NJM4580V MSOP in pre for recording?

[dude2010]

Down to root of this thread, get me LM4562 specs in MSOP package - how?

My preamp stage, of my recorder, is filled with useless NJM4580V - need them replaced, but with what??

LM4562 - Dual High Performance, High Fidelity Audio Operational Amplifier

NJM4580V Datasheet pdf - DUAL OPERATIONAL AMPLIFIER¡¡ - New Japan Radio

[dude2010]

While we are at it, some SUPER caps rated at 49uF 50V "not too big"??
And resistors??
Both in the input stage..

[Mooly]

Originally Posted by dude2010

Down to root of this thread, get me LM4562 specs in MSOP package - how?

NATIONAL SEMICONDUCTOR|LM4562MA/NOPB|OP AMP AUDIO DUAL HF 8-SO, POWERWISE | Farnell United Kingdom

[dude2010]

What are you answering? "Package / Case:SOIC" !?

[abraxalito]

Originally Posted by dude2010

My preamp stage, of my recorder, is filled with useless NJM4580V

You know something the datasheet's not revealing? Looks like a perfectly respectable opamp from the 'sheet. What's up with it?

[dude2010]

Does it matter?
If you must know, changing the OA, and caps, significantly changes spaciness, 3D and room in the recordings. I just can't find a MSOP with good specs...

[dude2010]

I'm also looking for a way, to reduce/kill the noise of the switchmode supply if you have ideas!

[abraxalito]

Originally Posted by dude2010

Does it matter?

No it only matters to the extent that I'm curious. My own curiosity matters to me (of course) but what matters to people is entirely a subjective thing.

If you must know, changing the OA, and caps, significantly changes spaciness, 3D and room in the recordings.

Who says so? And to what opamp as a replacement?

About the SMPSU - it will be down to grounding and shielding/filtering. Which in a consumer product is normally strongly curtailed by lack of space. If its a portable recorder it will probably not be possible to maintain portability (i.e. compact shape) and fix this. What's the model incidentally?

Based on my experience I'd say fixing up the SMPSU noise would improve those 'audiophile' aspects better than swapping out that opamp.

[indianajo]

yeah, power supply noise is about steel boxes or walls, ferrite beads or toroids on wires, disk capacitors in the right places to kill RF, etc. Look at the Dynakit PAS2 preamp- two steel boxes, one for the power supply, an inner steel box for the sensitive bits. Look at an Ishida food weighing scale. They are measuring microvolt signals with a cycle time of 1 package a second some times. The switch mode power supplies are around the corner of a big steel box totally away from the measuring circuits. There are toroids on the DC wires, and also toroids wound into the AC input lines.
I made a big improvement in my disco mixer just by getting the power supply out of the steel op amp box entirely, and buying a wall transformer. I also put toroid chokes on + & - DC in, and put disk caps across the wound caps and at the op amp socket, and across the feedback resistor. Changed from 4558 op amps to 33078 or NJM4560 (both sound about same). Way quieter. There is no plug in solution to noise control. My disco mixer had a competent circuit designer, but the packaging guy was too sensitive to marketing and cost control, that part of the design was stupid. Sensibly designed packages that don't have glitz don't make it to the store shelf these days. Those kinds of products are limited to boutique stores with 1000% markup in megacities - or the internet. Look at repackaging to get rid of your SMPS noise, however hard it is. NJM4580's are a fairly competent op amp. Op amp noise is a white hiss, not any particular frequency, unless you suck too much current out of one like the LM4560, that will current limit snappily.

[Mooly]

Originally Posted by dude2010

What are you answering? "Package / Case:SOIC" !?

Well I wasn't sure what you were asking

So my link gave availability of SOIC package from Farnell and also full data sheet for that IC from an embedded link within that Farnell page.

If you are after something that would sound "better" I would suggest you at least consider and try the OPA2604 FET opamp.