For several years, now, I have been presenting at trade shows using Chord product and PCM content. I've been a Chord fanboy since before Dave was launched. Rob Watts always impressed me with his digital expertise. Back in the day, I felt that Dave and MScaler was the penultimate combo but I discovered that all Chord DACs could be moved toward that level of transparency using AudioWise RF noise isolation and PGGB upsampling. So my daily listen for PCM evolved to a Mojo2 (tricked out as per my Reference/M2 setup).
When the PGGB development group introduced DSD output to raves reviews, I began to seriously consider the format. Chord DACs are PCM-centric, likely for marketing reasons and Rob's own pronounced preference for PCM. When playing a DSD file, a PCM DAC converts DSD to multi-bit PCM in hardware and this compromises the DSD signal. A proper DSD DAC maintains a dedicated DSD signal path for optimum DSD sound quality.
So in 2024 I purchased a Holo Cyan2 pure NOS R2R DAC with the requisite separate DSD signal path. I talk about that in this blog post. The Cyan2 is not the highest end Holo product but a good first step. As you move up the line to Spring and May, the improvements (for SQ) are mostly related to better component quality for improved noise measurements. Holo2 has a fantastic USB interface - galvanically isolated and filtered but apparently not with the new Titanis circuit. I had some compatibility problems with my OPTO-USB so my USB chain is my USB-CABLE and USB-FILTER. AC power is from my standard LiFeP04 battery to a low noise inverter to a RF-STOP filter using commodity cabling. I added a couple helpings of DAC-WRAP although I believe that Holo's R2R design, having far less dependency on digital logic of a PCM DAC like Chord, is far less susceptible to external EMF.
With my setup, the Cyan2 was amazing and quite clearly better at playing DSD than PCM. After more testing, it was obvious to my ears that DSD512 at 48kHz (DSD512₄₈) was the sweet spot: DSD256 had less resolution and DSD1024 had notably more distortion. When comparing PCM vs DSD on a Cyan2, the PCM was not even close. Despite all my experiments with RF isolation or PGGB settings, I could not make PCM achieve the stunningly crisp transparency of DSD. I tried 16fS or 32fS at 32-bits/24-bits or the recommended 20-bits (for maximum linearity) but DSD still provided more bass resolution, a more holographic presentation, better female vocals and a much less fatiguing listening experience.
Over the course of the past summer I spent my evenings comparing Cyan2/DSD and Mojo2/PCM. I fed both into my Benchmark HPA4 to HE1000se headphones and switched sources playing the same track: as close to a true A/B as i could get. Let me just summarize 4 months of listening: DSD512₄₈ on Cyan2 has transient attack, energy and realism unlike anything I'd heard before. Certainly, Mojo2/PCM is smoother sounding and familiar to me but it's maybe a step down from DSD in overall listening enjoyment. This is with maximum PGGB quality settings and maximum RF isolation on the DACs. So while I still listen to Mojo2 I am now loving DSD on Cyan2 and have PGGB converted over 200 albums to DSD and even my long duration classical reference tracks (thanks to PGGB-IT!'s Azure Compute feature).
I know I will get pushback on comparing Mojo2 rather than the higher end Chord DACs but I've heard them all and for a $500 street price, the Mojo2 is unbeatable. Similarly, the higher end Holo Audio DACs are objectively and subjectively better than Cyan2 (according to specifications and reviews) yet for a $1000 street price, the Cyan2 is a bargain for experimenting with PGGB processed DSD. Try it and you too will be amazed!