johnm said:Kevin what digital output resistor combo are you currently using, and what is considered to be the 'industry standard'?
To sum up my gear, I'm using a 75ohm coax cable, terminated with 75 ohm BNC plugs on each end. The sending and receiving equipment will also have BNC sockets.
I'm currently thinking of using 390 / 91 ohm combo - does this sound about right?
Thanks,
- John.
P.S. I take it all back... that Citizen crystal is GREAT! Yep, couldn't resist the urge to try it again. This time - now the Black Gates have had over a week to settle - it sounds much better
Hi John,
I'm using 402 (would prefer 392, but could not get that value from Michael Percy) and 100//1.31K to get 93 ohms. This gives me near to a 75 ohm termination, and acceptable amplitude with a 5V source. I'm happy with the combo as it does not violate any application requirements for spdif or this chip set. These values are considered relatively standard (but not universal) for 5V operation.. (Google though and you will see these values used in a lot of places.)
I ordered a bunch of additional parts today, I plan on going back to 1000uF (BG now) at the input to the board, and upgrading the 470uF in the output of the 5V supply. I would do it the way Peter has, but unfortunately due to the design of this board and my physical layout there is about 6" - 7" of Kimber TCSS wire between the supply and the board, and it definitely sounds better with a cap in this location. (Well I have convinced myself that that is the case..
)I also ordered 4 different 0.22uF caps for the critical tracking servo time constant cap. I will be careful with the stock cap.
One is a Rel RT, another is Rel PPFX, Solen, and a BG PK type. I will try them all unless one is so outstanding I know I am done..
Once I pin down the bass issue (the other mech seemed better in that regard, this one in others) I should be done with the electrical mods.
I'm prospecting for brass bar and will probably purchase 12" of 1.5" square bar which will get me about 6lbs of additional mass that will be mounted right near the mechanism on either side.
This thing sounds really good, and I believe it will just get better as I complete the last changes, and the caps all break in.
Tomorrow evening I should be able to spend several hours listening to it.
BrianGT said:wow, this is the most interesting thread that I have read in a long time. I was always curious about doing something like this, after playing around with the cdpro2.
I need to go see what I can find at Fry's tomorrow at lunch
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Brian
It's pretty amazing. Look for JVC RCEZ31, 32 or 51.. You might luck out.
A little work and you will have a real giant killer..
kevinkr said:
It's pretty amazing. Look for JVC RCEZ31, 32 or 51.. You might luck out.
A little work and you will have a real giant killer..
Thanks, will see what I can find tomorrow.
To be honest, I haven't see any projects on the forum lately that have made me want to go out and build something, but this sure does look interesting
Thanks for sharing all this info Peter!
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Brian
BrianGT said:
Thanks, will see what I can find tomorrow.
To be honest, I haven't see any projects on the forum lately that have made me want to go out and build something, but this sure does look interesting
Thanks for sharing all this info Peter!
Brian
This came along at just the right time for me, I was looking for an interesting project and needed an additional transport to free my sometimes fragile SCD-777ES from the task of playing CDs for non critical listening. (The ShigaClone is actually very suitable for extremely critical listening.) I had planned under protest to just buy a good used transport and tweak it, but this is much more fun, and probably much less expensive for the level of performance achieved.
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Hello All ,
after all the mods I went back to C906 ... yes . What a nice surprise . For me the best choice is the value 0.068u . No doubt . Actually using a foil capacitor , I feel here the value is more important than the quality of the cap ( just as a start ) and I also tried 0.22 .
The 0.068 C906 cap gives to the music a more organic ( way more ) representation with nice eq between the audio spectrum , air between the instruments ( in fast passages ) , and highs really smooth .Tempted to try with 10nF as Peter did in his mods , for now I stop here with that cap .
I appreciate also a lot the MUR diodes and the EI transformer that turns to be better over the toroidal IMHO .
Now just want to play a little with C918 and C930 .
after all the mods I went back to C906 ... yes . What a nice surprise . For me the best choice is the value 0.068u . No doubt . Actually using a foil capacitor , I feel here the value is more important than the quality of the cap ( just as a start ) and I also tried 0.22 .
The 0.068 C906 cap gives to the music a more organic ( way more ) representation with nice eq between the audio spectrum , air between the instruments ( in fast passages ) , and highs really smooth .Tempted to try with 10nF as Peter did in his mods , for now I stop here with that cap .
I appreciate also a lot the MUR diodes and the EI transformer that turns to be better over the toroidal IMHO .
Now just want to play a little with C918 and C930 .
All that I can find locally is the JVC RCEZ38. Would this work?
http://www.walmart.com/catalog/product.do?product_id=8827852
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Brian
http://www.walmart.com/catalog/product.do?product_id=8827852
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Brian
Re: shigaclone
just trace that trace from digi out pad to chip
as stated in pdf ( first several posts of thread ) PD drilled pcb and soldered wire much closer to chip , if not on exact pin ;
quan said:My Shigaclone died last night-the pad at digital out lifted after too amny times fiddling and also C906 postision after trying to remove the large Auricap.
WRT extracting direct digital output from the chip-Peter can you help? How to go about it?
just trace that trace from digi out pad to chip
as stated in pdf ( first several posts of thread ) PD drilled pcb and soldered wire much closer to chip , if not on exact pin ;
RCEZ32 Update
A couple of mysteries resolved:
Changing the value or removing C950 seems to change the sound for the worse.. I reinstalled the original 1000uF cap in this location, had not yet replaced C949 (470uF) and sure enough the sound reverted to the more controlled, tight bass, I thought I remembered, and an overall more relaxed sounding (less mechanical) presentation. I did this on both my mechanisms and the result was the same.
Edit:
C915 may not be the tracking cap, but I'm not sure and I'm too tired to figure it out tonight.
A couple of mysteries resolved:
Changing the value or removing C950 seems to change the sound for the worse.. I reinstalled the original 1000uF cap in this location, had not yet replaced C949 (470uF) and sure enough the sound reverted to the more controlled, tight bass, I thought I remembered, and an overall more relaxed sounding (less mechanical) presentation. I did this on both my mechanisms and the result was the same.
Edit:
C915 may not be the tracking cap, but I'm not sure and I'm too tired to figure it out tonight.
Re: shigaclone
As you can see in a datasheet here: http://pdf1.alldatasheet.com/datasheet-pdf/view/40975/SANYO/LC78601E.html the DOUT on LC78601 is pin 29. Pick the ground somwhere close to the chip.
quan said:My Shigaclone died last night-the pad at digital out lifted after too amny times fiddling and also C906 postision after trying to remove the large Auricap.
WRT extracting direct digital output from the chip-Peter can you help? How to go about it?
As you can see in a datasheet here: http://pdf1.alldatasheet.com/datasheet-pdf/view/40975/SANYO/LC78601E.html the DOUT on LC78601 is pin 29. Pick the ground somwhere close to the chip.
so, finally got started tonite and things are going well. I accidentally removed C930, so I need to figure out which value this is so I can replace it. Removing the 4 SMD caps was a bit tricky, and at this point they all measure as shorts when I measure across the remaining pads using the continuity check on my meter. I'm assuming this isn't too accurate. Is there a way to verify that these caps were removed successfully? I'm a bit worried about this, as there was a piece of one of the caps left under the heatsink and I removed it with a fine wire cutter... yeah... Also, for the clock it's hard to tell, but it looks that two of the pads are shorted together, but I cannot tell if I did this or not. Is this correct? Finally, what are people doing with the "Cap 6", whose function is unknown... removing, or keeping it?
Such precision work. I cannot image how Peter drilled though the PCB to gain access to that pin!!!!
Such precision work. I cannot image how Peter drilled though the PCB to gain access to that pin!!!!
luvdunhill said:
Get a strong magnifying glass and check all of those locations before you apply power to the board. With a reasonably good meter not set to the diode setting most ports will read a couple of hundred K, anything above a couple of K probably means you are ok.
Refer to the schematics for the RCEZ31 for the value of C930..
I am confused by the frequent complaints about how hard it is to remove smd parts. I do it all the time with a conventional iron, replacing them takes somewhat more skill I will admit. I usually apply enough solder to simultaneously heat both ends of the smd cap or resistor I am trying remove and apply the tip along the top or side of the package, wait a few seconds and push in a direction (usually sideways) where there are no close parts. Follow up with solder wick.. Some skill is required so practice on a junk board first..
Mine is sounding great. I think I am very close to finishing the electrical mods at this point.
also, a few more questions.
What does the green square in the second picture refer to? (lower right corner)?
Looks like C930 = 100uF? So, I have a short and a tall 100uF capacitor, both with the same working voltage. This is the cap left of E2 in the first picture. Can anyone confirm?
Also, remeasuring using resistance, I am still getting shorts across the removed SMD capacitors. Nothing obviously wrong looking via a magnifying glass... looks nice and clean. Can anyone verify/explain this? I have not put the new/upgraded components in, so all the parts that are marked for removal / replacement are not installed as I measure.
Oh, also can someone comment on if two of the crystal pads are tied together or not?
What does the green square in the second picture refer to? (lower right corner)?
Looks like C930 = 100uF? So, I have a short and a tall 100uF capacitor, both with the same working voltage. This is the cap left of E2 in the first picture. Can anyone confirm?
Also, remeasuring using resistance, I am still getting shorts across the removed SMD capacitors. Nothing obviously wrong looking via a magnifying glass... looks nice and clean. Can anyone verify/explain this? I have not put the new/upgraded components in, so all the parts that are marked for removal / replacement are not installed as I measure.
Oh, also can someone comment on if two of the crystal pads are tied together or not?
luvdunhill said:
Two words: crappy meter...
I have several very expensive lab meters, and none of these measure open, and I surmise your meter can't tell the difference between a short and a high impedance in this mode. All bets are off if your meter turns on the substrate diodes in the chips. (No damage, just a misleading reading, probably just what you are seeing.) Visual inspection is fine, and if you see no shorts then you should be fine. Get a better meter..