@tjag The modded GAN1 as better than the Benchmark pre + amp in more qualities than the Benchmark was better than the GAN1. That was with my KEF LS50 Meta (soon to be upgraded to the KEF Reference 1 Meta). I sold 1 Benchmark AHB2 to someone who has some new horn speakers that are 118 DB sensitive. My guess is that I would prefer the BM stack with his horns over the GAN1. So it depends.
I would say that the modded GAN1 is very close to my Benchmark LA4 preamp + CODA #16 + Lumin X1 DAC/streamer. I think the modded GAN1 is almost as good but the slightly better stack cost so much more. The CODA amps has more power and that shows up in a very audible way, It is close sonically though with my not so difficult to drive speakers.
The GAN1 is a first gen product, while sounding amazing it is hard to use. Easy with my Lumin X1 but not so easy or as high quality with other streamers, The future products of this same design should be very interesting.
You would keep the DAC separate from the amplifier for the simple reason that DACs have been under continuous improvement over the last 40 years and many of them have decent volume controls in them these days so a preamp might not be needed. Of course, class D amps have seen vast improvement in the last 50+ years too!
Only DAC that I have heard that can approach the volume control of the Benchmark LA4 ($2500) was the Lumin X1 and even that Leedh volume control was not as good as the LA4 at low volume. The volume increments at low volume was not as linear or consistent as with the LA4 (nitpicking for sure).
From my perspective, the only standalone DAC tech that is really different (or evolving) are FPGA designs, I plan on using the LA4 preamp + CODA #16 + FPGA DAC in my Livingroom system, Only reason the GAN1 won't b used there is because of ease of use and I need a lot of power for KEF Blade 2 Meta.