Hi All,
Reading through various threads, there seems to be 2 camps over whether the Double Crown chips sound better or not.
As the Double Crowns were selected items, it seems reasonable to assume that there are many chips out there with the same performance.
Is there any way that a tester could be put together to test chips to the double crown standard (other than using your ears)
Andy
Reading through various threads, there seems to be 2 camps over whether the Double Crown chips sound better or not.
As the Double Crowns were selected items, it seems reasonable to assume that there are many chips out there with the same performance.
Is there any way that a tester could be put together to test chips to the double crown standard (other than using your ears)
Andy
I was under the impression that as part of the manufacturing process all chips were tested and graded.
It follows that (unless the chips change) it would only be possible to further grade chips from a particular grade. For example it could be possible to find 2 standard chips of which one is very close to the higher grade and one very close to the lower grade.
Surely it must be obvious, even to those lacking my level of cynicism, that most of these crown chips suddenly appearing are fakes.
sp
It follows that (unless the chips change) it would only be possible to further grade chips from a particular grade. For example it could be possible to find 2 standard chips of which one is very close to the higher grade and one very close to the lower grade.
Surely it must be obvious, even to those lacking my level of cynicism, that most of these crown chips suddenly appearing are fakes.
sp
poynton said:
Trouble is, afaik, Philips never published the S2 specification. The best we have is from the February 1991 datasheet:
TDA1541A/N2 (ie. the plain old TDA1541A):
bit 1 - 16 Edl < 1 LSB
TDA1541A/N2/R1 (ie. TDA1541A R1)
bit 1 - 16 Edl < 2 LSB
TDA1541A/N2/S1 (ie. TDA1541A S1)
bit 1 - 7 Edl < 0.5 LSB
bit 8 - 15 Edl < 1 LSB
bit 16 Edl < 0.75 LSB
(Edl = differential linearity error)
We can only assume that the S2 grade has a specification that betters the S1.
Perhaps a way to test the chips would be with an audio test CD that has various waveforms (ramp/sine/triangle extending over the whole digital range) and measure the monotonicity of each step on the analogue output?
Re: Re: TDA1541A - Double Crown - Myth or Fact - How to Test
Not true!!
Will post specs later!
musicomputer said:
Trouble is, afaik, Philips never published the S2 specification. ....
We can only assume that the S2 grade has a specification that betters the S1.
Perhaps a way to test the chips would be with an audio test CD that has various waveforms (ramp/sine/triangle extending over the whole digital range) and measure the monotonicity of each step on the analogue output?
Not true!!
Will post specs later!
Attachments
I created such a test CD for linearity testing, as described here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=113620
The issue is that it works in NOS mode (SAA7220B/P bypassed) only, otherwise the signal on the oscilloscope can not be properly evaluated visually.
I encourage you guys to download the zipped file from here and try it:
http://tube.fw.hu/lintest.zip
You need a low-noise 100x amplifier to make the low-level steps visible. Waiting for your feedback.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=113620
The issue is that it works in NOS mode (SAA7220B/P bypassed) only, otherwise the signal on the oscilloscope can not be properly evaluated visually.
I encourage you guys to download the zipped file from here and try it:
http://tube.fw.hu/lintest.zip
You need a low-noise 100x amplifier to make the low-level steps visible. Waiting for your feedback.
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