Please check the maximjm input voltage of your pre-amplifier and set the Weiss output voltage (analog domain) equal to that voltage and also set the digital volume on Zero db.
David
@ddk believes the only dac with good bass (like top turntables) is Weiss .
Have fun and enjoy
I know and sale WEISS for 4 years now. It's of of the best DAC that has quite perfect bass to my experience.
Bass is premium, fast, clean. Certainly one of the very best I know, the other is PLAYBACK DESIGNS which is a bit different. The other is from a UK well known digital company. I would rank WEISS in 2. PLAYBACK is quite as fast, as clear but with a lot of aplomb. I prefer PLAYBACK because it's more dynamic and more "real". If the difference is quite small, the Californian company is closer to unamplified music. Also PB MPD-8 (dream line) is more expensive than HELIOS and has no streamer like the Swiss DAC. So HELIOS competitor is more PB DESIGNS MPD-6. In any case, I do not use volume on DAC event if PB DESIGNS has a real preamp analog output. I use only volume control on my APURNA™ Soprano Limited Apogée monoblocs that have each their true monoral preamplifier.
I will test HELIOS vs my MPS-8 that has a STREAM-X2 inside, it's a comparison at quite the same price (MPS-8 is more expensive because it also has a CD/SACD transport), and I do it now because my MPS-8 is on sale
www.phpaudio.fr