Passive attenuator impedance question

If this is happening Zd542 the dacs volume control is "bit stripping" in the digital domain, this will not happen with a passive volume control in the analog domain.

Cheers George

"07-06-15: Georgelofi

If this is happening Zd542 the dacs volume control is "bit stripping" in the digital domain, this will not happen with a passive volume control in the analog domain."

I know.

"I know that when you lower the volume on your dac, you loose some resolution. I've done quite a bit of testing, along with a few other audiophiles that were curious, as well. Using a very detailed system, we couldn't hear any difference whatsoever between low and high settings. I think you're far more likely to lower SQ than raise it."

Regarding "bit stripping," I would not extrapolate experience with Wadia models to models from other manufacturers, and perhaps even between different Wadia models.

The manual for the Wadia 121 states as follows:

Does the Wadia Volume Control compromise resolution?

The Wadia 121 Decoding Computer uses the latest generation of Wadia’s proprietary digital volume control. The volume level can be varied in the digital domain by means of mathematical manipulation of the signal, eliminating the distortion and noise that are inevitable with even the best analog volume controls. While conventional thinking indicates that reducing the volume digitally can sacrifice low level resolution, Wadia has created an innovative solution. Wadia’s patented digital filtering algorithm produces a 32-bit output. This high-resolution signal is then used in the computations that in turn reduce the volume level. This new signal is fed directly to the DAC chips. Through this innovative method, the Wadia 121 Decoding Computer maintains high resolution even at the lowest volume control settings.

While the manual for the 321 has no such statement but says:

A Volume Setting of 88% on the Wadia 321 will provide optimum performance when it is connected to a Preamplifier (Integrated Amplifier or Receiver).

Best regards,
-- Al

Mr G- Something that may be of interest to you: (http://www.partsconnexion.com/controls_attenuator_khozmo_series.html)

The 121 and 321, I believe are from Wadia's current offerings. I've never used either one, so I really can't comment on how they sound. But I have had many Wadia products over the years, and still have an 861SE and a 302. The owners manuals say to keep the volume above 67 for best sound quality. They also have dip switches (861's are internal, and the 302's are external) that allow you to alter the overall gain so that you can keep the volume setting as high as possible.

Just to make sure we are talking about the same thing, when I did the test, the idea was to see if we could hear a reduction in SQ at volume settings below the recommended 67. Throughout the day of testing, no one, including myself, could hear any difference whatsoever, regardless of low low we set the volume.

Taking the above into consideration, my advice to the OP is to see if you have a problem that needs to be fixed before you start. If you hear a noticeable difference at lower volumes, then it may make sense to try a passive volume control. But if you can't hear a difference, putting the volume control in the signal path, can't do anything positive.