Hello
Any much better opamps suggestions for a drop-in replacement of a NJM4558D ?
That opamp output are following a PCM1710 dac, in a Denon DCM-260 CD player.
I include the schematic I have just get of that output.
Thank
Gaetan
Any much better opamps suggestions for a drop-in replacement of a NJM4558D ?
That opamp output are following a PCM1710 dac, in a Denon DCM-260 CD player.
I include the schematic I have just get of that output.
An externally hosted image should be here but it was not working when we last tested it.
Thank
Gaetan
NJM4558 is a dual opamp, nothing special, can be replaced with almost any other dual opamp...
You could also replace the caps C429/C430 with some better bipolar or film-caps.
Arne K
You could also replace the caps C429/C430 with some better bipolar or film-caps.
Arne K
If the 4558 is a dip package I would use a AD827 and bias the output into class a with about 7ma with a fet and resistor or current source and resistor. I would remove all the other parts in the output stage except for the feedback resistors and output cap.....use nude damped blackgate for coupling cap (33uf 16V N) and vishay/dale one eighth watt RN55 resistors. You do not need any output filtering whatsoever with these simple TI DAC chips.....you will get very transparent sound this way. Also use separate regulated 5 v supply for left and right analog power supplies on the DAC chip....makes a difference sonically. I used to modify MSB DACs and they used the very similar PCM 1716.
Hello
I have some Texas NE5532 but it's old tech ic's. Maby the OPA2134 but it's a fet op amp and I'm not sure it would be a drop-in replacement for the NJM4558 ?
Gaetan
I have some Texas NE5532 but it's old tech ic's. Maby the OPA2134 but it's a fet op amp and I'm not sure it would be a drop-in replacement for the NJM4558 ?
Gaetan
If all you want is drop in replacements then ne5532 should be fine. It might be "old tech" but it's also a very good op amp.
Adding in much newer opamps like the AD827 into an existing design is, IMO, asking for trouble. These new opamps are very fast, and are likely to just oscillate without due care and attention.
If you can live without the mute function, pull the two Mute transistors TR400/401. This is known to improve sound quality in many cases.
Adding in much newer opamps like the AD827 into an existing design is, IMO, asking for trouble. These new opamps are very fast, and are likely to just oscillate without due care and attention.
If you can live without the mute function, pull the two Mute transistors TR400/401. This is known to improve sound quality in many cases.
jaycee said:
Hello
About that mute fonction, is it an auto muting ? It seem that most cd player have that mute fonction, I don't see any mute buton on most cd player remote control.
Thank
Gaetan
Yeah.. could be. You can try removing them, and if you notice strange and nasty noises when idle, you can always put them back 🙂
gaetan
OPA2134 may not be quite as good as the LM4562 etc. but should plug straight in withpot any stability problems. If the inputs to the IC are well balanced you may be able to get rid of the O/P capacitors, as the OPA2134 has a very low DC out.
The muting is auto. Any gain made by pulling them out will be very small,and may not be obvious in your system. However, if one goes leaky, a fault I have had twice over the years, channel balance may be affected.
SandyK
OPA2134 may not be quite as good as the LM4562 etc. but should plug straight in withpot any stability problems. If the inputs to the IC are well balanced you may be able to get rid of the O/P capacitors, as the OPA2134 has a very low DC out.
The muting is auto. Any gain made by pulling them out will be very small,and may not be obvious in your system. However, if one goes leaky, a fault I have had twice over the years, channel balance may be affected.
SandyK
sandyK said:
Hello
"should plug straight in withpot" What is withpot mean ?
I'm french speaking so I miss some english worlds.
Thank
Gaetan
NJM4558D
Gaetan
That is what happens when you type too quickly without checking.
Should have been "without"
SandyK
Gaetan
That is what happens when you type too quickly without checking.
Should have been "without"
SandyK
Hello
Is the OPA2134 are very much better sounding than NE5532 ?
In the specs sheet the distortions of the OPA2134 are raising much more in high frequency than the NE5532.
Thank
Gaetan
Is the OPA2134 are very much better sounding than NE5532 ?
In the specs sheet the distortions of the OPA2134 are raising much more in high frequency than the NE5532.
Thank
Gaetan
NJM4558D
gaetan
I (and others) replaced the NE5532s in a Musical Fidelity X-DAC V3 with OPA2134 , and there was a marked audible improvement.
SandyK
gaetan
I (and others) replaced the NE5532s in a Musical Fidelity X-DAC V3 with OPA2134 , and there was a marked audible improvement.
SandyK
gaetan8888 said:
Muting is for power on, power off, and when the DAC is not receiveing any signals.
On the three CD players I have removed mute transistors from, the only sideeffect was a very low 'pop' when turning on the player. The improvement in sound quality of this operation is quite big, so Just Do It .
NE5532= very organic, natural sound.
OPA2134=Detailled, precise, analytic sound.
Both of them are way better than NJM4558.
Replace the NJM4558 with a 8pin DIL socket, then you can experiment.
Replace output caps, or parrallel them with 0.1-1uF polypropylen, wich improves midrange and treble detail and clarity.
Keep 600 ohm output resistors for lesser impact of interconnect cables.
Locate Power supply capacitors closest to DAC, and double up their value - this gives a big improvement in bass accuracy, sound stage stability and midrange detail.
NJM4558D
Gaetan
The suggestions from Nrik are very heavily biased by personal preference, and the actual equipment in use. There is no universal solution for opamp replacement. However, either of the opamps mentioned will sound better than the NJM4558D.
Many recent opamps have a very low DC offset, so it may be possible to s/c the existing O/P capacitors. This will give better audible results than fiddling with the capacitors.
Regarding the suggestion to increase the output resistor to 600 ohms, this may result in HF rolloff ,and damage the integrity of the upper harmonic structure. Let's face it, the majority of the designers aren't dummies, the resistance values are selected to optimise performance of the equipment concerned when using standard coaxial type ,shielded interconnects.
Using some "snake oil vendor" designs or DIY interconnects may result in what appears to be an overbright top end response. This is not the fault of the player! Willy nilly doubling the size of
the power supply capacitors nearest the DAC may slow down the response of the voltage regulators, and again will not necessarily give the expected results in all equipment.Low ESR capacitors are NOT desireable in this location either.
That is my 5 cents worth, so I will leave it to others to make any further comments.
SandyK
Gaetan
The suggestions from Nrik are very heavily biased by personal preference, and the actual equipment in use. There is no universal solution for opamp replacement. However, either of the opamps mentioned will sound better than the NJM4558D.
Many recent opamps have a very low DC offset, so it may be possible to s/c the existing O/P capacitors. This will give better audible results than fiddling with the capacitors.
Regarding the suggestion to increase the output resistor to 600 ohms, this may result in HF rolloff ,and damage the integrity of the upper harmonic structure. Let's face it, the majority of the designers aren't dummies, the resistance values are selected to optimise performance of the equipment concerned when using standard coaxial type ,shielded interconnects.
Using some "snake oil vendor" designs or DIY interconnects may result in what appears to be an overbright top end response. This is not the fault of the player! Willy nilly doubling the size of
the power supply capacitors nearest the DAC may slow down the response of the voltage regulators, and again will not necessarily give the expected results in all equipment.Low ESR capacitors are NOT desireable in this location either.
That is my 5 cents worth, so I will leave it to others to make any further comments.
SandyK
before using 5532's i would verify that the power supply will handle the extra current. iirc 4558's run about 10-30ma supply current, 5532's run in the neighborhood of 100-200ma. not a problem with one or 2 on a board, but (like in a mixer, etc...) if you have more than 3 or 4 of them they will fry low current power supply regulators like 78L12's
NJM4558D
unclejed
The Texas Instruments NE5532 data sheets show a total current of 8mA typical,16mA maximum. Perhaps you are confusing this with short circuit output current, which is quoted as 10mA minimum,38mA typical, and 60mA maximum ?
SandyK
unclejed
The Texas Instruments NE5532 data sheets show a total current of 8mA typical,16mA maximum. Perhaps you are confusing this with short circuit output current, which is quoted as 10mA minimum,38mA typical, and 60mA maximum ?
SandyK
Say what?
A dual 4558 draws 3.5 ma and a 5532 draws 8ma.....maybe you have the Godzilla version.....you are very confused! Heck most class A/B power amps are not biased more than 200ma on the output......this is a freakin tiny op amp!
Sandy,
you beat my post by about 10 seconds......far out!
A dual 4558 draws 3.5 ma and a 5532 draws 8ma.....maybe you have the Godzilla version.....you are very confused! Heck most class A/B power amps are not biased more than 200ma on the output......this is a freakin tiny op amp!
Sandy,
you beat my post by about 10 seconds......far out!
Hello
I can't use a 8pin DIL socket, the 4558 op amp are hard to reach, I did unsoldered it by going under the cd player, and I can only push the replacement op amp ic into the place by the side of the board since it's under a kind of case bridge. So it's a one time change of that op amp.
Thank
Gaetan
I can't use a 8pin DIL socket, the 4558 op amp are hard to reach, I did unsoldered it by going under the cd player, and I can only push the replacement op amp ic into the place by the side of the board since it's under a kind of case bridge. So it's a one time change of that op amp.
Thank
Gaetan
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