Denon DCD-510AE Upgrading

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Hello!

I´m about to modify my Denon DCD-510AE CD-Player!

Therefor I have some questions and i hope you´ll help me :D

1. I will replace the four 70xx-like fixed-voltage regulators by some shunt-regulators I think, replace the two crystals by two Kwak-Clocks and remove the muting-transistors.
Is there anything else I can do at moderate costs?

2. Are there four muting-transistors? Q701, Q702, Q801, Q802? And do I only have to remove these? Or should I maybe also remove C709, C809 and R712, R812?


Greetings,
Max
 

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You will have a bigger impact if you replace the OpAmps then removing the muting transistors.
The NJM2068 that are there are better sounding than the usual NE5532, but I found out that LM4562 sound even better in there (I have some Denons that have the same PCM1791 DAC).
I have tried removing the muting part on different players and I think it is more placebo than reality...
 
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Hello :)

What do you think of the OPA2134? Because it would be much easier to get for me than a LM4562.

And a further question: For the kwak-clock i need a J309 RF Amplifier. Does anyone know a similar Part? Because I´m not able to find it anywhere here in Germany... :confused:
 
I would personally go OPA2134, which remain my personal favorite opamps. I would urge, though, that you give them extra power supply filtering, in the form of a 220uf or larger, preferrably Nichicon electrolytic, paralleled with a decent size propylene or styrene film cap, from each supply pin to nearest ground. Makes a huge difference.
You can also definitely delete the output dc blocking caps, as they are totally unnecessary, since the opamp outputs should be near enough to zero volts to be perfectly fine.
 
I did try OPA2134 and those where ok too. Not too much difference from NJM2068 that you have... Personally I felt that LM4562 where better thou.

I don't think removing the output caps - quality ones - will increase the SQ. You can try to parallel some 0.1-0.22 uF polypropylene on them. That's easy to try. Removing them will leave DC going to the muting transistors and that could make them sound worse.
I feel that it is safer to leave them in place.
 
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That's good :D
Well - you have already a list. Go ahead and try those changes and try to listen to the results.
What I did on mine, I changed the OpAmp on one channel only and compared with the other. You can do the same with the output condensers or muting transistors (that's how I found that there was no difference if I removed the transistors in my Denon or Philips).
Your results might be different since it is a different player, with different amp/speakers and different set of ears :)
 
Okay, first results:

Excluding the noise when turning the player off, I couldn´t realize any difference without the transistors... So i think I will just solder them back onto the PCB.

Now i will desolder one Cap... lets see :p


Edit: Will a LT1016 also work instead of a AD8561/Max913 for the kwak-clock?
 
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Okay, first results:
Excluding the noise when turning the player off, I couldn´t realize any difference without the transistors... So i think I will just solder them back onto the PCB.

That was exactly my experience too... A lot of people swear on this "mod" but... I guess it is just placebo.
Try bypassing the output caps with some 0.1-0.22uF ones - it's easy and should improve the high freq response. But... if the existing caps are very good, you won't hear anything. This mod it is easy to check - just solder one end and touch the other (player working) to see if you hear a difference.
 
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If you haven't tried OPA2134's without also adding big, nice supply lytic & film caps right at the pins, as I described in my previous post, then you have NOT heard what a 2134 can do. It is MILES better than a 2068. There's simply no comparison.
As for the output coupling capacitors, there is a LARGE advantage in eliminating them. When not necessary, as in this case, capacitors of any sort are going to have some effect on the sound, so you will gain at least some measure of transparency by deleting them, usually a large measure of transparency.
 
2134 in my setup was just mildly better than 2068 and sensible less SQ than 4562. I have on my desk some AD8599 but I didn't have time or motivation to test them - I am happy with the 4562. And AD8599 are recomended for input impedances less than 1kohm anyway.
Another one that sounded good in my setup (folowing PCM1791A) was OPA2228. I have the impression that was better sounding than 2134.

Decoupling was done proper and extra electrolytic caps added on rails.
No caps or good caps in pairs as I said before made no difference to me. I am weary to leave the output without DC blocking OR some kind of DC control loop.
But that's just me.
 
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Well... its pretty warm I would say. I can still touch it for a longer period of time!
Normally I wouldn´t mind if a IC, for example the Driver-IC gets that warm, but this IC actually doesn´t really have any load... :confused:
 

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This issue with the decoder chip is very strange & rather disturbing. I doubt very much it is the cooling of your breath, but rather the moisture. Either this is characteristic of an extraordinarily sensitive chip, with input pins at very, very high impedances, or there is something wrong with it's installation, i.e., borderline cold solder joints, sloppy soldering where one or more pairs of pins are extremely close to shorted together, or something else weird. Both of these types of soldering issues should show up with physical stressing(tapping, flexing, etc.), so if the symptom only shows up with breath, then it's not at all likely a soldering issue. As 'something else weird', that is where diagnosing the fault gets tough. However, if there is no symptom in normal playing, it seems to me that it's no worth worrying about unless it progresses.
 
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