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-   -   Real or fake? (http://www.diyaudio.com/forums/digital-line-level/207013-real-fake.html)

SoNic_real_one 18th February 2012 03:28 PM

Real or fake?
 
2 Attachment(s)
I have bought two PCM61P-K. I have a small doubt - I was thinking that they would have "Japan" written on them. My "regular" PCM61P have "Korea".
Are the -K looking "real"?

SoNic_real_one 18th February 2012 04:50 PM

1 Attachment(s)
Update - I just received another batch. Those are marked "Japan". Probably because are older, before TI aquired BB (september 2000)?
Does that mean that the 2001 from above are made in USA? I did put them in, they sound good. Very good...

Nikola Krivorov 18th February 2012 05:22 PM

Hi,
I had a similar doubt about a pair of PCM63 chips with a Y grade and most of the people said that it did not make sense to have the chips made to meet a certain grade, the grading is made after testing and should not be laser etched :(

SoNic_real_one 18th February 2012 06:13 PM

They can be etched after the selection. I would think that, in that case, the packaging has to be done in the same plant as the foundry.
They work, so they are real chips. The "normal ones" that I had are painted, not etched - it would take serious effort to erase that paint and etch the new label.
I think they are "real"... but I wanted to hear other oppinions.

Nikola Krivorov 18th February 2012 07:18 PM

Well,

I was just saying what my research lead me to, you can probably have a look at this thread
http://www.diyaudio.com/forums/digit...ake-pcm63.html
(better not, will take quite some time to read through). It is of course about the PCM63, might be different with the 61 but the idea was that they laser etch the logo and then when they grade it they use some kind of whitish ink to mark the grade. It will be sort of difficult to put them back for laser etching the grade again. The only important thing is how they sound though, I don't really care about the grade and I prefer to listen to them. From a batch of probably 60 K grades we could definitely hear differences in sound. My friend beauty_devine who started the thread has worked for Alcatel in actually making chips and he knows a thing or two about it, grading doesn't always mean better sound so I suggest you just enjoy them if they sound good. Sorry if that is not what you wanted to read but this is what I know about the grading.

Tam Lin 18th February 2012 07:21 PM

Quote:

Originally Posted by SoNic_real_one (Post 2912330)
They can be etched after the selection. I would think that, in that case, the packaging has to be done in the same plant as the foundry.

True, but that's not the way they did it in the old days. The grade was stamped on after the chips were assembled, labeled, and tested.

PCM61PK Photo

The chips may work but are they PCM61P-K. The 16-bit PCM56 has the same pinout.

SoNic_real_one 18th February 2012 08:17 PM

Oh, well... They where from two "different" sources.
I might try to piggy-back all of them.

5th element 18th February 2012 08:32 PM

Well you could try measuring the output of the DAC with a computer sound card. -92dB specification isn't all that 'impressive' most decent modern sound cards should be able to better that. As you've got several you could compare the measurements, they should theoretically all measure the same, the impulse responses should be the same, as should the frequency responses and the overall non-linear distortion plots.

SoNic_real_one 18th February 2012 09:00 PM

I need a 991Hz test CD :) A FFT software that can output that.
RMAA, TrueRTA?
I have a Creative X-Fi Platinum card.

5th element 18th February 2012 09:08 PM

Ah I see, so no digital input, that could make things a little more complicated in that you wont be able to do a number of tests, but you will still be able to look at a 1kHz test tone, that should be fairly decent. If the input to the sound card goes up to 192kHz you could also check the noise profile above 20k on the output of the DAC.


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