Change or replace a LM358 with a NE5532

[leosep]

Hi, how are you all?

I have 2 of the velleman k1803: https://www.velleman.eu/downloads/0/illustrated/illustrated_assembly_manual_k1803_rev2.pdf

Can i replace the LM358 with a NE5532 to lower the noise or hiss without replacing any other component?

I'm powering one with 12v dc and the other one with 22v dc.

 

[JonSnell Electronic]

Yes but a TL072 would be even quieter according to the Ti data sheet; http://www.ti.com/lit/ds/symlink/tl072a.pdf

 

[leosep]

But i think the TL072 will not fit the velleman k1803 without modifications.

 

[JonSnell Electronic]

TL072 is the same case and pin out as 358 and 5532.
http://www.ti.com/lit/ds/symlink/lm158-n.pdf
http://www.ti.com/lit/ds/symlink/tl072a.pdf

 

[leosep]

Oh thanks. Can i power the TL072 with 10-30VDC?

 

[epicyclic]

I think the NE5532 will be quieter . The noise on the input buffer will be dominated by the 100K series resistor then the lower voltage noise of the NE5532 will excel in the second amplifying stage. Just put a 0.1uF ceramic capacitor across the voltage supply pins of the pcb board to assist stability ...........just my thoughts............try both and have a noise shoot out .

 

[leosep]

Thanks, can i still use 10-30v with NE5532 and TL072?

 

[epicyclic]

YES


PS ....please report back on your results

 

[leosep]

Thank You Very Much, im buying the ICs now.

 

[PRR]

....velleman k1803.... lower the noise or hiss....

That design is TERRIBLE for low-hiss work.

Not the chip-- the 100K input resistor.

Find a different kit or roll your own.

 

[rayma]

That design is TERRIBLE for low-hiss work. Not the chip-- the 100K input resistor.

All four of the input 100k resistors can be reduced to 10k. The R1 and R6 values can remain as they are.

 

[AndrewT]

That design is TERRIBLE for low-hiss work.

Not the chip-- the 100K input resistor.

Find a different kit or roll your own.

and yet we find that many claim the inverting topology is quieter than the non-inverting.

The 100k has ~40nV/rootHz compared to 4nV/rootHz of a 1k resistor.
If we assume opamp also has ~4nV/rootHz then the 1k combined with the inverting opamp will have ~ 5.6nV/rootHz and the 100k will increase the Ein to ~40.8nV/rootHz or about 17.2dB noisier compared to using a 1k input resistor.

 

[rmaudio]

That design is TERRIBLE for low-hiss work.

Not the chip-- the 100K input resistor.

Find a different kit or roll your own.

+1 It's just not suitable for a low noise 40dB gain stage whilst keeping a reasonable input impedance.

(btw PRR - I am 'Newmarket' on the other forum)