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Mods for Kenwood DP 8020 CD Player Wanted

R

raj12345

New Member
Hi everybody. I am from India. I owns kenwood dp8020 audio cd player from 1990. I dont have any info on it and also dont have any service manual. It do sounds pretty good in midrange but lacks low end bass slam and highs details are not there. Can you all please guide me to modify this non restored all original cd player to sound its best in todays spec.
 
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Hard to do, making it as good as those units today, but there are a few threads about changing the audio chip to something more modern and better sounding. The Low Pass Filter is what some CD players call the chip used for this. Common one from back then is the 5532 and common replacement is LM4562 or a couple different OPA units. I used the LM in one and the OPA2228 in two different cdps neither one a Kenwood.

Do a search on the front page for those numbers or other phrases that might be along the lines of a chip swap. Also, there is a digital forum that does a bit of this discussion. DIY audio website does a lot of this discussion. Good luck.
 
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Those (OPA/LM numbers) are op-amps,and typically one would install some DIP sockets for those on the PCB so they can try what's called op-qmp rolling.
That (op-amp rolling) is the process of trying various combinations of op-amps to get the desired sound quality traits one is after.
Op-amp rolling is usually one of the areas where the most noticable gains can be had in a typical CDP like this.

The 2x Burr Brown PCM1701P DACs used in that Kewood unit are well regarded by most sources.
There is no reason to mess with those @ all.

The digital filter in that Kenwood DP-8020 is a Nippon Precision Circuits SM5813AP and is an 8x over-sampling affair.
IIRC that NPC filter is pin compatible with the Burr Brown DF1700 digital filter.
So that would be another thing that one could try.

Just remember those digital filters are both SMD's so some soldering would be required.

Beyond that recappping is often considered SOP.
And on occasion there are other lesser mods for some units,but info for those tends to be harder to come by.

HTH

Bret P.
 
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In addition to replacing the op amps (highly encouraged) I’d also replace the capacitors in the audio path with audio grade capacitors.
Personally I like the Nichicon Muse series.
 
But i wish to have mods to make it sound bigger and fuller with detailed treble and full bass.. Its sounding quite dry and treble + bass is lacking.. I found service manual for this on hifiengine as its same as DP7020 model.
 
dr*audio said:
Replacing the opamps with LM4562 will make the bass more solid and the highs smoother and more liquid.
Click to expand...
This ^^^^.

If you're looking for a step-by-step "how to" for your CD player it's probably not gonna happen.
So you (or your technician) need(s) to have some experience with this sorta thing and have a good idea what we're talking about to move forward.

These PCM1701P based CD players are fairly rare units as that DAC just was'nt used in a ton of different models.
Only three brands (Denon,Kenwood & Luxman) used them and something like only 13 different models of those 3 brands used them.
So it's not gonna be one of those super popular CD players that you'll find eveyone modding.

As stated the op-amp "mods" should get you what your after on their own right.

Beyond that normal servicing of the caps is a good idea too.
And that too can be considered a "mod" if you use better grade caps as was mentioned above.

Aside from those items you would likely be reaping much smaller gains with any further mods.

I know most of this because I own a Kenwood DP-5020 that has the PCM1701P DACs in it.
It's in my "to do" stack,,,with a TON of stuff ahead of it...

HTH

Bret P.
 
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Thanks all members for your kind reply.. Still i wants to know better mods for improving sound.. Means which capacitors needs to be increased in value or tell more about signal path caps so i may improve all of them..
 
You are getting a generic answer because the schematic and service manual for this unit is not out there for us to grab and look over. Even with those docs, I'm not one to know how to reengineer the unit for state of the art sound. Maybe if the schematic showed up in legible form with the cap values and such, someone could make some recommendations. I only did the chip in my Sony, very happy, not worried about the caps. Maybe later.
 
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