I just picked up a minty CDB-630 for $25. Many lists show it with a TDA1541, but it actually has the A version, made in '89. The transport, especially the gear that seems to wear out, is in great shape. The circuit board is the simple Philips/Marantz variety common to many units. I'd like to mod the DAC to make it unfiltered zero oversampling. I know some of you will recommend I keep a filter on it, but I'm want to go the minimalist 47 labs route.
I've been doing some searching, and have found a few methods and a bunch of outdated links. I've seen the mod where you cut a few traces and make some jumpers. I've heard about mods where you remove the 7220 chip, bend some leads, bridge some others, and put it back. I've heard folks mention removing the 7220 all together.
What is the best method? I have done some soldering (built a chip amp) etc, but working with little traces worries me a bit. I don't have a soldering station, and I destroyed my Sonic Impact. I think I can pull most anything off, but easier is better. Cheaper is good to. Also, I've downloaded the Marantz CD50 service manual, which I believe shares the same board. I do understand schematics a bit, but I am by no means fluent in circuits.
I'm planning to replace the 'lytics with something better. I'm also looking at replacing the decoupling caps on the DAC. Any recommendations for cost effective parts? I'll get 'em from digikey, as they're pretty local for me.
Are there any other mods I should do right away? I'm looking for bang for the buck right now. I may decide to go crazy with a fancy power supply or boutique parts down the road, but for now I'd like to focus on making it work NOS and doing the mods necessary to get a good result.
thanks,
pj
I've been doing some searching, and have found a few methods and a bunch of outdated links. I've seen the mod where you cut a few traces and make some jumpers. I've heard about mods where you remove the 7220 chip, bend some leads, bridge some others, and put it back. I've heard folks mention removing the 7220 all together.
What is the best method? I have done some soldering (built a chip amp) etc, but working with little traces worries me a bit. I don't have a soldering station, and I destroyed my Sonic Impact. I think I can pull most anything off, but easier is better. Cheaper is good to. Also, I've downloaded the Marantz CD50 service manual, which I believe shares the same board. I do understand schematics a bit, but I am by no means fluent in circuits.
I'm planning to replace the 'lytics with something better. I'm also looking at replacing the decoupling caps on the DAC. Any recommendations for cost effective parts? I'll get 'em from digikey, as they're pretty local for me.
Are there any other mods I should do right away? I'm looking for bang for the buck right now. I may decide to go crazy with a fancy power supply or boutique parts down the road, but for now I'd like to focus on making it work NOS and doing the mods necessary to get a good result.
thanks,
pj
I forgot to mention, I'm also thinking of replacing the LM833N's. Opinions on the best replacements seem numerous. How about OPA2134's? I've got them in my phono pre (Hagerman Bugle) and they seem to have a great cost/performance ratio. I know, I've rolled a ton of questions into this thread. There are so many opinions and I ideas that I need some help to sort them out.
pj
pj
Look at this thread: http://www.diyaudio.com/forums/showthread.php?s=&threadid=87870&highlight=
I was hesitant to drill holes in the board, but I as I think about it, it seems easier than completely removing (bending pins, then replacing) the 7220.
Will replacing all of those 'lytics really make decent difference? I know some folks do it as standard practice. If I do, what are the best value parts to use?
pj
Will replacing all of those 'lytics really make decent difference? I know some folks do it as standard practice. If I do, what are the best value parts to use?
pj
"Mute mod"
Could someone please, explain what does "mute mod" actually do? I understand it means making bypass from pin23 of SAA7220 to pin11 of SAA 7210. It is often mentioned with nonos, like here:http://www.diyaudio.com/forums/showthread.php?postid=1024653#post1024653
Could someone please, explain what does "mute mod" actually do? I understand it means making bypass from pin23 of SAA7220 to pin11 of SAA 7210. It is often mentioned with nonos, like here:http://www.diyaudio.com/forums/showthread.php?postid=1024653#post1024653
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