, maybe apparent with large LF, but I have not specifically noticed that.

Basically, the x604 is useful if you want to use HV power supply rails, but aside from that, I think the x132 or x134 would work just as well or better. FWIW, they all seem to sound pretty similar, so aside from DC offset issues, where the x132 can be much better, they are all pretty much equivalent.

They do sound pleasant, but numerically, they are not all that clean, so if accuracy is important, other amps could be better.
 
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