The best sounding audio integrated opamps

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rbmartin

Member
Joined 2012
I know this is an old thread but I wanted to put in a plug for the LME49713. I rebuilt the line stage in my old Adcom GFA-565, replacing the LT1056/LT1010 composite with LME49713HA (metal can of course!). This is the most transparent gain stage I've ever heard. Sad that these parts were discontinued. Actually it's kind of hard to believe they ever got produced in the first place. If you're not careful they also make a good VHF transmitter.
 
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dreamth

Account Closed
Joined 2010
Salas said:
At such signal levels splendid. Nice square wave edges on the scope too, less peaky than most others in the raw. Only 3.3pF across a 10k R feedback in the G=10 inverting test mode sorted it out.

Used to have an expensive enough Denon CD Player in the 90s and I remember it sounding surprisingly great if with LM833 at its output, better than with anything different I had tried there. Its an easy going chip makes no fuss.
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I thought that denon's were exclusively using upc4570 in the i/v converter and ne5532 after the filters.Philips was into lm833 and JVC used m5220 which i personally found to be awesome.Unfortunately m5220 only got into cassette players along with m5219, njm2043 and njm2068.Unfortunately extinct there was a jewel that dissapeared too: njm2041 which was in between 2068 and 2043 but then njm2114...Of all the op-amps i tested from that period, lm833 had the highest gain when used with the same feedback network and that indicated a muc higher input impedance.It really behaved well no matter where i put it in. I never compared it to upc4570 though...i have a feeling they are at the same level except maybe output power.
With time i got to buy all sorts of fancy op-amps, but in the end i came back to the old ones as i learned to use them properly...and the new ones i keep only for very special projects because unfortunately , newer chips aren't too versatile, they look more like speciliazed chips for certain aplications .
 
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dreamth

Account Closed
Joined 2010
Salas said:
Dolby were not alone. I just dug up pictures from a well preserved cassette deck I was aligning some months ago. Was initially well out for heads height, azimuth, and bias. Many hours later a nice result even for a TDK-D graph (-20dB actual REC level).

The three head Nakamichi DR-2. Introduced in 1992. This is a made in Taiwan unit from 1995. Not a sharp shot but JRC proudly stamped on the eight legged bugs is still visible. Those are mainly 1V/us NJM4558. In many models including the CR-7.

They never let go of those NJM and their boosted derivatives until they stopped making decks. Even when they had the good sensibility to use low THD green bipolar Nichicons in selected places of their later years decks as seen in the photo.

Legendary Nakamichi sound is partially NJM old industrial op-amps sound as well. A historical reality. :cool:
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Pioneer went with m 5218 for the same jobs done by njm4558, although way more powerful and good for headphones amplifiers too. Denon and Technics went with m5219 in their casette players, M5220 was the best in that line and preffered by Pioneer, Aiwa, Sony in the late 90...2000.I still hate that m5220 dissapeared.Best suited for phono.I dig in every cassette player i get for m5220.
Yet Nakamichi also went with TL072 and the last one, njm2043 which for me was a revelation.I use njm2043 and njm2068 from scraped old fostex and teac multitrackers extensively and just forget about the new chips...they are just so good! At the same time m5218 was the chip that simply changed all my perspectives on high slew rate op-amps because it has a low one, but perform like a faster one and i figured out one very simple thing that many engineers forget: slew rate is the ability to pump enough current into a dead short quicly but you first need the ability to deliver that damn current so it's useless to have a huge slew rate op-amp that can't deliver the needed current and i found tons of op-amps with slew rates like 1000v/us whose slew rate gows down too 50...100v/us on 22pf load...
 
Salas

Salas

diyAudio Chief Moderator
Joined 2002
Paid Member
DaveElson said:
I'm trying hard not to double post - new member here and did earlier ask about Op Amps in the digital section.
Interested (in part) about JRC 4580D's in my Onkyo 7030 C.
Any advice is really appreciated. Did not see this thread until later.
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I had replaced those with various types once in a Denon DCD-1400 to see if I would like something else better. Its many years ago but I remember it did not react well to other than its own JRC 4580D and LM833. Acquired some harshness with other. I subjectively preferred it with the LM833.
 
tiefbassuebertr

tiefbassuebertr

Member
Joined 2005
tiefbassuebertragung.de
The output signal in general is taken from the output PIN. But in some cases the output signal is taken from the power supply pins - go to page 4-59 under
https://www.analog.com/media/en/tec...tes/58052492001115525484056221917334AN211.pdf
Check also out in this case also this threads:
Power Amp Front End with integr. OpAmp and Signal Pad by Power Supply Rail - Naming?
Power Amplifier with Small Signal OP-Amp in the Front-End - Overview wanted
What are the best sounding audio integrated opamps in this application ?
Are here the same or other rules valid?
 
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Frederico Acardi

Member
Joined 2018
Hello, I need to choose 2 opamp for 2 places in my circuit.
The PSU is +15V/-15V. I am looking for the lowest added noise.
Both opamps will act as buffer.
I am looking into the LME49721, the OPA828 or the LT1793.


If you have other recommandations of opamp (CMOS or Jfet) that would give me the lowest added noise, you are welcome. I don't care about the price, I want the lowest noise.

First place buffer :
RSource=10K >>> OPAMP >>> RLoad=5K

Second place buffer:
RSource=90K >>> OPAMP >>> RLoad=5K

Thank you.
 
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Frederico Acardi

Member
Joined 2018
Thank you Salas I will check your recommendations !

I think the opa1642 will be lower noise with 90K impedance, since it's a buffer I don't use gain, the lower current is better ?



Kokoriantz, can I do it in LTspice ? Do you have a project template to check noise ?


Or maybe should I just go discrete components, since I am building the pcb myself ?
and use a single TO92 Jfet ? will it be the lowest noise buffer ?
 
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Frederico Acardi

Member
Joined 2018
Thank you guys, I did it it costed me a day but I figured it out.

I did test the OPA1641 LT1793 OPA828 in ltSpice with 10K 90K and 200K (just for test) and they measure almost the same I am always in the same ballpark !
With 200K RSource at 1KHZ I am at 42.0000567nV(LT1793) and 41.873054nV(OPA1641) and 42.124678nV(OPA1656).



I will just buy the cheapest.


Can you recommend me a good Jfet to try to model the noise ?
To see if it's worth it versus a simple opamp.
 
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