Re: PIEZO.
Hi
Oh yes, I am very aware (include cables, capacitors and whatever)
I mentionned these as the subject as CD players, only.
best regards
fdegrove said:
Hi
Oh yes, I am very aware (include cables, capacitors and whatever)
I mentionned these as the subject as CD players, only.
best regards
Hi Jocko, glad you're back !
Is complaining about a chip from 1985 not a bit misplaced ?!?! There was not much choice either at that time.
Is complaining about a chip from 1985 not a bit misplaced ?!?! There was not much choice either at that time.
No......
Because a lot of guys still use CDPs that have one inside. Look at all the guys doing this non-o/s stuff What kind of filter do you think they have (before they rip it out)?
And do you think that the SAA7310 in your CD-80 is any better, and doesn't have that problem? I suspect that it does.
The point is.......just sticking a better clock in a CDP is no guaranty that things will sound better. Every CDP I have worked on uses the filter chip for the clock, and it has an output buffer that feeds the rest of the unit.
When I get all my setup back up and working, I will make audio files of the differences, and post them. May take a while......be patient.
Jocko
Because a lot of guys still use CDPs that have one inside. Look at all the guys doing this non-o/s stuff What kind of filter do you think they have (before they rip it out)?
And do you think that the SAA7310 in your CD-80 is any better, and doesn't have that problem? I suspect that it does.
The point is.......just sticking a better clock in a CDP is no guaranty that things will sound better. Every CDP I have worked on uses the filter chip for the clock, and it has an output buffer that feeds the rest of the unit.
When I get all my setup back up and working, I will make audio files of the differences, and post them. May take a while......be patient.
Jocko
Re: No......
not mine! some of the newer Sony SACD players use what they call "direct digital synch" DAC clock, which feeds the clock signal directly to the DACs; the filter etc. get the signal in parallel. of course there's a yucky 74HC chip used to buffer and distribute the clock, but that can be remedied fairly easily. the crystal is actually placed right on the DAC/analog board by the DAC chips, with all the digital circuitry on a separate board.
Jocko Homo said:
not mine! some of the newer Sony SACD players use what they call "direct digital synch" DAC clock, which feeds the clock signal directly to the DACs; the filter etc. get the signal in parallel. of course there's a yucky 74HC chip used to buffer and distribute the clock, but that can be remedied fairly easily. the crystal is actually placed right on the DAC/analog board by the DAC chips, with all the digital circuitry on a separate board.
You missed the key phrase "that I worked on". No. I don't work on SACD, much to the chagrin of a certain Ren-like associate.
And what are you going to replace that "yucky 74HC" part with? Some of that 'AC crap? HC is plenty fast.....any faster and you will get ground bounce.....which means jitter........
Just ask Guido if you don't believe me, but you need to......
And what are you going to replace that "yucky 74HC" part with? Some of that 'AC crap? HC is plenty fast.....any faster and you will get ground bounce.....which means jitter........
Just ask Guido if you don't believe me, but you need to......
AC cmos
AC CMOS sounds dreadful in any digital audio equipment I ever built. It rings, puts more trash on the supplies, and makes more signal integrity demands on termination use. As my guru Howard says: "Never use faster logic than required."
http://www.sigcon.com
Interesting that after AC logic was introduced, a whole new class of CMOS with faster edge rates than HC CMOS but addressing the shortcomings of AC CMOS. Many logic designers don't like AC CMOS and we tried not to use it in many telecom designs where I
worked. EMI considerations were the biggest problem.
yucky 74HC ........... amateurs.
AC CMOS sounds dreadful in any digital audio equipment I ever built. It rings, puts more trash on the supplies, and makes more signal integrity demands on termination use. As my guru Howard says: "Never use faster logic than required."
http://www.sigcon.com
Interesting that after AC logic was introduced, a whole new class of CMOS with faster edge rates than HC CMOS but addressing the shortcomings of AC CMOS. Many logic designers don't like AC CMOS and we tried not to use it in many telecom designs where I
worked. EMI considerations were the biggest problem.
yucky 74HC ........... amateurs.
hi fred. long time no talk.
jocko, wasn't trying to prove you incorrect. was just pointing out that my very mass-market Sony changer had a nice design touch in it.
as for the HC vs. AC, i'm sure you guys are right, but i was thinking more along the lines of removing the logic entirely and driving everything with Elso's clock circuit, based on an AD comparator. i'm not sure if the fanout will be too much but Elso seemed to think it would work just fine.
here's an old thread on the clock in my player btw, has the clock circuit diagram in it:
http://www.diyaudio.com/forums/showthread.php?threadid=8462
it's actually a HCU, i forget what's the difference between that and a HC...
jocko, wasn't trying to prove you incorrect. was just pointing out that my very mass-market Sony changer had a nice design touch in it.
as for the HC vs. AC, i'm sure you guys are right, but i was thinking more along the lines of removing the logic entirely and driving everything with Elso's clock circuit, based on an AD comparator. i'm not sure if the fanout will be too much but Elso seemed to think it would work just fine.
here's an old thread on the clock in my player btw, has the clock circuit diagram in it:
http://www.diyaudio.com/forums/showthread.php?threadid=8462
it's actually a HCU, i forget what's the difference between that and a HC...
HCU
HCU is unbuffered and contains only one inverter per gate. This makes it useful in amplifier and oscillator applications.
HCU is unbuffered and contains only one inverter per gate. This makes it useful in amplifier and oscillator applications.
oh yeah
this is off topic, but while i've got jocko's and fred's attention...
have you guys heard of this ERS material? i mention it in another thread... carbon fibre fabric impregnated with strands of metal alloys... supposedly derived from military stealth/diplomatic quiet-room applications. have you encountered this in the telecom industry?
this is off topic, but while i've got jocko's and fred's attention...
have you guys heard of this ERS material? i mention it in another thread... carbon fibre fabric impregnated with strands of metal alloys... supposedly derived from military stealth/diplomatic quiet-room applications. have you encountered this in the telecom industry?
Well, as far as i know the SACDs of Sony use a 45MHz clock.
45MHz is a bit much for standard HC logic, isn´t it?
I have replaced it in my Sony DAC to a VHC inverter and sound
became definately better - no doubt! It is fed with 49.125 MHz
45MHz is a bit much for standard HC logic, isn´t it?
I have replaced it in my Sony DAC to a VHC inverter and sound
became definately better - no doubt! It is fed with 49.125 MHz
Like I said........
"Interesting that after AC logic was introduced, a whole new class of CMOS with faster edge rates than HC CMOS but addressing the shortcomings of AC CMOS"
And VHC is one of those families. I notice you didn't use AC CMOS.
"Interesting that after AC logic was introduced, a whole new class of CMOS with faster edge rates than HC CMOS but addressing the shortcomings of AC CMOS"
And VHC is one of those families. I notice you didn't use AC CMOS.
I think rbroer has a point afterall:
Typical PLL stops working on a quite high freq due to that the receiver chip needs to have a sufficient capture range.
Mechanical feedback when playing loud would most certenly come into play. By freeing the osc from the chassis, the frequency which would influence the osc will rise considerally and maybe end up within the PLL (>1 khz?) range and thus filter out the contribution from mechanical feedback.
/
Typical PLL stops working on a quite high freq due to that the receiver chip needs to have a sufficient capture range.
Mechanical feedback when playing loud would most certenly come into play. By freeing the osc from the chassis, the frequency which would influence the osc will rise considerally and maybe end up within the PLL (>1 khz?) range and thus filter out the contribution from mechanical feedback.
/
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