Marantz CD63 & CD67 mods list

[avr300]

Originally posted by Thomo


Hmm. Well, I'm just building all my cd67 mods into a cd63. The perfect time to be experimenting I think. Could you post a few more details about what you have done? or is it all on here already?

Cheers, Lee.

I'll try.

If you take a good look at the DAC datasheet and the PCB layout, I'll guess you can figure it out. The important part to notice is, that the DAC's AGND [i]is[/] connected to a starground at the RCA - that's AGND. The problem is that this connects to the topplane of the PBC (like all other GND in the machine).

Remember the ground to the separate PSU supplying the DAC AVDD1-4 (U200), the AVSS1 and AVSS2, that's also analog side of the DAC.

I'm not using the starground on the PCB, I pick up the AVSS1 and 2 at U197 and U198. Remove these and connect the DAC side of both to your new AGND point (mine is between my new RCA plugs.

My AGND has 4 wires.

1. U197
2. U198
3. GND to the Flea that feeds AVDD1-4 (U200)
4. GND to my supply to my discrete board.

All connected at RCA's.

That's it. Does it make sense? Sure it makes music

[RCruz]

Originally posted by avr300


I'll try.

If you take a good look at the DAC datasheet and the PCB layout, I'll guess you can figure it out. The important part to notice is, that the DAC's AGND [i]is[/] connected to a starground at the RCA - that's AGND. The problem is that this connects to the topplane of the PBC (like all other GND in the machine).

Remember the ground to the separate PSU supplying the DAC AVDD1-4 (U200), the AVSS1 and AVSS2, that's also analog side of the DAC.

I'm not using the starground on the PCB, I pick up the AVSS1 and 2 at U197 and U198. Remove these and connect the DAC side of both to your new AGND point (mine is between my new RCA plugs.

My AGND has 4 wires.

1. U197
2. U198
3. GND to the Flea that feeds AVDD1-4 (U200)
4. GND to my supply to my discrete board.

All connected at RCA's.

That's it. Does it make sense? Sure it makes music

It makes sense to me.... and it seems easy to implement also.

Of course you will need a separate psu for this modd.....

One question remains... your RCA plugs also connect to the general GND of the player ?

Ricardo

[avr300]

Originally posted by RCruz


It makes sense to me.... and it seems easy to implement also.

Of course you will need a separate psu for this modd.....

One question remains... do you or do you not connect the GND of your discrete board to the GND in the player ?

Ricardo

GND of the discrete goes to GND of it's PSU - and on to the AGND. As a matter of fact I let the U197 & U198 enter the discrete board at it's input end and connects the grounds (left and right) at output end of the discrete to the RCA's.

This picture illustrates it. 3 wires in at input end, LO, LON and U198 (RO, RON and U197) and 2 GND wires at output end + Flea GND + analog PSU GND.

Don't get confused over the LR outputs from the discrete.

[RCruz]

Originally posted by avr300


GND of the discrete goes to GND of it's PSU - and on to the AGND. As a matter of fact I let the U197 & U198 enter the discrete board at it's input end and connects the grounds (left and right) at output end of the discrete to the RCA's.

This picture illustrates it. 3 wires in at input end, LO, LON and U198 (RO, RON and U197) and 2 GND wires at output end + Flea GND + analog PSU GND.

Don't get confused over the LR outputs from the discrete.

Are your RCA´s isolated from the player (no gnd contact)?

Do you connect your analog psu GND to mains earth ?

Splendid work.

Ricardo

[avr300]

Originally posted by RCruz


Are your RCA´s isolated from the player (no gnd contact)?

Do you connect your analog psu GND to mains earth ?

Splendid work.

Ricardo

1. Yes, isolated.
2. Main earth - do you mean protective ground? You could, but why ? You don't need to.

(I have connected mine to my own separate earth rod exclusive for my audio) - but pls. be careful - understand the potential of 230V, groundloops and shock hazard.

[RCruz]

Originally posted by avr300


1. Yes, isolated.
2. Main earth - do you mean protective ground? You could, but why ? You don't need to.

(I have connected mine to my own separate earth rod exclusive for my audio) - but pls. be careful - understand the potential of 230V, groundloops and shock hazard.

So in reality you have two separate PSU in the player...
1 - Psu Digital + GND on the main PCB
2 - Psu Analog for the dac and output discrete + One common AGND.....

And you do not connect both GND ever.

I never tried it because I believed some kind of (gnd leverage) was needed to make things work.

This is a major modd.

The sound must be so much better...

Very impressed.

[avr300]

Correct, DGND and AGND newer meets. Separation point is the DAC.

[RCruz]

Thank you... this has been really enlightening.

I will surely try this modd.

No more digital contamination on the analog signal..!!!

It must sound really good.

[jimh0612]

Originally posted by RCruz

State of the Art....

Relating to sregs, I am using 317 based ones, built using red leds instead of resistors to set the voltage. Also using a capacitance multiplier. On the outputs I have Cerafine and BG depending on the reg use.

Here you have the components:
R122 (+5v PSU DIGITAL) +5V Sreg (LM317 + 2xRed Led bypassed by 220uF Elna + 121r (pins 1-2) + gyrator (BC550C + 120uF Pana FC) + 100uF25v ELNA Cerafine output

R123 (+5v PSU ANALOG) +5V Sreg (LM317 + 2xRed Led bypassed by 10uF Tant + 121r (pins 1-2) + gyrator (BC550C + 120uF Pana FC) + 220uF BG STD output

With these regs on the servo I get Deep tight bass, big overall detail improvement.

Ricardo

Hi Ricardo

Did you compare the regs with the tant and the Cerafine on the gyrator?

I have built my 5v regs with 4.7u tant/ BC547 VBE and 10u tant on the output, although I have built one with 100u/25v Cerafine on the output. I have used two 3.9v Zeners in parallel to set the voltage and get 5.3v, which I think is near enough.

I haven't had chance to fit them yet, so I cannot say what the difference is.

I'm not sure the bigger cap on the output will make a difference as I have 470u BG's as reservoir caps on the main pcb near to the chips replacing the original caps.

Peufeu said tants are not good at high frequencies nor are they good on distortion.

Although the Cerafines may be better caps, as we are talking power supply as opposed to signal purity, I am not sure what is best.

I thought smaller caps were faster, so that might be better for faster transient response.

Much as I would love to use Brent's sPower regs, I cannot afford them, so my solutions must be home made.

I know Simon and Thomo are mightily impressed with them for speed, etc, but I'm not sure what makes a reg "fast".

Regards

Jim

PS good luck with separating the grounds.

[Thomo]

Originally posted by jimh0612


I'm not sure the bigger cap on the output will make a difference as I have 470u BG's as reservoir caps on the main pcb near to the chips replacing the original caps.

If you mount the regs right next to the BG on the main board, you shouldn't need the output cap on the reg itself.

I use all my regs like this and have found it a small improvement.

Someone correct me if I'm wrong though.

Lee.