bpribadi 0 Report post Posted September 14, 2004 (edited) the CD player doesn't ground to earth. Is it ok if i ground the chasis to earth? Not necessary (I prefer not). The important thing is to ground the chasis to the audio ground. Another simple improvement is to put small caps (22 nF - 100 nF) on the bridge diode, it will also smoothen the bridge DC output from AC transition. Example to put the small cap on the PS bridge from my 'failed' project layout: Edited September 14, 2004 by bpribadi Share this post Link to post Share on other sites
huangyong 0 Report post Posted September 16, 2004 A Chinese DIYer advised me not to use the internal Rf. but use an external resistoras Rf. any difference? Share this post Link to post Share on other sites
huangyong 0 Report post Posted September 16, 2004 (edited) pic\ Edited September 16, 2004 by huangyong Share this post Link to post Share on other sites
bpribadi 0 Report post Posted September 16, 2004 A Chinese DIYer advised me not to use the internal Rf. but use an external resistoras Rf. any difference? Yeap, that is also a good approach, then you can fine tune the Rf value. The small cap on the Rf also will function as a mild low pass as well. What's the progress so far? Share this post Link to post Share on other sites
huangyong 0 Report post Posted September 16, 2004 Still stuck at PSU stage. I still need some parts for the I/V converter. Will get them this Sat. Share this post Link to post Share on other sites
huangyong 0 Report post Posted September 21, 2004 ooh... accidentally shorted the rulator board...it smokes ( real smoke ) and i already removed all the resistors and caps around PCM61P (DAC), preparing to put in the new I/V converter....but without PSU, it wont work... I was panic.... i had no choice but tried to fix it. I put everything back followed the schematic in the datasheet. ( which clean up the original signal path ) When i turned it ON...wow.... great improvement.. very very musical ... now i m stastified with the internal I/V converter. now my next mod it to change the output RC filter. Share this post Link to post Share on other sites
huangyong 0 Report post Posted September 21, 2004 Original circuit. Share this post Link to post Share on other sites
huangyong 0 Report post Posted September 21, 2004 i short the 820ohm resistor, remove the 47Kohm resistor and 5.6nF cap. i m not sure whether to remove the 68pF cap or not. pls give advice. Share this post Link to post Share on other sites
huangyong 0 Report post Posted October 8, 2004 Finally, i got a camera to take these pics. Overall Headphone Out DAC (PCM61p) Power Supply Share this post Link to post Share on other sites
huangyong 0 Report post Posted October 8, 2004 Bird View Share this post Link to post Share on other sites
digi01 0 Report post Posted October 8, 2004 wonderful! so many quality caps Share this post Link to post Share on other sites
bpribadi 0 Report post Posted October 8, 2004 Aaahhh that's better,... I like pics I think you can remove the 68pF, looks like it is to suppress high frequency oscillation. If you have enough small caps close to the 627, I think it should be stable Share this post Link to post Share on other sites
huangyong 0 Report post Posted October 8, 2004 Aaahhh that's better,... I like pics I think you can remove the 68pF, looks like it is to suppress high frequency oscillation. If you have enough small caps close to the 627, I think it should be stable I removed that liao.. Share this post Link to post Share on other sites
variablefeedback 0 Report post Posted December 18, 2004 you are lucky, mine cdp uses all dual channel opamps. Denon DCD-2880AR review / modification Share this post Link to post Share on other sites
huangyong 0 Report post Posted December 20, 2004 you are lucky, mine cdp uses all dual channel opamps. Denon DCD-2880AR review / modification you are luckier to have such a nice cd player............ Share this post Link to post Share on other sites
