Marantz CD63 & CD67 mods list

[awpagan]

Does anyone have the list of components by circuit reference?


usually is in the service manual

allan

[Fidelity Audio]

Originally posted by awpagan
Does anyone have the list of components by circuit reference?


usually is in the service manual

allan

I only have 63 manual mate but I think Ray has 67

[6h5c]

Originally posted by poynton
Hi.

Not having diagrams for the 57/67 , I did not know that !
Are the post-dac components the same??

Yes, the analog stage is the same, except for one 220u inductor.

Hi.
With only the 1000p cap and no inductor, it would roll off at 6db/octave (??) rather than notch? what would be the knee freq.? I can't compute - no software.

What effect would there be in adding an extra RC ( 10k/120pF ) stage in front of the first op amp?

Similarly, adding an extra 10K and 1000pF ( and for 57/67 an extra 220uH ) between the op-amps??

Andy

Hi guys,

Been simulating some more, and for those who are interested: here are the results. First I simulated the original CD63 and 67 filter to see what that does. This is the first schematic. The notch frequency in the CD63 is at 339kHz, and as you can see in the first graph, the group-delay is not very constant in the last area of the audio-band.

Now I took Pedja's advice and changed both filters so the group-delay is more constant. I also re-tuned the notch filter to better match 8*Fs. The inductor value is the least flexible with available values, so I started by lowering the 1000p cap and matching an inductor with it, to tune the notch filter. Then I raised the two 10k resistors a little to make the group delay as flat as possible.
If you own a CD67 and you wish to leave the notch out, you can find those values too in the second schematic. The resistors are optimised for a more common 470p cap.
The second graph clearly shows a more relaxed group delay but the cost for that is about 1dB roll-off at 20kHz. The notch is not visible here, but it is at 353.9kHz theoretically.

Regards,

Ray.

[Fidelity Audio]

Nice one Ray

So are you happy with this cap / inductor setup or are there more experiments to come.

Have you listened to the player with the different values in?

[awpagan]

ray
group delays

now you've done it.

i'm going to have to time align my speakers

allan

ps nice work.

[6h5c]

Thanks guys.

Brent,

I have the 470p in my CD67, instead of the 1000p, but not the notch filter. My impression is that the highs are more "clean", less grainy. I still have to listen to it with the notch filter in, but I have to wait for some parts.

Allan,

Would you like me to scan the CD67 parts list? (need I ask?)

Regards,

Ray.

[6h5c]

Originally posted by awpagan
ray
group delays

now you've done it.

i'm going to have to time align my speakers

allan

ps nice work.

I had to move some pots and plants in the living room, 'cause I noticed a slight diffraction of the highs on the right hand side of the stereo image after this mod

Ray.

[Fidelity Audio]

Originally posted by 6h5c


I had to move some pots and plants in the living room, 'cause I noticed a slight diffraction of the highs on the right hand side of the stereo image after this mod

Ray.

hehe

On a silly note, has any one cupped their ears forward when listening to music, very open and bright

I get bored sometimes

[6h5c]

Originally posted by rowemeister
hehe

On a silly note, has any one cupped their ears forward when listening to music, very open and bright

I get bored sometimes

I must admit I sometimes do that
Very directional listening, that is. Especially when there's OTHER noise, like in the kitchen

Ray.

[SimontY]

Originally posted by 6h5c
I had to move some pots and plants in the living room, 'cause I noticed a slight diffraction of the highs on the right hand side of the stereo image after this mod

Ray.

Hi,

Funny you should say that because I had a bit of a listening session last night and felt that this player is starting to expose weaknesses elsewhere. I have some simple DIY diffusers (2x 'poly' and 1x spiky), but there's a bit more wall that needs dealing with....

I very much enjoyed listening to the Peter Malick gp featuring Norah Jones, Diana Krall, Katie Melua and Eleanor McEvoy. Funny how I had an urge to listen to female vocals

I do feel that I need to work on my psu now, as the sound is still not 100% there (and I thought it was at one point). The simpler passages are scintillating, but when it gets dense there's just a little confusion (partly room reverb tho). The bass is great, the mids are good, but the treble is not realistic. However, I've never heard realistic treble recorded really, and partly of course it takes a good tweeter (mine is good, not great - Seas NoFerro 900, PP film/foil cap).

People who doubt the importance of a great source need to hear my hi-fi, or indeed any of our modded CD63/7s.

I am going to add a transformer or two, schottky diodes and some LM317 regs and feed a few parts with dedicated regs. I'm yet to decide whether its huge overkill external macho psu, or delicate small psu in the cd63. The latter option is risky for a newby like me, as it means I'm more likely to break things. The former option of course allows oversized transformers, and as many as I like, and huge unnecessary smoothing caps, which I have (cheap using Ebay). I have yet to see the 'mine is bigger than yours' approach to the psu on this cd player!

Simon