Hello,
I bought a nice NAD 5325 CD-Player (because of the classic design) but now I am studying the layout in order to make some tweaking.
I would like to swap from Op-Amp NJM4565 to NJM4580. Because it is the successor op-amp, I hope that it could be a good "drop in replacement". I think this is less risky than other op-amps discussed as a replacement for the NJM 4565 like NE5532, NJM2068 or LM4562...
As I am not too much familiar with electronics I would like to hear the opinion of someone who kows a bit better than me.
Due to the schematic is the op-amp swap possible?
http://www.njr.com/semicon/PDF/NJM4565_E.pdf
http://www.njr.com/semicon/PDF/NJM4580_E.pdf
Schematic of the NAD 5325 CD-Player:
http://www.filedropper.com/nad53205325
Gruß, Dragan from Germany
I bought a nice NAD 5325 CD-Player (because of the classic design) but now I am studying the layout in order to make some tweaking.
I would like to swap from Op-Amp NJM4565 to NJM4580. Because it is the successor op-amp, I hope that it could be a good "drop in replacement". I think this is less risky than other op-amps discussed as a replacement for the NJM 4565 like NE5532, NJM2068 or LM4562...
As I am not too much familiar with electronics I would like to hear the opinion of someone who kows a bit better than me.
Due to the schematic is the op-amp swap possible?
http://www.njr.com/semicon/PDF/NJM4565_E.pdf
http://www.njr.com/semicon/PDF/NJM4580_E.pdf
Schematic of the NAD 5325 CD-Player:
http://www.filedropper.com/nad53205325
Gruß, Dragan from Germany
Hello,
nice news that you consider the lm4562 as a good drop in replacement. As I heard that wide bandwidth op-amps could make problems when replacing op amps with smaller rise time.
Where can I get an adaptor from dip to sip ? As this is a very rare format I considererd the NJM4580 as an easier drop in.
Bye, Dragan
nice news that you consider the lm4562 as a good drop in replacement. As I heard that wide bandwidth op-amps could make problems when replacing op amps with smaller rise time.
Where can I get an adaptor from dip to sip ? As this is a very rare format I considererd the NJM4580 as an easier drop in.
Bye, Dragan
I haven't seen any DIP to SIP adapters (doesn't mean they don't exist though).
SIP can be either 8 or 9 pin but if you look at the opamp pinouts in the data sheet you will find you can solder pins 1 to 4 of a DIP directly into the board and then neatly hardwire the remaining pins. I would also add a small electrolytic of around 4.7 or 10uf directly across pins 4 and 8 of the DIP device.
SIP can be either 8 or 9 pin but if you look at the opamp pinouts in the data sheet you will find you can solder pins 1 to 4 of a DIP directly into the board and then neatly hardwire the remaining pins. I would also add a small electrolytic of around 4.7 or 10uf directly across pins 4 and 8 of the DIP device.
Thank you very much for this tip, I think I will make a try.
I usually have put 0,1 mfd between pins 4 and 8 on other projects with astonishing effect, did not know that this condenser could be a bit bigger. I still have some WIMA 50 Volts 10mfd for the output stage (original was non-polar 22mfd electrolytic which I replaced). Maybe these will do between leg 4 and 8....
On the pcb of the NAD 5325 I found out that the 78L06 and the 79L06 which drive the op-amps have no capacitors between their legs. I added 2 times 1mfd between the legs on both regulators.
The NJM4580 did arrive - I have ordered them in sip-format. But now I become courageous to order the LM4562 which has a really good technical data. Must be sonically something like a revolution.....
Bye, Dragan
I usually have put 0,1 mfd between pins 4 and 8 on other projects with astonishing effect, did not know that this condenser could be a bit bigger. I still have some WIMA 50 Volts 10mfd for the output stage (original was non-polar 22mfd electrolytic which I replaced). Maybe these will do between leg 4 and 8....
On the pcb of the NAD 5325 I found out that the 78L06 and the 79L06 which drive the op-amps have no capacitors between their legs. I added 2 times 1mfd between the legs on both regulators.
The NJM4580 did arrive - I have ordered them in sip-format. But now I become courageous to order the LM4562 which has a really good technical data. Must be sonically something like a revolution.....
Bye, Dragan
The cap size isn't all that critical and a 'lossy' electrolytic generally works very well.
Cap type and size is more of an issue when there is a definite pre-existing problem to be fixed (such as spiky rails from a switching supply) rather than simply adding something to maintain a low impedance.
For wiring the 4562 you should find that 'resistor leg offcuts' are perfect. Just bend to a suitable profile and neatly solder. The 4562 has become one of my favourites, the other is the OPA2604 but unfortunately that has hit production problems (performance can not be guaranteed over the full extended supply voltage range) and so is likely to be unavailable for some time.
Cap type and size is more of an issue when there is a definite pre-existing problem to be fixed (such as spiky rails from a switching supply) rather than simply adding something to maintain a low impedance.
For wiring the 4562 you should find that 'resistor leg offcuts' are perfect. Just bend to a suitable profile and neatly solder. The 4562 has become one of my favourites, the other is the OPA2604 but unfortunately that has hit production problems (performance can not be guaranteed over the full extended supply voltage range) and so is likely to be unavailable for some time.
Yes, I liked the OPA2604 but after some time I more liked the OPA2134 - seems a little bit more neutral to me.
But the technical data of the LM4562 is awsome, I have ordered them now.
I will "stretch out" the legs on both sides and the four ones facing upwards will be hard wired with some isolated flexible cable.
The WIMA 10mfd 50 volt will then be directly wired from pin 4 to 8. As four pins will be soldered directly into the pcb mechanicallly it should be stable enough.
This fat foil capacitor should be mechanically fixed. Will see how to do that. You think a small electrolytic one would do for better impedance? Maybe the non-polar 22mfd from the original output stage which are now out of work are easier to use.... will see.
Nice idea.
When finishing the tweak I will post here with fotos.
As a starting I used the tweaks for the NAD 5325 from this page:
NAD 5320 (5325) | Goldfich-mod
"Mr. Goldfinch mod" made some nice propositions which I could decipher by using translating machine from polish to german.
Further I replaced six diodes to fast soft recovery diodes and did the tweak to the 6 Volt regulators for the op-amps. Maybe all these tweaks do not really do something sonically but the op amp with better data will certainly be audible.
Bye, Dragan
But the technical data of the LM4562 is awsome, I have ordered them now.
I will "stretch out" the legs on both sides and the four ones facing upwards will be hard wired with some isolated flexible cable.
The WIMA 10mfd 50 volt will then be directly wired from pin 4 to 8. As four pins will be soldered directly into the pcb mechanicallly it should be stable enough.
This fat foil capacitor should be mechanically fixed. Will see how to do that. You think a small electrolytic one would do for better impedance? Maybe the non-polar 22mfd from the original output stage which are now out of work are easier to use.... will see.
Nice idea.
When finishing the tweak I will post here with fotos.
As a starting I used the tweaks for the NAD 5325 from this page:
NAD 5320 (5325) | Goldfich-mod
"Mr. Goldfinch mod" made some nice propositions which I could decipher by using translating machine from polish to german.
Further I replaced six diodes to fast soft recovery diodes and did the tweak to the 6 Volt regulators for the op-amps. Maybe all these tweaks do not really do something sonically but the op amp with better data will certainly be audible.
Bye, Dragan
Differently than on the goldfinch website I did not change the big 2200 mfd to 3300mfd like he proposed. As I have no good experience in making these ones bigger in other projects.
Depending on the transformer - when these are dimensioned to be an exact match in current the bigger electrolytic will generate more distortion...
bye, dragan
Depending on the transformer - when these are dimensioned to be an exact match in current the bigger electrolytic will generate more distortion...
bye, dragan
Everyone has their own ideas on the caps and I would use a good commercial quality electrolytic.
An imaginary case... a noisy rail with lots of high frequency hash from an SMPS. Adding a well meaning high quality 0.1uf (say a ceramic) could in some circumstances cause the noise to be 'altered' or even increased as the cap interacts with the inductance of the series PCB print. The 0.1uf in series with a 1 ohm might be better in that case.
As a general rule I find the 'lossy' electrolytic tightly coupled (electrically) to the opamp works really well.
An imaginary case... a noisy rail with lots of high frequency hash from an SMPS. Adding a well meaning high quality 0.1uf (say a ceramic) could in some circumstances cause the noise to be 'altered' or even increased as the cap interacts with the inductance of the series PCB print. The 0.1uf in series with a 1 ohm might be better in that case.
As a general rule I find the 'lossy' electrolytic tightly coupled (electrically) to the opamp works really well.
Here is a good SOIC to DIP board, that are well made and fairly cheap.
https://www.sparkfun.com/products/13655
+1 for Mooly's recommendation of the LM4562, I like that op amp too, too bad it went SOIC only.
https://www.sparkfun.com/products/13655
+1 for Mooly's recommendation of the LM4562, I like that op amp too, too bad it went SOIC only.
Hello,
thank you all for the nice support!
Here you can see some fotos of the tweaking of the NAD 5325.
https://goo.gl/photos/2ntaKgVjJsD7VRtT7
Now it sounds very nice. The dac does not have the resolution like more modern dacs but the sound is very pleasant.
I bought a second NAD 5325 for making a listening comparison. It has a mechanical defect which I will have to fix before making the listening test modified - unmodified.
Bye, Dragan from Germany
thank you all for the nice support!
Here you can see some fotos of the tweaking of the NAD 5325.
https://goo.gl/photos/2ntaKgVjJsD7VRtT7
Now it sounds very nice. The dac does not have the resolution like more modern dacs but the sound is very pleasant.
I bought a second NAD 5325 for making a listening comparison. It has a mechanical defect which I will have to fix before making the listening test modified - unmodified.
Bye, Dragan from Germany
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