New to me, bought off a good friend in immaculate condition.
I know it’s not the cool new kid, bee’s knees. But it started off sounding really superb. Moving to Roon Only mode brought a bigger uplift in sound than RO mode for my D2, which was already a readily apparent upgrade in SQ. Soundstage depth/width/height increased, clearer image delineation and tone, slightly stronger bass.
Just wanted to thank Lumin for making such superb units.
Are you applying 3M EMI absorber beneath those extra heat sinks?
I just used normal 3M™ Thermally Conductive Adhesive Transfer Tape 8711. But all heat sinks are aluminum (non ferrous).
Ah. I have a user who advocates sticking 3M EMI absorbers to chips, but I’ve never seen this practice outside my local forums. So I thought you were doing this. I assume this may have less (if any) effect on an A1 because the analog board and digital board are separately shielded by the aluminum chassis.
I have heard the same, but not yet experimented with that. I’ve seen it used on FPGA’s, processors, XMOS chips, etc.
I doubt the heat sinks affected the sound at all. Those are placed for longevity and heat management; drawing heat out of the ICs and the board (and into the beautiful, billet aluminum chassis).
However, the ribbon-cable ferrites made some really nice improvements in space, dynamics, tonal purity, air, and blackness. Further, there is now zero audible difference between screen-off & screen-on, whereas before it sounded subtly better with the screen off. This is great, because I love having it on. 
Also, though the A1 only has RJ45/100mbps, I threw in an EMO Systems en-85e network Isolator (the best for network audio, per EMO) and WHEW! Big bump in performance!
I’ve used one on my Nucleus+ for a year now and it has been great, but I see that providing isolation and noise reduction at each endpoint also has distinct benefits.
Never used fiber for audio, and the A1 lacks an SFP port, but the improvement is obvious and welcome.
SQ update.
I have been reading through multiple threads on various forums about the A1 and the WM8741 DAC chipset “preferring” DSD because that was its native internal format.
However, I had not experienced a positive result with Roon upsampling to DSD64 until today.
Upon reading the Wolfson WM8741 data sheet, I discovered on page 26 how to enable true ‘DSD Direct’ mode where:
“In DSD Direct mode the internal digital filters are bypassed, the input bitstream data is subjected to the minimal possible processing and is applied directly to the switched capacitor stage of the DAC system. Using this mode provides the purest possible representation of a DSD stream.”
Making a logical inference, I realized that I had enabled the DSD Post Filter setting in the Lumin App prior to moving into #ROONONLY mode.
After a quick device reset, I de-selected the Lumin DSD Post Filter setting (selection = ‘off’). Disabling all other non critical functions, then jumping back into Roon Only mode, with a Roon DSP 30khz DSD output filter, it was time to test.
WHOA. Upsampling to DSD64 via Roon DSP now brought a good degree more tonal insight, reverb tails seemed longer, soundstage slightly larger, everything a bit more detailed AND a bit more analog.
Okay, now I get this DSD thing for the WM8741 units. Now this makes sense. I had been running the WM8741 DAC chips in ‘DSD PLUS MODE’ by having the Lumin’s onboard DSD post Filter enabled and not the purest ‘DSD DIRECT’ mode.
For that DSD64 direct playback, you also need to set Volume Control to OFF in Lumin app (Roon should show “Volume control is fixed”), in addition to turning off Ultrasonic Filter. (A1 / T1 / D1 / D2).
What DSD upsampling settings are you using in Roon DSP? Smooth/Precise, Linear/Minimum Phase?
Correct, Lumin volume control and LEEDH are both off. Volume setting is at “100” and in fixed state. Roon shows volume as device controlled and ‘fixed’.
I’m using the following settings:
