Hearing "static" type noise with Vivaldi directly powering amps

I decided several weeks ago to replace my Momentum pre-amp with a new Momentum HD model. While waiting for my new amp to be built I decided to connect my Vivaldi DAC directly to my M-400’s and see how it sounded without a pre-amp. I had previously performed comparisons with earlier iterations of my system and the benefits of a pre-amp always outweighed the benefits of going direct. Well the Vivaldi DAC direct is the first piece that has me wondering whether a pre-amp is just providing flexibility and no longer SQ benefits.

The small issue I have going direct is that I hear a short burst of “static” type noise as the DAC is changing tracks. This is most apparent within playlists where sampling rates change. With my Momentum pre-amp in the loop I never heard this noise even playing the same playlists. If I remember correctly we previosly added a “Resync Delay” which we were able to remove with one of the updates. Would that correct my problem until my new preamp arrives?

The Momentum amps are DC coupled which means that there is no filtering on the amp’s input. When the Vivaldi switches rates the mute relays engage and as these are mechanical devices there are often some spurious transients that make their way through and the amp happily amplifies those.

With a preamp in place you weren’t hearing them as the preamp’s volume control was attenuating them. In your configuration they’re outside the scope of the DAC’s volume control so the amp applies full gain. As long as they aren’t LOUD then there’s nothing to be concerned about.

There can also occasionally be some clicks and pops emitted from the DAC circuit during certain rate / format changes. It’s worth turning the DAC’s buffer on (if it isn’t already) to see if that makes a difference.

Andrew, Thanks for the explanation. I do have the DAC Buffer set to on but as you guessed it does not help.