Re: Re: Re: Re: Separate DACs for each halfwave ?
Thank you lgrau, but I have been aware of BB's colinear process and the problem it is meant to solve for a few years now.
If you look at the binary 2's complementary digital code that corresponds to +/- FSV, you will see that all the codes increment or decrement in steps of 1 lsb except for the code between highest negative value and bipolar zero where it goes from all 1's to all 0's. This sudden discontinuity contributes to the non-linearity of the device, especially at lower levels where the signal is continuously transitioning around bipolar zero and any non-linearity is a larger component of the signal compared to the higher levels.
Interesting, but to a large extent it solves a problem that has already been solved.
Lgrau said:
Lgrau said:
Thank you lgrau, but I have been aware of BB's colinear process and the problem it is meant to solve for a few years now.
bricolo said:
If you look at the binary 2's complementary digital code that corresponds to +/- FSV, you will see that all the codes increment or decrement in steps of 1 lsb except for the code between highest negative value and bipolar zero where it goes from all 1's to all 0's. This sudden discontinuity contributes to the non-linearity of the device, especially at lower levels where the signal is continuously transitioning around bipolar zero and any non-linearity is a larger component of the signal compared to the higher levels.
Bernhard said:
Interesting, but to a large extent it solves a problem that has already been solved.
Re: Re: Re: Re: Re: Separate DACs for each halfwave ?
Not really.
A few people still use some old TDA1541 chips which could make good fortune from that 😉
rfbrw said:
Not really.
A few people still use some old TDA1541 chips which could make good fortune from that 😉
For the ones that don't know colinear and other techniques mentioned this is a nice read:
http://www.web-ee.com/primers/files/DesignSem5.pdf
http://www.web-ee.com/primers/files/DesignSem5.pdf
Re: Sorry, off topic again....
* Beside the fact that the ear is subjective, it is a very good instrument.
But ability to find out where lies the errors is limited.
That's what an analyzer is good for.
* Thanks, if you have a pair of PCM56K ( these are inside the DCD3300 ) that would be nice, I would try parallel them.
18bit chips seem not to be compatible, I tried PCM61 and it only distorts.
* Still waiting for the damn comparator for Kwak clock.
* What you think about PCM1702 & AD1862 ???
jean-paul said:
* Beside the fact that the ear is subjective, it is a very good instrument.
But ability to find out where lies the errors is limited.
That's what an analyzer is good for.
* Thanks, if you have a pair of PCM56K ( these are inside the DCD3300 ) that would be nice, I would try parallel them.
18bit chips seem not to be compatible, I tried PCM61 and it only distorts.
* Still waiting for the damn comparator for Kwak clock.
* What you think about PCM1702 & AD1862 ???
any hint how to obtain a pair of AD1862?
Is it me beeing stupid or is another number meant? I can´t find AD1860. Jean-Paul, did you mean 1861?
What would be quality differences between 1861 and 1865 ?
To what did you connect the PCM61, to a reciver? which? did you set the right output mode? Does it give distorted sound, or digital noise?
Paralleling selected chips with standard ones brings nothing.
Are you sure PCM61 survived the desoldering ? PCM63 almost never survives desoldering, even when antistatic measures are taken and heat is applied carefully so maybe this one is as sensitive. And/or are you sure you set things in the right mode ?
In case that you don't have the datasheet:
http://neutrino.phys.washington.edu/~berns/archive/misc/PCM61.pdf
AD1860 is pin compatible with PCM56, you can enable 18 bit in the digital filter in most cases. Again, I don't know DCD3300 so I am not aware of the schematics. Till, AD1860 was a direct replacement for PCM56 in its days. Not much on the web on AD1860 but after all these chips were from before internet existed 😉 They also did not exist that long. There were more nice chips like PD0050 ( 20 bit dig. filter, Pioneer ) and PD0037 ( dig. receiver, Pioneer ), I was never able to find any info ( datasheets ) on them except for some schematics I have ( and the chips NIB ).
I know PCM1702 from Denon cdplayers ( probably the dreadful DCD2700 !?! ) and the Denon 500 separate DAC which I owned once. I wasn't too impressed after various mods. PCM63-K is better for me. If it wasn't for TDA chips I would still be busy with PCM63-K I think. I skipped PCM1704 because its SMD, not my favorite way of working.
AD1862 is one of the few multibit DAC chips that I never have heard ( at least not that I am aware of ).
For the adventurous types, I have UDA1350AH, UDA1351TS, PCM1728, PCM1738, YM3623 ( old ), SM5813 (old ), and PCM58-J (old) for trade with other nice audioparts....
Are you sure PCM61 survived the desoldering ? PCM63 almost never survives desoldering, even when antistatic measures are taken and heat is applied carefully so maybe this one is as sensitive. And/or are you sure you set things in the right mode ?
In case that you don't have the datasheet:
http://neutrino.phys.washington.edu/~berns/archive/misc/PCM61.pdf
AD1860 is pin compatible with PCM56, you can enable 18 bit in the digital filter in most cases. Again, I don't know DCD3300 so I am not aware of the schematics. Till, AD1860 was a direct replacement for PCM56 in its days. Not much on the web on AD1860 but after all these chips were from before internet existed 😉 They also did not exist that long. There were more nice chips like PD0050 ( 20 bit dig. filter, Pioneer ) and PD0037 ( dig. receiver, Pioneer ), I was never able to find any info ( datasheets ) on them except for some schematics I have ( and the chips NIB ).
I know PCM1702 from Denon cdplayers ( probably the dreadful DCD2700 !?! ) and the Denon 500 separate DAC which I owned once. I wasn't too impressed after various mods. PCM63-K is better for me. If it wasn't for TDA chips I would still be busy with PCM63-K I think. I skipped PCM1704 because its SMD, not my favorite way of working.
AD1862 is one of the few multibit DAC chips that I never have heard ( at least not that I am aware of ).
For the adventurous types, I have UDA1350AH, UDA1351TS, PCM1728, PCM1738, YM3623 ( old ), SM5813 (old ), and PCM58-J (old) for trade with other nice audioparts....
thanks, that makes clear why i´m also without success
were to find it?
seems like also not to find.
PCM63 is not hard to find, although it's been declared obsolete. Prices were OK too when I bought them last year. When I bought them several years ago they costed me 160 dutch guilders a piece ( about 75 euro ) !!!
Bought them a few times at Schuro.de but they've disappeared from their website.
Bought them a few times at Schuro.de but they've disappeared from their website.
till said:
* Not yet.
* I plugged the PCM61 into the socket of the PCM56 in the CDP.
Sound was distorted strongly.
Data sheet say that these are pin compatible.
jean-paul said:
* The two PCM56s in my Denon are "K", the ones you have are ???
* They are NOS.
* are you using desoldering pump ?
* The DCD3300 has big smd SM5804D and Sony CXD1125 + Ram on an extra board. What is the Sony chip ?
* Not AD1856 ? Data sheet of PCM56 say so.
Re: Re: Re: Re: Re: Re: Separate DACs for each halfwave ?
Yes really. That you choose not to use the available solution does not in any way negate it. If you want to live in the past, you're on your own.
Bernhard said:
Yes really. That you choose not to use the available solution does not in any way negate it. If you want to live in the past, you're on your own.
Bernhard said:
*PCM56-K are highest grade, no need for upgrading these. Only 18 bit pincompatibles are an option. This inludes setting the NPC chip in the right mode.
* I used antistatic desolderpump then but my experience with PCM63 is that it fails often when soldered out. They also sometimes just fail when in use, very frustrating ( this was with early versions ). Anyway, using new ones is what I did after that. If you want to experiment with those, better use a high Q socket.
*SM5804 is ( 4 x ?, can't find the datasheet in my collection ) digital filter, Sony CXD1125 is DSP.
* Not only AD1856, also AD1860 was an attempt of AD to produce a pincompatible chip but with higher 18 bit resolution. I have a selfmade DAC I made in that time in my hands now and its clearly written on them : AD1860.
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