Sorry, but what is K2?
You said
“it’s clock could be better”.
K2 is the Gustard clock.
In order to provide an accurate clock signal, the A26 features the ultra-low noise K2 module. This ensures that the DAC is able to achieve a very low jitter level for the most transparent sound possible.
The A26 also provides a 10M BNC input allowing it to be used in conjunction with an external clock generator.
Ahh, yes, I have spent about 12 hours measuring A26.
It is not particularly ultra low noise:
That widening of the main lobe base is phase noise from the clock. This is through USB input.
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And from lan input ? It’s the best input for HQPlayer even i saw, you used a HOLO Red on USB.
I have not tested it yet, as the switch on the equipment rack is out of ports, all 8 ports in use.
At some point I’ll try it out, and also with I2S from Holo Red which would slave the clock to Red’s clock.
Yes, I also tried the same UP Gateway used for that Holo Spring 3 measurement, but the results didn’t change in any notable way.
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A new (streamer) firmware for the A26 is out A26_Gustarender_1v41_onlyA26_A26only
1. Fixed known bugs.
2. Optimize memory consumption.
3. Upgrade upmpdcli to [1.7.7].
4. Upgrade HQplayer NAA to [4.4.0-56].
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I wish they would update also the DAC controller firmware… I don’t think this is related to the DAC chip controls.
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They seem to be relatively reactive (I’m following a French forumner’s worries with UPMP).
There is a way to objectify the lack of impact of DSD filters ?
On the R26, they released a controller firmware but the improvements were more on the display.
DSD256, with “narrow” setting:
DSD256, with “wide” setting:
I cannot really see any notable differences in the DAC wideband output between the two settings. And not what I would expect comparing to the values stated in the datasheet.
Depending if the 4499EX is running at 5.6/6.1M rate or 11.2/12.3M rate, there may be only one value for DSD512. But it should work for DSD256.
Now it is not documented anywhere which of the two fixed rate families they use. But I suspect 5.6/6.1M.
P.S. It would be nice if they would offer also menu option to select the modulator as well, 4191 has configuration option to choose from (IIRC) four modulators when used with PCM inputs.
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Picked up an ifi Micro iDSD Signature and haveing an issue getting DSD 512 via HQPe v.5, always outputs DSD256. The ifi is attached USB to RoPieee running the latest version, NAA enabled, and sourcing from ROON to HQPe.
Here is my setting for HQPe:
Here is the output from ROON:
What am I missing, ifi firmware and/or HQPe configuration?
Thanks
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Yup, I am reading and checking that now…
Thanks
@jussi_laako new Sabaj A20D 2023 features AKM AK4499EX - and no IMD hump.
Quite exceptional measurements in PCM. Sabaj is SMSL sister company.
And DSD Direct mode per the user manual, with 2 selectable DSD filters
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Does it actually work?
Ha well SMSL engineers fixed the issue I reported , quite quickly, with D-6.
If they remembered this bug, it should work.
Will wait for sales later and test out.
This AKM chip is best run at DSD256 right ?
SMSL D-6 worked fine at DSD256 - only DSD512 was the issue with 4493S
Depends on how it is being configured. I don’t know yet about DSD Direct mode. In other cases it is best run as high sampling rate as possible.
This new chip combo is very very different from the earlier ones. And completely different converter architecture. 4493 is still switched capacitor converter just like all earlier AKM chips. 4499 is switched resistor array converter, where they moved over to a different converter architecture.
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If it is on sale or available used at end of the year I’ll check it out
But to be honest I’ve gotten bored with USB DACs
I’ve got ethernet input DACs now with headphones setup and DSP XO active speakers (I converted some excellent KEFs to actives).
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Which ethernet DACs?
With headphones, an RPi4 running NAA OS with InnoMaker DAC Pro HAT. All in a nice and tiny aluminium case. Balanced outputs to an amp that has 47k ohm input impedance (higher is fine too).
With DSP speakers, Merging Anubis. Also a compact case. 4 balanced outputs to speakers and 2 unbalanced outputs to subwoofers.
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