 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
In Reply to: Re: Help needed: finding (bridge) rectifier in DVD player (Panasonic RP56) posted by el TJ on February 16, 2003 at 12:22:12:
I noticed that my digital cable box (scientific atlanta 3200) was more detailed, pleasing than the sound from the RP56 dvd player. I've always thought that the RP56 picture was very good.I was looking to cleanup some of the harshness and lack of detail. I am very pleased by the results that this mod produced.
And yes, it worked. (Thanks to Monolith for the help in getting the recipe for the bridge rectifier). All this from changing the 4-pin stock rectifier to using 4 Fairchild diodes to form a bridge.
Much more detail (esp. noticeable in higher frequencies, but I think its all around) and smoother. To boot, the picture appeared more detailed too.
In summary:
Complexity:
Moderate. I would say basic electronics and soldering skills are required. The truly hard part, the research part is done in this forum!
Requires:
i)retrofitting 4 diodes in place of much smaller stock device, and
ii) how to take apart rp56 (see post from csown, "Adding SP/DIF to RP56").Risk:
Like all mods, Player could be damaged if you're not careful.Payoff: IMHO, well worth it!
Follow Ups:
I received mine as Engineering samples from Fairchild Semi.
Been looking for a source for these, and can't find them in stock. Where'd you get yours? Thx.
Maybe this is a dumb question, but doesn't TOSLINK run on TTL and coax is supposed to be 0-0.7V? Did you run the signal to an op-amp or some kind of driver circuit?
Hi,The signal for going into the toslink on my RP56 runs at 3V. Many receiver chips will take a variety of voltages; the cirrus chips in my DAC can take -12V to 12V, no problem for TTL. This kind of versatility is required for the various signals that DACs might be receiving nowadays. For example, lots of soundcards use S/Pdif @ TTL voltages (I guess they're too cheap to stick in a divider).
best,
-Chris
Interesting. I guess what I'm worried about more than the voltage, is the ability of whatever is supplying that signal to be able to drive a coax cable. Also, you will have some problem with impedance characteristics of the RP56's circuit vs. a 75 ohm connector.Anyway, I'm trying this mod, and I soldered togeter a voltage divider that will come out at about 75 ohm impedance. It uses a 100 nF cap, two resistors, and some inverters to drive the output. I'll let you know how it works....
TJ
I just used Chris' post to find out how to take apart the RP56 to get at the main board. As I don't have a digital preamp, I haven't tried the SP/DIF mod itself.
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
