Sorry if OT, but since there are a couple of AH90 owners. Is it still only one base clock compatible when running in DSD Direct, or does it now support both 44.1 and 48 kHz?
I do not speak in any way for Gustard Audalytics. I have done some extensive research using Ai research tools. If a Member of the Trade from Gustard speaks up on this or the AH90 feed, is up to them.
Here is what came out of my research.
"As of the most recent,
specific evidence I can verify for the
AH90 in true “DSD Direct” mode (the special Gustard-provided firmware), it is
still effectively a single-base-clock situation: you should treat it as
44.1 kHz-family only for DSD Direct operation (e.g.,
DSD256×44.1), not “both families.”
Roon Labs Community+1
What “one base clock” actually means here
In digital audio you have two clock “families”:
- 44.1 kHz family: 44.1 / 88.2 / 176.4 / 352.8 kHz and DSD rates derived from 44.1 kHz (e.g., DSD64 = 2.8224 MHz, DSD256 = 11.2896 MHz)
- 48 kHz family: 48 / 96 / 192 / 384 kHz and DSD rates derived from 48 kHz (e.g., DSD64 = 3.072 MHz, DSD256 = 12.288 MHz)
When a DAC is designed to be “perfect” about this, it either:
- has two low-jitter oscillators (one for each family), or
- has a scheme that can switch the master clock cleanly, or
- uses sample-rate conversion (SRC) / internal reclocking in ways that may defeat the point of “direct.”
In
DSD Direct, the entire intent is to keep the chain “direct” (no PCM conversion, no unnecessary processing), which usually implies the device is
expecting a DSD stream synchronous to a particular clocking regime. If the firmware/clocking path is implemented around
one family, then feeding the other family either:
- forces some internal workaround (not truly “direct”), or
- produces instability/artifacts (noise, distortion, crackling), or
- is simply rejected by the device/software chain.
What we can actually confirm for the AH90 (not just in theory)
A credible user measurement/reporting chain around the AH90’s
special DSD Direct firmware explicitly states:
- “With the DSD Direct firmware … you must set HQPlayer to DSD256×44.1kHz … DSD256×48kHz results give loads of noise and distortion, so avoid it.” Roon Labs Community
That is exactly the “single base clock” behavior you’re asking about: it is not being described as “now supports both 44.1 and 48 kHz families,” but as “use 44.1-family; avoid 48-family.”
Separately, later thread commentary (late 2025) continues to frame AH90 DSD Direct as something that requires the special firmware and some know-how to install, but does
not introduce any verified claim that the AH90 has gained robust dual-family DSD Direct support.
Roon Labs Community
So, does it “now support both 44.1 and 48 kHz”?
There is no verified, up-to-date evidence I can cite that the AH90’s DSD Direct path has been updated to support both families cleanly. The most concrete, device-specific guidance still points to
44.1-family only and warns against 48-family behavior.
Roon Labs Community+1
Practical implications for you (HQPlayer/Roon use)
If you use HQPlayer with AH90 DSD Direct firmware:
- Set HQPlayer output to DSD256 (or your chosen DSD rate) on the 44.1 base (often shown as DSD256×44.1).
- For 48 kHz-family source material (48/96/192 kHz), HQPlayer will need to rate-convert it into the 44.1 family before modulation to DSD, so the final DSD stream stays in the 44.1-derived clock domain.
This is not just a “preference”; it is how you avoid the exact failure modes the reports describe."
From my experience: I have rather large number of DSD's collected over the years. I simply switch to DSD Mode and play them and they sound terrific on my system. I have the most recent firmware and am very happy. I have had several occasions when my SimAudio Moon CD-1 which was one of their first players, required I use a computer or over the network.
I hope this is a help.