Playback Speed Issue with Roon Nucleus One and Magnetar UDP900 + Eversolo T8 (ref#X8C827)

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1

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· When playing music with Roon Nucleus One using the Magnetar UDP900 MK2 as DAC, and Eversolo T8 is the Roon endpoint, the speed of music is faster and plays at a higher pitch. I notice this with 44.1 and 176.4 khz:


A piece of 4.40 minutes is turns into 4.17 min with 44.1 khz, and one of 5'29" turns into 5'01" with 176.4 khz.

Music at 192khz is OK.

Measured using a stopwatch.

It happens only when USB connection is used, not coaxial or optical.

When Magnetar is the endpoint, speed is normal. (no T8 involved)


Looks like a handshake, sample rate or clock synchronicity mismatch problem. I've already set and tried different configurations in Roon, Magnetar and T8, like 'resync delay' and 'clock master prioriry' with different values in Roon. No DSP (Muse, in Roon) is used. I did a factory reset and on-off several times. Connected/disconnected cables. Eversolo T8 Firmware is v1. 5.75. Will there be an update to address this problem in case it belongs to the T8?

Magnetar UDP900 MK2 is 1012CR-ESP01 May20.2026.

ROON Nucleus One is 2.67 (build 1661)

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2

Hey @Fernando_Machado,

Thanks for writing in and for sharing your report! We were able to review a fresh diagnostic report from your Roon Server and can confirm:

When playing 44.1 kHz-family rates (44.1 / 88.2 / 176.4), the T8’s USB output stage is actually clocking the audio at the corresponding 48 kHz-family rate (48 / 96 / 192). The DAC plays 44,100 samples-per-second of data at 48,000 samples/sec, so the music finishes 8.8% early and 8.8% higher in pitch, exactly your stopwatch numbers. The 192 kHz case is fine because 192 is already a 48k-family rate, so there’s no mismatch.

That said, it’s doesn’t appear to be every 44.1 playback, it’s intermittent, but when it breaks, it breaks by exactly the 44.1k→48k ratio. That’s a hallmark of the device’s USB clock domain failing to switch to the 44.1 kHz master clock and staying on (or falling back to) the 48 kHz clock. Note 88.2 didn’t appear in your test sessions but would behave identically.

Roon is doing everything correctly here. For every track it negotiates the right format with the T8 and sends the matching sample rate: sample_rate:44100 for 44.1, 176400 for 176.4, 192000 for 192.

The T8 accepts each one (“status”:“Success”). So this is doesn’t appear to be a Roon configuration or handshake problem on Roon’s side, Roon hands the T8 a correct 44.1 kHz stream.

It appears that the fault is inside the Eversolo T8’s USB output path. When it plays a 44.1 kHz-family rate, its USB audio clock domain is not switching to the 44.1 kHz master clock, it stays running at the 48 kHz-family clock and plays 44,100 samples-worth of data per second at 48,000 samples/second. That’s why:

  • It's 44.1/88.2/176.4 only (192 and 96 are native 48k-family, so no switch is needed → fine).
  • It's USB only (coax/optical use a different clock path on the T8 → fine).
  • It's independent of every Roon setting you've tried (resync delay, clock master priority, DSP), none of those touch the device's internal USB clock.
  • It survives factory resets and cable swaps.

The best next step here would be to get in touch with Eversolo to report this. Does this happen outside of Roon? We’ll share this with our partners team as well if so.

In the meantime, see if any of the below help:

  • Look in the T8's USB/audio output settings if there might be a USB Audio Class mode toggle (UAC 1.0 vs 2.0), a "native DSD/PCM" or DAC-compatibility option, or any per-family clock setting, and try the alternates.
  • Check whether the T8 has a global "resampling" or "fixed output rate" option that might be set to a 48k value; if so, turn it off (you want bit-perfect passthrough).
  • Test a different USB cable/port on the T8, unlikely given the pattern, but cheap to rule out.

Thank you! :folded_hands:

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Thanks for the answer and explanation.

I changed the USB Cable for a cheap one and it’s the same quick speed. (as expected)

The USB Output in the Eversolo T8 is set to ‘automatic sample rate’. There are choices from 44.1 to 768 khz on PCM section. Latency is set to 0. I tried other values.

I can’t find UAC 1.0 OR 2.0 option.

I copied your message to Eversolo. They promised to do tests based on the track I gave example of.

This one:

Thank you again

Fernando

4

Hi @Fernando_Machado,

Thanks for the update. That extra testing on your side, and with Eversolo, is very helpful.

Looking over the Eversolo T8 Manual, I would confirm you are on the latest firmware and it looks like there may be an Original Sample Rate Audio Engine setting, which may help:

Please keep us posted on what Eversolo replies about the track you shared. If they come back with anything specific, we can take it from there.

5

Hey, @Fernando_Machado.

Just checking in on this. Have you had a chance to confirm that the Eversolo T8 is on the latest firmware and look for the Original Sample Rate Audio Engine setting we mentioned? We are also still interested in what Eversolo says about the track you shared, since that may give us the next clue. Let us know what you find, thanks.

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Yes, firmware is the latest: 1.5.75.

I have not received further feedback from Eversolo, as they informed the would take a mall break. I’ll insist soon.

I’ve checked the menu you present. Most options are likewise, mainly the last one. Replaygain is off, too.

7

Turned the last option shown to off, and the quick speed continues.

8

Thanks for the additional information @Fernando_Machado! One follow up question for you:

Are you able to reproduce the issue when not using Roon as the audio source/player?

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Unfortunately I’m still waiting for an answer from EVERSOLO. They informed they had submitted the information to the research and development section.

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Hello @Fernando_Machado

Please keep us posted on any progress.

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No, only when the Roon endpoint is the T8, not the Magnetar.

Using the T8 (no Roon) with Apple ot Tidal Connect the reproduced speed is normal.

Suggests Roon’s fault through USB connection, because coaxial and optical are normal, (also using Roon) ?

12

Hello @Fernando_Machado

That’s a genuinely useful test, thank you. It doesn’t point at Roon though, if anything it narrows down where the problem lives on the T8.

Roon’s diagnostics already confirmed it sends the T8 the correct sample rate for every format, and the T8 acknowledges each one successfully, that part of the handshake is fine. Coax and optical are also fine when driven by Roon, it’s specifically the USB output to the Magnetar that has the issue, and only at 44.1-family rates.

What your AirPlay/Tidal Connect test tells us is that the T8’s own USB output hardware is capable of switching its clock correctly, since it does so under those other sources. That means the bug is specific to how the T8’s Roon-endpoint software configures that same USB output, different from how its AirPlay/Tidal Connect pipeline does it internally. Worth passing exactly that framing to Eversolo’s R&D team: this isn’t Roon mishandling the connection, it’s their Roon-integration code specifically mishandling the USB clock switch that their other input sources handle correctly.

Please keep us posted on what they find.