Does Pass D1 roll off treble at low volumes? - diyAudio
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Old 17th September 2006, 10:30 AM   #1
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Default Does Pass D1 roll off treble at low volumes?

Hello all,
In the following review of the Pass D1, it mentions that at low volumes the treble is rolled off, I'd like to know if that is true?
Ultimate Audio Review of Pass D1

I simulated the I/V stage, where the volume is, and I cannot see where the high frequency roll off occurs. The opposite in fact, as volume is lowered (by lowering the resistance of R5 in my schematic, the frequency response is extended, because C1 and C2 have less of an effect. This is what I expected from looking at the schematic.

What I'd like to know is:
1. Is the review correct or incorrect
2. If correct, where in the circuit does the rolloff occur?

Cheers, Adrian
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Old 17th September 2006, 10:53 AM   #2
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I think reviewer described what he actually heard, not what measured, and this may have nothing to do with measured performance of the circuit.

According to service manual D1 has 24 step series type attenuator at the output. At low volume levels there are as many as 15 up to 23 resistors and solder connections in the signal path, and I suppose this might effect the sound to some degree.

Bartek
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