Re: Mauro's mod
No, the 330 pF caps must be installed in the original filter.
And the results is very different from bessel filter, as Mauro did explained above.
Ricardo: it's old, but now you could make this tweak (imho).
http://www.acoustica.org.uk/
Solder the clock on patterns side, and solder the metal can of XO to ground plane.
And put a separate regulator in place of cd04+ for XO.
You could use a lm317, for 5V, with in series output a 10 ohm resistor.
Common soldered on pcb gnd plane.
Ciao
jimh0612 said:
No, the 330 pF caps must be installed in the original filter.
And the results is very different from bessel filter, as Mauro did explained above.
Ricardo: it's old, but now you could make this tweak (imho).
http://www.acoustica.org.uk/
Solder the clock on patterns side, and solder the metal can of XO to ground plane.
And put a separate regulator in place of cd04+ for XO.
You could use a lm317, for 5V, with in series output a 10 ohm resistor.
Common soldered on pcb gnd plane.
Ciao
RCruz said:
That will tighten things up nicely and give immense detail. Brent's product (Servo clock - 8.46Mhz) works well for me and is the only ready-made option at the price I know of:
http://www.audioupgrades.co.uk/clocks.shtml
I can vouch for Brent's products too. They offer fantastic performance and value for money.
Pic of clock on another cd67 with discrete on the main-board for anyone who's interested.
Lee.
Pic of clock on another cd67 with discrete on the main-board for anyone who's interested.
An externally hosted image should be here but it was not working when we last tested it.
Lee.
Re: Re: Mauro's mod
I believe this is the best option... I will be talking to you latter by e-mail.
Thank you Riccardo.. I already have been studiyng this mod but it seems very complicated to me (it involves messing with very sensitive parts and very small ones "SMD".... I am not that good and I can not afford to mess up)
But before I go any of these ways I need a very important advise:
I did the Mauro´s mod with 330pF Polystyrenes.
At the same time (because the modded CD53 is now a bit hard to open "dismantle" any time I need to do a new mod), I replaced the stock ceramic filter caps with 1% silver micas keeping the exact values:
CD21 22 23 24 120p Silver Mica
C601 602 603 604 120p Silver Mica
C607 608 100p Silver Mica
And finally I replaced the opamp output resistors from 47k carbon to a 47k welwin metal film.
The gains in imagery, stage width, instrument defenition and female voice credibility where substantial.
Finally the player seems to be able to play tunes like a normal turntable but I notice a big annoying difference that is always inducing me to lower the volume:
After this mod, I got an annoying presence in the medium to high frequencies so that if a singer shouts, the sound becomes too screetchy.
The voices and instruments are very well defined, articulated and perfectly placed in the stereo picture but I also get this proeminence in the high frequencies that makes string guittars (Steve Vay) to be too nasty and screaming voices (Led Zeppelin) to be almost unbearable.
I would like your comments on the possible causes:
The micas in the filter ?
The metal film resistor in the output of the LM4562NA ?
Or is this due to the better performance now obtained from the opamps ?
Best regards
Ricardo
Thank you Brentrowemeister said:
I believe this is the best option... I will be talking to you latter by e-mail.
riccardo said:
Thank you Riccardo.. I already have been studiyng this mod but it seems very complicated to me (it involves messing with very sensitive parts and very small ones "SMD".... I am not that good and I can not afford to mess up)
But before I go any of these ways I need a very important advise:
I did the Mauro´s mod with 330pF Polystyrenes.
At the same time (because the modded CD53 is now a bit hard to open "dismantle" any time I need to do a new mod), I replaced the stock ceramic filter caps with 1% silver micas keeping the exact values:
CD21 22 23 24 120p Silver Mica
C601 602 603 604 120p Silver Mica
C607 608 100p Silver Mica
And finally I replaced the opamp output resistors from 47k carbon to a 47k welwin metal film.
The gains in imagery, stage width, instrument defenition and female voice credibility where substantial.
Finally the player seems to be able to play tunes like a normal turntable but I notice a big annoying difference that is always inducing me to lower the volume:
After this mod, I got an annoying presence in the medium to high frequencies so that if a singer shouts, the sound becomes too screetchy.
The voices and instruments are very well defined, articulated and perfectly placed in the stereo picture but I also get this proeminence in the high frequencies that makes string guittars (Steve Vay) to be too nasty and screaming voices (Led Zeppelin) to be almost unbearable.
I would like your comments on the possible causes:
The micas in the filter ?
The metal film resistor in the output of the LM4562NA ?
Or is this due to the better performance now obtained from the opamps ?
Best regards
Ricardo