Fidelity Audio

Servo psu

 

The biggest issue with the CD63 family of cd players is the poor servo driver ic power supply. This supply sags during playback and drastically effects the performance of the player, especiallly the bass regions and timing.

 

Basic ugrade

• Remove C814 on the negative rail and replace with something like the Panasonic FC 25V 4700uF.
• Remove C813 on the positive rail and replace with somthing like the Fidelity Audio SI cap 25V 22000uF. Large uF is important here. Note - you can either drill the pcb and fit to the pcb or locate nearby and hardwire down to the pcb.
• Short out the fuses as these add resistance and cause part of the volt sag problem.

Further improvements

 

Adding onto what has already been done it is best to add 7809 & 7909 regulators between the 'raw' voltage and the driver ics. This gives a very stable 'regulated' voltage to the ics. It is advisable to fit better capacitors after these regulators.

 

Doing it properly

 

To fully improve the servo issues you really need to rip out the std transformer and fit a 50VA 2x 12Vac type. You can then raise the driver regulators to 12V. When fitting the 50VA tx you then need to fit a 2x15V 30VA for the output section and a small 2x12V 1.6VA tx for the display voltage.

 

This can be viewed on this page - http://www.fidelityaudio.co.uk/brents63.html

 

 

 

 

Output section

 

Basic psu

 

• Remove C803 & C804 and replace with something like the Panasonic FC 25V 4700uF
• To further improve C803 & C804 find a way of fitting something like the Fidelity Audio SI 25V 22000uF this adds more depth, bass & smoothness.
• Remove Q801 & Q802 and replace with low noise regulators like the Fidelity Audio SPower regs. These offer a more analogue and detailed sound.
• Remove C805 & C806 and replace with something like a Rubycon ZA / ZLG 16V 470uF

Doing it properly

 

 

The best way to get the most out of the output stage in the 63 you are better off building a large external psu (like Naim and Cyrus do).

 

This can be viewed on this page - http://www.fidelityaudio.co.uk/brents63.html

 

 

Output

 

Lets assume we are removing the HDAM section that ultimately holds back the performance of the cd player.

• Remove C611, C612, C613 & C614 and replace with something like a Rubycon ZA / ZLG 16V 470uF
• Remove Q605 & Q606 and replace with a LME49720HA or Burson dual
• Short out R613, R614, R61 & R616
• Remove R651, R652, R653 & R654
• Remove the muting transistors
• Remove R617 & R618 and wire from this point direct to the output socket
• Change the signal capacitors around the opamp with something like a polystyrene cap

 

 

DAC

 

Fitting regs to each of the voltage feeds to the dac isolates each of the rails from each other and the rest of the noisy circuit. This allows the dac chip to perform better.

• Remove CD15 & CD16 and replace with something like a Rubycon ZA / ZLG 16V 470uF
• Remove CD04 & CD07 and replace with something like a Oscon SEPC 6.3V 470uF
• Remove UD200 and replace with low noise regulator like the Fidelity Audio SPower reg +5V - this feeds the Dac analogue
• Remove RD01 & RD04 and replace with low noise regulators like the Fidelity Audio SPower regs - dac digital
• Remove XD01 oscillator + RD02, CD02 & CD03 and replace with a quality low jitter clock like the Fidelity Audio C2 Premium clock 16.934Mhz. - Connect to XT1 of the dac.

Clock psu

 

Adding a dedicated psu for the clock (like the Fidelity Audio Ultra or Lite) helps the clock perform better + isolates the clock from the rest of the circuit lowering noise.

 

 

 

Decoder

 

• Remove C510 & C511 and replace with something like a Oscon SEPC 6.3V 470uF
• Remove R508 & R510 and replace with low noise regulators like the Fidelity Audio SPower regs - Decoder digital
• Lift C521 at the dac side and attach a 16.934Mhz clock feed from the dac clock using a buffered output - this clocks the decoder direct

 

There is a small alteration to the circuit that need sorting as Marantz made a mistake - This can be viewed on this page under decoder ic mod - http://www.fidelityaudio.co.uk/brents63.html

 

 

 

Servo

 

• Remove C120 & C122 and replace with something like a Oscon SEPC 6.3V 470uF
• Remove R122 & R123 and replace with low noise regulators like the Fidelity Audio SPower regs - Servo digital
• Remove X101 oscillator & R126 and replace with a quality low jitter clock like the Fidelity Audio C2 Premium clock 8.46Mhz. - Connect to XTL1 of the decoder.

 

RF

• Remove C504 and replace with something like a Oscon SEPC 6.3V 470uF
• Remove R505 and replace with low noise regulators like the Fidelity Audio SPower reg

 

HF

• Remove R107 and replace with low noise regulators like the Fidelity Audio SPower reg
• Fit a capacitor like a Oscon SEPC 6.3V 470uF on the output of the regulator

 

Note

 

There are many more upgrades to do to these great players but these upgrades lift the player hugely.

 

Of course you can see whats achievable here -http://www.fidelityaudio.co.uk/brents63.html