Re: Marantz cd 53 mods
No, it's not 0V, there's a DC offset. It's about 6V IIRC, that's why the output cap is necessary. The 100u is a practical value, the minimum is much lower, depends a bit on the load impedance the player's connected to, you know: C = 1/(2*pi*F*R). 3u3 seems a bare minimum at R=10k.
I'm glad it worked! If you'd like to swap opamps, use an IC socket, a good one with turned contacts will do fine.
Most of these components are SMD. It's very hard to find a proper replacement for those, due to their size. The choices are limited. So in most cases, the author (as in 'me'), just left them in.
Regards,
Ray
avr300 said:
No, it's not 0V, there's a DC offset. It's about 6V IIRC, that's why the output cap is necessary. The 100u is a practical value, the minimum is much lower, depends a bit on the load impedance the player's connected to, you know: C = 1/(2*pi*F*R). 3u3 seems a bare minimum at R=10k.
RCruz said:
I'm glad it worked! If you'd like to swap opamps, use an IC socket, a good one with turned contacts will do fine.
fossil2k said:
Most of these components are SMD. It's very hard to find a proper replacement for those, due to their size. The choices are limited. So in most cases, the author (as in 'me'), just left them in.
Regards,
Ray
SimontY said:
Hmm, I only have 15 left! I've modded quite a few players and sold them on though, helped out a bit whilst I was out of work.
I am in the middle of a re-work of my CD67 at the mo. I have added 30va 2x9v for the 5v digital & analogue and have mounted the regs on the board to try and avoid the need for a cap on the output pin of the reg. I will then build my monster off-board psu for the opamps.
Lee.
225VA against 80VA transformer
Hi there!
After swapping out an internal 6VA tranny for an external 225VA I reported a great deal of improvement in the bass and mid range areas for my CD63 running 8620 opamps. I then replaced the 225VA for an 80VA. Having done this, the lower bass seemed a little light, but mid range improved again! I then placed the 225VA casually onto the CD player, ready to take it back to my work room. Hay presto, bass is back, but the mid range is back as it was with the 225VA connected. I found that by placing a weight on the rack (not on the CD player) I gained the same results. Now i need to find out how to sharpen the mid while gaining the lower bass. Any ideas?
Cheers,
Geoff
Hi there!
After swapping out an internal 6VA tranny for an external 225VA I reported a great deal of improvement in the bass and mid range areas for my CD63 running 8620 opamps. I then replaced the 225VA for an 80VA. Having done this, the lower bass seemed a little light, but mid range improved again! I then placed the 225VA casually onto the CD player, ready to take it back to my work room. Hay presto, bass is back, but the mid range is back as it was with the 225VA connected. I found that by placing a weight on the rack (not on the CD player) I gained the same results. Now i need to find out how to sharpen the mid while gaining the lower bass. Any ideas?
Cheers,
Geoff
6h5c said:
And therefore with a voltage swing at 2V max, the cap will still be "most positive" at fet end, therefore it doesn't have to be nonpolar. Great - it opens up the possibilities.
edit: Where have I seen that it should be nonpolar. Your fine PDF shows a polar C5. Forget I asked.
Yes, with 47k load, you can go as low as 1u and still be way low enough at -3db.
avr300 said:And therefore with a voltage swing at 2V max, the cap will still be "most positive" at fet end, therefore it doesn't have to be nonpolar. Great - it opens up the possibilities.
edit: Where have I seen that it should be nonpolar. Your fine PDF shows a polar C5. Forget I asked.
Yes, with 47k load, you can go as low as 1u and still be way low enough at -3db.
Ah, most autodidactive!
Indeed both can be used of course, although film caps generally have better quality. There's also the phase shift that should be considered, around the -3dB point it will be considerable (45 deg.). So to keep the shift in the low range acceptable, I usually use a cap 10x bigger than calculated.
Regards,
Ray
rowemeister said:
Thank you very much. It was good to finally meet one of you who has contributed much valuable info/help to this thread. Nice bloke too, btw.
I'll be fitting the S-Power on my dac analogue tomorrow morning. Where do you reckon I should stick the Invisus that is presently there? (polite answers only please!)
Cheers,
Lee.
Re: Re: Marantz cd 53 mods
Hi Ray
As I am not using the Phonos amp and I already removed the analog output transistors, can I cut the following links ?
U262 (has a bypass under ?! what for ?)
U211 - RMUT into phones
U207 - LMUT into phones
U220 - LMUT
U222 - RMUT
Also, as the CD53SE does not have a optical digital output, (CT10 and RT10 and the socket inexistent), can I remove U221 (Digital Psu to optical out) ?
Should I decouple any lines after cutting the Uxxx ?
Regards
Ricardo
6h5c said:
Hi Ray
As I am not using the Phonos amp and I already removed the analog output transistors, can I cut the following links ?
U262 (has a bypass under ?! what for ?)
U211 - RMUT into phones
U207 - LMUT into phones
U220 - LMUT
U222 - RMUT
Also, as the CD53SE does not have a optical digital output, (CT10 and RT10 and the socket inexistent), can I remove U221 (Digital Psu to optical out) ?
Should I decouple any lines after cutting the Uxxx ?
Regards
Ricardo
