First time posting on this site. I just wanted to let people know that I am having the exact same issue that willy65000 described in his post a number of weeks ago. I purchased a Topping D50s to function as a preamp/DAC for my Parasound Zonemaster 2350 Amp. The output voltage is insufficient. I'm playing FLAC music of CDs ripped on Musicbee. I have an older Rotel preamp that drives the amp without issue. The Parasound says 2 volts should be sufficient but the D50s seems to not be up to the task. I've considered various work arounds but I feel like the Topping should work as is. Since it isn't, I'm going to return it. I'm looking at the Emotiva PT-100 instead with an output of 4 volts. I realize it's internal DAC may not be as good as the Topping but I need something that can drive my amp sufficiently. Thanks for reading and all the helpful info on this site