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Old 21st June 2006, 07:01 PM   #391
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Perhaps the Hedge funds ought to start buying TDA1541's.
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Old 21st June 2006, 08:27 PM   #392
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Quote:
Originally posted by poobah
Judging by number of people trying to buy a pile of 1541's... there is every reason to debate the very purpose of this thread. The most revealing tests have not been performed. Linear interpolation creates spectra not found in the original signal... this may be pleasing to the ear... but it is NOT reproduction.
The question is, if it is an issue.
K2 of 10 kHz is 20 kHz, K3 is 30 kHz, who cares about that ?
K7 of 1kHz would be something to worry about...

Anyway...

...we don't want no no-sayers here in town
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Old 21st June 2006, 08:34 PM   #393
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Consider the fundamental premise behind this whole thing. Moving the frequency of the filter up.

Linear interpolation is creating spectra between 22 kHz and 80 khz... so what is the point? My simulations show that spectra are created BELOW 22 kHz. My sims are too crude to publish... but might the 100's of texts suggesting the same thing be credible?

I am not discounting EC's claim that it sounds better... only why?

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Old 21st June 2006, 08:43 PM   #394
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Quote:
Originally posted by poobah
My simulations show that spectra are created BELOW 22 kHz. My sims are too crude to publish...
See wanna
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Old 21st June 2006, 08:49 PM   #395
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What? Clarify?

I was working on a spreadsheet... but didn't save it.

I can redo it if anyone is terribly interested.

I actually believe the 8 DACs sound better because linearity errors are reduced by 8^0.5.
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Old 21st June 2006, 09:25 PM   #396
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Can you post a graph ?
At what frequency do harmonics start to pop up, let's say > -80 dB ?
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Old 21st June 2006, 09:27 PM   #397
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Quote:
Originally posted by poobah

I actually believe the 8 DACs sound better because linearity errors are reduced by 8^0.5.
Yes, perhaps, but one bad chip might spoil the whole thing,
and the best chip alone might be better than all together.

IMHO any sort of paralleling does only make sense if performance of all chips is equal.
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Old 21st June 2006, 09:45 PM   #398
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Quote:
Originally posted by Bernhard



...we don't want no no-sayers here in town
And no clueless photographers either.
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Old 21st June 2006, 09:56 PM   #399
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I really must take issue with the idea that there is any reduction in non linearity due to the number of dacs used.
Though the outputs are summed, they are summed simultaneously, not in parallel and as such each dac sees the I/V stage in isolation. The second reason is that the method chosen to create a balanced output sums alterrnate samples so there is no reduction due to the common mode effect.
In short the DACs are not in parallel and there is no common mode rejection when in DI mode.
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Old 21st June 2006, 10:27 PM   #400
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I agree rfbrw... I am only posing this as a possible explanation for the subjective reports.

Bernhard, I could recreate the spreadsheet and email it to those interested... the graph would not post here well.

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