With this article fresh in mind does anyone have any opinions on the usefulness of making the ground line on the regulator boards extra thick? I assume the lower the resistance the less the problem. I could add a copper wire along all of it and solder it all up with lots of solder, reducing the "parasitic resistance" of the ground paths to something very low. That should reduce the noise.
poynton said:
Ahha, thanks for doing it. Page 3 was hard to read but doable! For future reference I would recommend scanning at 300dpi, in mono, then inserting each page into a DTP program like Publisher, then converting it into PDF format. This will make a small file with very good readibility when printed.
Simon
Hi Poynton,
that article confirms the transformer centre tap to audio ground and smoothing caps 0v wired to audio ground. Nice to hear that someone else has seen the light 14 years before me!
Note, that the audio ground is NOT mounted on the joint between the smoothing caps of the dual polarity supply. This is really important.
How about starting a Wiki describing the process in detail?
that article confirms the transformer centre tap to audio ground and smoothing caps 0v wired to audio ground. Nice to hear that someone else has seen the light 14 years before me!
Note, that the audio ground is NOT mounted on the joint between the smoothing caps of the dual polarity supply. This is really important.
am I supposed to remember this?
How about starting a Wiki describing the process in detail?
AndrewT said:
OT, but I'd like to know more about this. In my power amp I have the centre point between the smoothing caps (split supply) as the star. Am I wrong to do this then??
lol. Don't know how to do that. I'll look into it later if it seems useful to people.
Simon (off for a workout then soldering BGs or grounds then beers)
Hi Simon,
post 4589,
the caps before the regs and the reg 0v should each have their own grounding connections. That applies to ALL the regs including the 3 at the bottom.
It's all down to seeing that the rectifier and following smoothing caps are part of the charging circuit and that they need their own return loops to keep the buzzing out of the clean stages.
It helps if the smoothing caps and the rectifiers are kept in close proximity and with a very low loop area in the flow and return wires.
Similarly the transformer to rectifier cabling should also have a small loop area for the flow and return wires.
Is the cdp in it's own metal case? If so then the "E" should have a permanent connection to chassis. Again the RCAs should be isolated from chassis.
I see a note beside the 6r8. If you really want to experiment then add a switch in parallel to the disconnecting networks. This is often called an earth lift switch in commercial gear. I do not recommend you leave the switch closed. But feel free to experiment with it. Leaving two earth lift switches closed (whether in sources or pre-amp or power-amp) will create a hum loop and you will hear it. TRY IT and tell us.
post 4589,
the caps before the regs and the reg 0v should each have their own grounding connections. That applies to ALL the regs including the 3 at the bottom.
It's all down to seeing that the rectifier and following smoothing caps are part of the charging circuit and that they need their own return loops to keep the buzzing out of the clean stages.
It helps if the smoothing caps and the rectifiers are kept in close proximity and with a very low loop area in the flow and return wires.
Similarly the transformer to rectifier cabling should also have a small loop area for the flow and return wires.
Is the cdp in it's own metal case? If so then the "E" should have a permanent connection to chassis. Again the RCAs should be isolated from chassis.
I see a note beside the 6r8. If you really want to experiment then add a switch in parallel to the disconnecting networks. This is often called an earth lift switch in commercial gear. I do not recommend you leave the switch closed. But feel free to experiment with it. Leaving two earth lift switches closed (whether in sources or pre-amp or power-amp) will create a hum loop and you will hear it. TRY IT and tell us.
Guys,
I've opened a new threat (sorry Simon I've quoted you and they do not agree...)
http://www.diyaudio.com/forums/showthread.php?s=&threadid=89590
I've enjoyed some discs, and now I'm almost sure that it sounds not better or worst, but diffrent:
On this heavy rock, White Zombie "Astro Creep 2000" used to sound as Nuclear Assault's records: because of mess and boomy bass it felt powerfull and dense. Now White Zombie sounds more clear, and some feeling of power has gone, even if all the instruments has appeared more clearly. I just need to be used too, but the pleasure is really there!
I'm also using some left parts (Farnell has some minimum quantity when order a part) to upgrade the PS of my Sansui tuner, and then what's left will be sold as a pack on eBay. Many things like Elna RJH, Rubycon ZLH...
I've opened a new threat (sorry Simon I've quoted you and they do not agree...)
http://www.diyaudio.com/forums/showthread.php?s=&threadid=89590
I've enjoyed some discs, and now I'm almost sure that it sounds not better or worst, but diffrent:
On this heavy rock, White Zombie "Astro Creep 2000" used to sound as Nuclear Assault's records: because of mess and boomy bass it felt powerfull and dense. Now White Zombie sounds more clear, and some feeling of power has gone, even if all the instruments has appeared more clearly. I just need to be used too, but the pleasure is really there!
I'm also using some left parts (Farnell has some minimum quantity when order a part) to upgrade the PS of my Sansui tuner, and then what's left will be sold as a pack on eBay. Many things like Elna RJH, Rubycon ZLH...
SimontY said:
Simon, The best ground wire you can possibly use is a flat braid as the main earth, usually you can achieve this by striping the outer braid of some RG58 coax for instance, slide a sleeve over it for electrical protection, and take it to your prefered earth. The resistance may look the same, however, to RF & noise, the resistance and inductance is a little better.
For strip board, you may fancy "weaving" along one strip so a wire is present on the top of the board, say spaced 3 holes apart, you then have access to the ground wire on both sides if its usefull. Comes in handy when experimenting.
If you are carefull, and neat enough you can also make a ground plane on top of strip board with the stick on copper sheild, just pop a neat hole sufficient in size so as not to short anything out for component legs, alternativly, just "wack" some ground strips in blank places if there is any room. Experiment as sometimes any extra capacitance may have undesired effects.
Im trying some more mods to day (soldering iron willing!) and maybe post some pics as i havnt shown any yet lol.
Thanks for the tips! I might have a go with that super ground wire at some point, but I'm not going to redo all the old ones.
I did a little unplugging last night and it seems my hum is coming from within the power amp itself, mainly. The cd player's noise could do with being reduced though.
Sounding good though
Simon
I did a little unplugging last night and it seems my hum is coming from within the power amp itself, mainly. The cd player's noise could do with being reduced though.
Sounding good though
Simon
Hey afterall Ray got me working!
Look how much things he made me change!
Look how much things he made me change!
An externally hosted image should be here but it was not working when we last tested it.
Well im off to see we are scientists tonight at rock city, which is something even the best modded 63 can't reproduce off the cd. Then fireworks at a massive houseparty.
Il try and post when i get back in a horrific state
Lol dennis, watch out for flying caps lads and........
Il try and post when i get back in a horrific state
Lol dennis, watch out for flying caps lads and........
An externally hosted image should be here but it was not working when we last tested it.
Nice.
I did some more work today....
1 - removed grounds from each wire that feeds the reg boards from the external psu
2 - soldered a thick wire from the external psu ground star to the cd player's ground star
3 - added a disconnecting network of 8.2R and 22nF (in parallel) in line with the star to safety earth in the external psu
4 - cut the ground on each main reg board before the reg and made another return to a mini star point on the reg boards
5 - soldered good ground wires from each reg board to the cdp star
So, to clarify, there's now one "master" ground connection, which is the only ground wire between the cdp and external psu.
Objectively, noise appears to have reduced a little, although there is still a slight squeal and some broadband noise. There is hum, which seems to be a power amp problem (no difference with cdp connected or not).
Subjectively, the music sounds fantastic. Even more dynamic with a lower noise floor.
Black Gates to go in soon!
Simon
I did some more work today....
1 - removed grounds from each wire that feeds the reg boards from the external psu
2 - soldered a thick wire from the external psu ground star to the cd player's ground star
3 - added a disconnecting network of 8.2R and 22nF (in parallel) in line with the star to safety earth in the external psu
4 - cut the ground on each main reg board before the reg and made another return to a mini star point on the reg boards
5 - soldered good ground wires from each reg board to the cdp star
So, to clarify, there's now one "master" ground connection, which is the only ground wire between the cdp and external psu.
Objectively, noise appears to have reduced a little, although there is still a slight squeal and some broadband noise. There is hum, which seems to be a power amp problem (no difference with cdp connected or not).
Subjectively, the music sounds fantastic. Even more dynamic with a lower noise floor.
Black Gates to go in soon!
Simon
R149, R150, R164, R165 missing
Hi,
I've a CD63SE giving an Err02 error intermittently.
Opened up the player, but R149, R150, R164, R165 are missing from the main PCB and has been replaced by wire "bridges". I've compared it to a CD53 and all the mentioned resistors are indeed in place.
Is this normal on a CD63SE model not to have these resistors populated? What would the reasoning be behind such a mod?
Sorry I'm a bit of a noob with this ...
Thanks,
Johan
Hi,
I've a CD63SE giving an Err02 error intermittently.
Opened up the player, but R149, R150, R164, R165 are missing from the main PCB and has been replaced by wire "bridges". I've compared it to a CD53 and all the mentioned resistors are indeed in place.
Is this normal on a CD63SE model not to have these resistors populated? What would the reasoning be behind such a mod?
Sorry I'm a bit of a noob with this ...
Thanks,
Johan
