Many audiophiles have multiple sound systems, each in its own listening space. The primary system is for critical listening, typically loudspeaker-based in a dedicated room, while the secondary system is for more casual listening, perhaps bookshelf speakers in an office or common room. Sometimes the primary system is an elaborate analog rig, while the secondary system is a simpler digital setup. Conversely, the primary system might be high-end digital, and the secondary system, tabletop digital. Ultimately, the choice is determined by budget, available space, and individual listening preferences.
Headphone systems are increasingly common in smaller living spaces. In small homes or condos, audio systems need to scale down: bookshelf speakers replace floor-standing speakers, an integrated tabletop replaces a rack of components, and headphones replace speakers altogether. This was my own personal situation – downsizing my audio system while still maintaining the high quality I was accustomed to. And it had to be compatible with my collection of PGGB upsampled PCM@16fS and DSD512 content.
So it was on a whim that i purchased, in early January, second hand at a good price, the highly regarded Astell & Kern SP3000M. Yes, a DAP. I chose it due to the quad AKM DAC design with its dedicated DSD signal path and low distortion. I expected to enjoy this unit while I was shopping for my downsized system. What i did not expect was that it played DSD512 with such fidelity and transparency that, IMO, it bested my Laptop->Cyan2->HPA4 reference rig. Whaaat?
Could it be that A&K is onto something with the SP3000M design? Their product literature describes a technical tour-de-force: source, memory control, DAC, power, analog section (including op-amps) plus extreme RF/EMI shielding in a compact design. It drove my HE1000se through the 4.4mm balanced output to great effect ...no shortage of power. I was just wowed - but I needed a full A/B test.
1) SP3000M -vs- Cyan2/HPA4. A slight edge to the SP3000M for sound quality. Note that the Cyan/HPA4 setup was 5x the cost of the SP3000M and involved a source (laptop), filtered USB and my reference battery/inverted power. The SP3000M, being compromised by battery power, could only last for 3-4 hours playing DSD512. (I did run the SP3000M with permanent USB-C charging and noted no difference in SQ - a feat in itself).
2) SP3000M -vs SP3000M/HPA4. The HPA4 connection used Line-out from the SP3000M (6.3 Vrms). I expected the better amplification of the HPA4 would win the contest, but no. The SP3000M sounded so much more transparent direct to headphones than through the HPA4. The HPA4, of course, is a fantastic amplifier but, perhaps, it was distorted by the interconnect cables (impedance issues), AC power noise (ultra low but still present) and bested by the SP3000M proprietary amplifier design.
So, it might be that the SP3000M (and its future ilk) is a giant killer: true audiophile sound quality with the convenience of portability and benefit of rational affordability. A testament to SOTA audio technology. I continue to listen and determine if a DAP will work for me long-term. BTW, stay tuned for the next release of PGGB-IT!, DSD upsampling is going through a revolution in ultra low noise modulators.