Glenn2 said:
Something I have been meaning to do for some time ! (I am still waiting for my LM6171 samples.)
The LM6171 should be superior at the DAC output as it is one of the few fully symmetrical opamps. It is also important that the associated resistors and caps are as close a tolerance as possible (eg. 0.1% resistors RD21-28, R601-4). This will result in optimum residual noise from the DAC.
This has been mentioned before in the thread but I do not think it has been tried. The OPA627 has been biased into class A in other applications so it does work. Go ahead and try it. I would be interested in the results.
Andy
adfinni said:
To each his own ... but why build a seperate power supply when you can gain much more by isolating the transport and the DAC? My personal opinion is that if you are going to the trouble of making an external power supply, why not just build a transport and a DAC and be done with it instead of isolating the P/S from the Marantz when you still have an attached DAC that can suffer from transport vibration?
Not intending to offend anyone ... just an observation ...
HAHA banter at simons expense.
Brent, don't suppose i could have your msn for some killing updates and general picking your brains 😀
Brent, don't suppose i could have your msn for some killing updates and general picking your brains 😀
While waiting for the rest of my components to arrive, I have been reading vociferously and came across this Italian Page, rather like Ray's, with pccies (Good for dummies like me).
http://www.geocities.com/SoHo/3379/audiogarage/CD67viso.html
One thing I found surpirsing was blu-tack on the IC's, where you have all used copper shields...?? I guess they don't need a ground, but do they REALLY offer any shielding ...?
😕
k.
http://www.geocities.com/SoHo/3379/audiogarage/CD67viso.html
One thing I found surpirsing was blu-tack on the IC's, where you have all used copper shields...?? I guess they don't need a ground, but do they REALLY offer any shielding ...?
😕
k.
craigtone said:
Not to mention digital noise from Dac and control processor on the same earth as analogue.
allan
jksmurf said:
Lol at his LED mod.
Thats how its done 😀
An externally hosted image should be here but it was not working when we last tested it.
Brent 😀
Pretty blue light is all the more reason to leave the cover off - that besides admiring ones modifications.
I imagine copper foil shieds on the chips makes OK dampening if not quite Blu-tac excellence! I noticed also he left his power rail fuses in place unlike me.
Anyone here volunteer to try Blu-tac? Or Bybee clarifiers? I worry what could happen if North Korea gets hold of such technology, Elvis hair is dangerous enough!
I imagine copper foil shieds on the chips makes OK dampening if not quite Blu-tac excellence! I noticed also he left his power rail fuses in place unlike me.
Anyone here volunteer to try Blu-tac? Or Bybee clarifiers? I worry what could happen if North Korea gets hold of such technology, Elvis hair is dangerous enough!
craigtone said:
No offence taken. As long as the sound is superb I'm not concerned with "ideal". A budget player that performs to high end standards, and done with limited electronics knowledge. That's what my player is all about! 😀
An update - I have a whistling noise, but the sound is just fantastic now: warm, MASSIVE bass, organic sounding, great character in voices, finally not really like digital at all.
markk02474 said:
Ive modified mine as much as I can go. No room left and the blue leds were a whim.
The copper or alu on the chips is for rf shielding not damping.
Brent
SimontY said:
HI Simon,
Have you seen a Doctor ??
Is it coming from the CD mechanism ? If so, this was a common fault with early cdm12 mechs. The later ones were modded with a heavier centre weight. Solution is to fit a new later mech or glue a coin (something worth very little like a 1 euro coin) in the centre.
Andy
poynton said:
Ba-boom! 😉
Hi Andy,
It's coming from the analogue output. If you turn it up loud it's a whining, sounds like it's mostly at about 2khz. But there is other noise and harmonics, so it sounds rather like a whistle. I'd like to fix it because it's just about loud enough to occasionally impinge on the music, however subtly. The overall objective noise level has been increased.
Simon
craigtone said:
Hi.
As noted by Simon, the idea of this thread is to improve the CD63/67 not to build the ideal cd player.
Building an external power supply is a fairly straightforward proposition whereas designing and building a separate DAC etc. is not! (see the many threads on this forum !)
One source of noise is the display circuitry. Little has been suggested to improve matters here except for switching it off! The associated control uP also puts out vast amounts of garbage.
Transport vibration has little affect on the DAC compared with other interferance sources. It should not vibrate in any case! Damping can (has) be applied to the transport and also to the individual chips. See recent posts in this thread for blutack damping.
Separating the DAC from the transport also introduces its own problems e.g. what interface, jitter, reclocking etc....
I'll stick to improving my '63, thanks.
Andy
Broken track between r608 and L602. I resoldered evrything an still nothing. But then i looked at the solder at the track joint on r608 and i noticed a straight edge 😕 
broken track. Soldered a little wire jumper, and after reassembly the right headphone driver came to life.
I finished at 12:30am and spent the next hour and a half listening to music 😀
Im cleaning up the other solder joints today, will install my clock and PSU later, and may even have a go at putting on the 5V reg board. Il sort the reg board if i can catch simon on msn for some harrasement.
Thanks for narrowing down the problem for me guys, helpful as ever. But im unsure how the track broke and buckled. Must have been too much heat from my iron when de-soldering.
broken track. Soldered a little wire jumper, and after reassembly the right headphone driver came to life.I finished at 12:30am and spent the next hour and a half listening to music 😀
Im cleaning up the other solder joints today, will install my clock and PSU later, and may even have a go at putting on the 5V reg board. Il sort the reg board if i can catch simon on msn for some harrasement.
Thanks for narrowing down the problem for me guys, helpful as ever. But im unsure how the track broke and buckled. Must have been too much heat from my iron when de-soldering.
Excellent. Yes it was too much heat that caused it.
Remember when fitting your clock to remove the 2 ceramics and the 1meg resistor
Brent
Remember when fitting your clock to remove the 2 ceramics and the 1meg resistor
Brent