the only advantage for Brent in having a CD67, is that there is more room for more / bigger transformers
rowemeister said:Yes when he walks up to you naked and covered in lube
Wearing nothing but an affection for Diana Krall.
Re. the compo, I wonder if I cam claim my hearing, and therefore hobby, has suffered as a result of my assault... 
rowemeister said:
Ah well, I'll change that frame transformer VERY soon, for an internal toroid (clock supplies).
Hi Mauromauropenasa said:
Just finished the 330pF mod and know what ?? 😀 😀 😀 GRIN
Everything came into place and I can hear music again.
Thank you for your excelent work. !!!
Now I need a little more pace.... Maybe a clock on the servo ?
Regards
Ricardo
Mauro's mod
Is Mauro's mod intended to be done instead of the Bessel filter mods or as well as?
JIm
Is Mauro's mod intended to be done instead of the Bessel filter mods or as well as?
JIm
RCruz said:
Or save a few $$$ use a divide-by-2 pcb on the servo. Connect this to your current clock and it divides the 16.9MHz by 2 down to 8.46MHz. A dedicated clock is a little bit better but its also alot more expensive.
Brent
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