finneybear said:
The question is that I have build me DAC's with a very low jitter clock with which I reclock the clock-signals as well as the digital audio signals just before they enter the PCM. I explaned this many postings before.
Other and for all, if the input signals of the PCM are realy jitter free (< 0.5 ps) then the differences between the K's Y's and.... are minor.
Your other remarkes: My first op amp design was in 1966.
spencer said:
flshzug said:
In the above mentioned eight years old article of Hawksford you could find in the last sentence of paragraph 3-4 Observations:
However, if the signal is filtered to remove the sample structure this should reduce the level of modulation, where this appears to be born out by the process of pre-filtering of the DAC output current prior to I/V conversion.
and one of his recomandations is:
• Pre-filter the DAC output current with a passive low-pass filter.
This is precicely what I do by simply connect a 10 nF capacitor across the output pins of the PCM.
Because of the noise performance 5 nF could be better, but listen first!
PA0SU said:
Spencer, Paul, Fynni and all others:
Seemed to me that this becomes the true TOPIC here.
Moreover:
PA0SU said:
Well, seemed that Herb might have got it on the right track. Any suggestions how to follow up on this??
PA0SU said:
So? Jitter is only part of the game. Every PCM63 chip is not the same. They will perform differently even when you feed them the same 100% time accurate PCM stream. That's it. Simple. You will not want me to get into details about what's inside a PCM63, will you?
This statement, combined with your messages above such as so called audio applications, only show me that you must have not touched OP designs for a long time. 😀
-finney
irgendjemand said:
I also do'nt know the real history of the different IC's. Of course not. But to say that some of them are fake, this means that corruptive people behaved as criminals selling them with another stamp on it, is mutch to heavy to me. The more the IC's show the same performance differences.
I gues your IC's are ordinary P's later selected as Y for one reason or another....
PA0SU said:
J, K, K2, KY, and Y are all picked through part sorting process. They are all originally Ps. 😀
If the volume is not high, it will not make sense to do laser marking simply for the Y grade. In other words, before we find the reason that TI/BB would do laser mark on Y chip, it will be a better idea not to spend money on those laser marked Y chips.
PA0SU said:
Nothing new here. Look at the NP D1 DAC done by Spencer. The by-pass cap is there, too. Nelson Pass did that long ago already, that is.
It all comes down to how good it is and the answer is, the bypass cap is only a partial remedy. I/V stage itself is still a monster full of problems, especially when you choose the wrong OPs.
PA0SU said:
I get sick of you Finney
Many people are sick of me, and I am proud of it. As far as more people love me! 😀
finneybear said:
Finney,
This sounds absolute right to me. Just as a remark here - I am using a matched pair of this Laser marked "Y" (see picture), which sounds MUCH better then the "J" which I originaly got with the DAC and the 3 pairs of genuine "K" (Korea, Phil and USA) which I got later on.
Yet I am looking for a pair of genuine "Y". Not easy to find!
IJ.
Attachments
Finney,
Finney, in all honesty, I just don't get what the hell are you talking about?
Do you REALLY think that at BB they selected the grades BY EAR?
Or, is it the same Finney who says also this:
Now, IF they were selected from the same batch by measurements, and these measurements are there, described in the data sheet, AND many people here repeated them [except for You] and got totally different results - like, the normal P's measuring better than the K's- then what is that difference, that You are hearing in your super dac system? The effect of that letter stamped on the chip for some reason? Because the REAL grade differences should be measurable... could you show us here your results, confirming this, please?
And then, for objectivity, someone else maybe could have a look at the same chips?
Sincerely Yours, George
Finney, in all honesty, I just don't get what the hell are you talking about?
Do you REALLY think that at BB they selected the grades BY EAR?
Or, is it the same Finney who says also this:
Now, IF they were selected from the same batch by measurements, and these measurements are there, described in the data sheet, AND many people here repeated them [except for You] and got totally different results - like, the normal P's measuring better than the K's- then what is that difference, that You are hearing in your super dac system? The effect of that letter stamped on the chip for some reason? Because the REAL grade differences should be measurable... could you show us here your results, confirming this, please?
And then, for objectivity, someone else maybe could have a look at the same chips?
Sincerely Yours, George
Joseph K said:
George,
I am sure Finny will answer you, but how about you sending me your "Y" chips for objectivity? If I do remember it right, your "Y" are not in use at this stage.
The meeting I scheduled for this (and other) subjects is in about 1 month from now, in Bavaria. I will be meeting with my technician, Manfred Hiller; we are going to LISTEN to the differences in several implementations of "P", "J", "K" and "Y". There will be 2 CD Players and 2 DACs, all of which are working with PCM63...
Greetings!
The problem could be aging.
Also BB measured THD + N as a bare number.
They looked only on quantity not on quality.
Also BB measured THD + N as a bare number.
They looked only on quantity not on quality.
Joseph K said:
George,
What you are saying is that SONY, YAMAHA (etc.) were putting in their absolute leading gears - the worth measured BB PCMs crap... This doesn't sounds too plausible, isn't it?
AND: Most members here also agree that there are several ways to measure. Several of them went through difficulties, without getting clear results. Bernhard was saying already before that we have to face the fact of AGING as well, etc. If so, we might be way too late for this measurements nowadays!!
We even don't know for sure the correlations between measurements and sound, just partly.... In such conditions, who care the hell about the measurements? 😉
I trust BB, SONY and YAMAHA engineers.
Moreover: Our ears are much more sensitive then one thinks. You might well hear also exactly that what you wrote above as a provocation – the effect of the letter stamped on the chip as well for some reason (be careful, you might well hear in a BLIND TEST!).
Keep measuring, why not? seemed to be a lot of fun. Or better - simply go after your ears: It is SO EASY to hear the differences between P, J, K and Y. It is almost embarrassingly easy!
I remember however your arguments that you are using the good electronics. Still, try comparing the sound of your system to the sound coming from natural sounding classical-music studio-monitors. They vibrate in a natural way.
You will here there EVERY difference, EVERY element, EVERY PCM, EVERY condensator, relais, selection-level, OpAmp, Clock.... 😉
Greetings!
Bernhard said:Best not forget the Korkscheibchen
Bernhard, as no other mambers here knows about the "Korkscheibchen", let me just tell you that they are not inside my Marantz CD-10 or DAC. However, don't underestimate them in the old Marantz CD-40.
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