DSDAC MKII with volume attenuator (Passive Preamp) Click noise

I’m using a passive preamp attenuator to control the volume of the pair of Genelec active speakers (8331A).

I notice a presence of click noise (quite Big) when using a passive 48-step volume attenuator. The Passive Preamp I’m using is the Luminous Audio Technology’s Axiom II Passive Preamp Walker Mod XLR.
Any thoughts on settings to avoid the clicks? I’m suspecting, the DAC is letting out Direct Current to the outputs (both RCA and XLR)

PS: I recall Ted mentioning that the optimal volume level on the MKI being around 92-93. Has this setting changed with the MKII, or better fix the volume at 100 for optimal sound performance?

Surely the passive pre is after the dac (via XLR or RCA) so it must be that that is breaking an earth or something?

Can’t point to them directly, but @tedsmith has mentioned in a few posts that there are design differences b/t the MK I and MK II that make the volume setting sweet spot a non-issue for the MK II. Its more a matter of what works best to your ears with your gear.



There is absolutely no DC on the DirectStream DAC (Snr) MkI or MkII outputs. They are both transformer-coupled passive output stages.

Do you get the clicks when changing the Axiom’s volume while no signal is playing? I’m thinking that maybe the click is related to the mechanical switching of the two phases not occurring in perfect unison. If that’s right, you should get no clicks from a zero signal adjustment – but if DC were the problem it’d be present even without signal.

Oh, and make sure the DAC’s RCA outputs have nothing connected to them. Those terminals are wired directly to the positive XLR phase. Again: passive transformer-coupled output from the DAC.

As @scotte1 said, the MkII doesn’t have the constraint that’s present in the MkI with regards full volume setting. From the DAC’s perspective, 100 is best and turning it down has only one downside which is the reduction in SNR between the audio and the noise floor.

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Thanks. I’m sending the Axiom II back to Luminous Audio so that they can check the attenuator. I shall make a feedback when they replace the amp.