Considering the RS151

#1

Hi. I’m thinking about buying an RS151 and would appreciate input from those with experience of the unit.

I currently have a high-end set up (electronics by Gato Audio) but my wife finds the system hard to use. My preamp doesn’t have HDMI eARC, so needs to be set to the optical input to watch TV. I use Roon for music but Roon won’t wake the system from standby (the network board isn’t powered when in standby) so the preamp needs to be turned on and switched to the ‘NET’ input before Roon will work.

I have a Harmony remote control which makes this all possible and relatively painless, but my wife struggles to get it to work. And once the inputs get out of synch, she can’t fix it. The result is she doesn’t listen to music, which sort of defeats the purpose of the system.

I think the RS151 would be more user friendly. I would display a clock when in standby, I believe Roon would automatically bring the unit out of standby (please correct me if this is wrong), and eARC would also automatically bring the unit out of standby and switch to the correct input. I could then just use the TV remote + Roon remote for system control. This would make my wife happy.

Two issues concern me. First is the software bugs that most of this forum is devoted to. I think my use case is pretty straightforward and probably less affected than most - I wouldn’t use the Rose app often, for example (probably just for setup).

Of greater concern is sound quality. I’ll obvously have to spend time listening to the unit. But I probably would have bought it already if it wasn’t for the HiFi News review, whose measurements show a big jitter problem with the unit (and, in fact, with all HiFi Rose DACs). I haven’t seen much discussion of that issue on this forum but has HiFi Rose responded at all, or does anyone have a perspective they could share on this? Jitter has essentially been fixed in modern hifi, so if HiFi Rose has an issue that raises serious questions for me about their engineering prowess.

Apologies for the long post - thanks for staying to the end! I’d greatly appreciate any thoughts.

#2

Bails,

Is this what you were referring to?

HiFi Rose RD160 USB DAC Lab Report

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We have tested other implementations of the superb two-chip AK4191EQ upsampling/noise-shaper and AK4499EXEQ DAC [HFN May ’24] so a baseline has already been established. In practice, however, there are key aspects of the RD160’s performance that are determined by both the DPC (Digital Processing Core) and its balanced analogue output stage. The latter will deliver a maximum 8.8V from a 110ohm source impedance, rising to 258ohm/20Hz – HiFi Rose claims the RD160 has a particularly extended LF response but, in practice, there are a host of DACs flat to 2Hz. The A-wtd S/N is a spectacularly wide 120dB but distortion is analogue over the top 20-30dB of its range, from 0.0025-0.023% at 0dBFs down to 0.00015-0.0006% at –30dBFs [all 20Hz-20kHz, see Graph 1]. The real bugbear takes the form of a low-rate ±3Hz jitter amounting to ~50,000psec but that might be missed with cursory spectral analysis [see Graph 2 – grey spectrum = black spectrum magnified x35 on the X scale].

Otherwise, response and stopband rejection are determined by the choice of six digital filters, including two linear-phase (Sharp and Slow) and two minimum phase types (Short Sharp and Slow), though these are only enabled in ‘Bypass’ and ‘To PCM’ modes, not in ‘To DSD’ or in ‘Upsampling’ modes. The two sharp filters have the same –0.3dB/20kHz, –1.6dB/45kHz and –4.2dB/90kHz response with 48kHz, 96kHz and 192kHz media, respectively, with a similar 104dB stopband rejection. By contrast, the slow-roll off types trade a limited 8.5dB stopband rejection and –8.5dB/20kHz, –10.7dB/45kHz and –13.4dB/90kHz response for minimal ringing/time domain distortion. The ‘Low Short’ filter is a hybrid type that shows in-band ripples. PM

ABOVE: Distortion vs. 48kHz/24-bit digital signal level over a 120dB dynamic range (black, 1kHz; blue, 20kHz)

ABOVE: High resolution 48kHz/24-bit jitter spectrum comparing Bypass (black) with Upsampling (red). Zoom spectrum with mkrs (grey, x35, ±100Hz span)

Hi-Fi News Measured Specifications:

Maximum output level / Impedance 8.83Vrms / 258-110ohm (XLR)
A-wtd S/N ratio (S/PDIF / USB) 120.3dB / 120.4dB
Distortion (1kHz, 0dBFs/–30dBFs) 0.0025% / 0.00015%
Distortion & Noise (20kHz, 0dBFs/–30dBFs) 0.023% / 0.00063%
Freq. resp. (20Hz-20kHz/45kHz/90kHz) +0.0 to –0.3dB/–1.6dB/–4.2dB
Digital jitter (48kHz / 96kHz / 192kHz) ~50,000psec all sample rates
Resolution (1kHz @ –100dBFs/–110dBFs) ±0.1dB / ±0.1dB
Power consumption 15W (1W standby)
Dimensions (WHD) / Weight 430x88x330mm / 10kg

\ 10x30
\ 26x24COMPANY INFO

Citech Co., Ltd

South Korea

Supplied by: Henley Audio Ltd, UK

Telephone: 01235 511166

https://hifirose.com
\ 10x40 \ 10x1 \ 26x24ARTICLE CONTENTS

\ 10x2

Since I own one of these, I’d like to hear a response from the HiFi Rose moderators/support on this forum and how they intend to address the “bugbear” issue.

StandardModel

#3

Basically, yes. That’s the problem identified with the RD160. This is what HiFi News found re the RS151, which sounds like the same issue, suggesting it’s an engineering problem with HiFi Rose (it’s certainly not the dac chips themselves):

HiFi Rose RS151 music library/streamer Lab Report

While this new flagship player/DAC represents a further evolution of the DPC (Digital Processing Core) seen in the ‘1st gen’ RS150 [HFN Jun ’21] and more recent RD160 USB DAC [HFN Jan ’25], it also marks a departure from the AK4191EQ upsampling/noise-shaper and AK4499EXEQ DAC employed previously. Instead, the RS151 uses a single ES9039SPRO from ESS, maintaining its predecessor’s super low distortion with just 0.00007% at the top of its dynamic range [see Graph 1, below] and widening the A-wtd S/N from 119dB to 121dB here. The maximum 8.84V balanced output is more than sufficient to drive any power amp into clipping without the services of an intermediate preamp, but while HiFi Rose claims a low 3ohm source impedance, this is only the case above 500Hz – below this it rises to 935ohm/20Hz.

Unfortunately, the very low-rate jitter seen in those earlier HiFi Rose player/DACs persists in this new model, amounting to >20nsec and with a base modulation of ±2.65Hz in this implementation [see zoom jitter plot, grey spectrum, Graph 2]. Clearly this is not linked to the choice of AKM or ESS DAC, but is possibly an intermodulation between internal clocks. While numerically very high (via all digital inputs), experience suggests this very low-rate jitter may bring a marginal softening to stereo images and top-end ‘air’. Neither were any of the six digital filters enabled in our sample, every selection bringing the same slow roll-off minimum phase digital filter. This trades limited post-ringing for a poor stopband rejection at low sample rates (just 8.5dB at 48kHz) and roll-offs at –1.7dB/20kHz, –5.0dB/45kHz and –6.4dB/90kHz with 48kHz, 96kHz and 192kHz media. Fortunately, regular OTA firmware updates are offered! PM

#4

“Fortunately, regular OTA firmware updates are offered!”
If only.

StandardModel

#5

I’m not very technically minded, so I’m not sure whether this points to a software problem. The tester above guesses the jitter results from an ‘intermodulation between internal clocks’, which sounds to me more like a hardware/engineering issue. The filter problem does sound more like something that could be solved with software, if it was a priority.

#6

Hello,

So there’s a hardware problem with the RS151?

I’d like Hifi Rose to clarify this point.

Thanks,
Fred

#7

It would, at least it does on other RS devices.

If you are going to use it with Roon, at least so far, across multiple updates, that has been THE ONLY working fine.

While Rose DACs aren’t exactly top of the state of the art (and 160 decidedly mediocre), nothing actually audible there, as the use of meaningless hand-waving words like “air” shows.

#8

I agree with that and I may well not be able to hear the jitter’s affect on the audio output. For this sort of money I’m not expecting state of the art but I am expecting solid engineering (Eversolo has a similar typology, for example, and measures pretty much perfectly, according to reviewing sites). I would love it if another reviewer measured the RS151 and came out Eversolo-type figures - that seems a reasonable expectation given the price point.

And thanks for the information on the unit’s compatibility with Roon. Functionally, at least, this is the component I’m looking for.

#9

You’re welcome. So far, Roon has been working with the Rose (250 and 520) perfectly.

Well, these are DACs, and using off the shelf chips at that (not that fully custom jobs, like Chord, were objectively any better, but at least there is some effort put in you’re paying for), so one should expect state of the art and solid engineering for far less money than either Rose or even EverSolo want for their gear. In HiFi world, you generally get lower objective performance as you go up the price ladder. You are paying for “feelies.” At least Rose gives you a big screen.

#10

The big screen is very nice and what initially attracted me to the unit. It’s what’s behind the screen that’s making me hold off for the moment.

#11

Yup. Really, the big screen panel, which they get from Citech, is the only distinguishing feature. and it is neat. If the price is right, and you really like the screen, it does make for a neat Roon endpoint.

Sound-wise… you have to go more expensive to get something that’s audibly worse (PS Audio or something) by itself. However, in realistic setups, unless you’re rocking a nice pair of Magicos or something, a device with proper bass management (EverSolo, or Lyngdorf, or many NADs, or, really, even a Wiim) would sound better with far less hoop jumping.

#12

I’m starting to think that’s right. The price of the RS151 here (Australia) is only just below the NAD M66, which is probably a safer bet. There’s some new Cyrus gear coming soon that looks good too. I do like the RS151’s screen but I’m not convinced by the audio engineering behind the product.

#13

@Bails,
I made the exact same mistake and bought the RS151 mainly for the large screen. Six months later I can share a few observations:

  • If you use good third‑party software (Roon, etc.), the large screen becomes almost redundant.
  • I expected much more from a device at this price (parametric EQ, room correction, etc.), features that—according to HiFi Rose—won’t be added to the RS151.
  • Firmware and support are poor; I’d rate them 2–3 out of 10. The level and quality of support felt worse than what I’ve seen on AliExpress.
  • You’ve probably already noticed that the Rose Connect software is essentially unusable.

My recommendation: ask yourself what, besides the big screen, is actually better than competing devices. I cannot recommend HiFi Rose as a company, and I would not buy the RS151 again.

Just my two cents — other users may have different experiences, but I wanted to share my impressions and an expensive mistake.

2 Likes
#14

:clap:t2: :clap:t2: :clap:t2: :+1:t2:

:v:t2:

1 Like
#15

I own an RS151, and since the software update OS 5.9 - Rose OS 5.9.07 - Rose Main 5.9.07.1 - Rose Service 5.9.07.1 -, everything has simply changed for the worse. The most important thing about the RS151 was its sound quality and detail. With the new software version, the audio is just awful, and it’s become like something you’d find on a supermarket shelf. To top it off, HiFi Rose has the nerve to tell me through their official communication channels that the update hasn’t changed the audio quality. These people always underestimate their customers and think we’re all deaf and stupid. My suggestion is that you don’t buy an RS151. Eversolo products are getting very good reviews these days.

1 Like
#16

I believe your sediments regarding the audio quality…
I’ve expressed the same…
So what I’ve done is sent my unit back to Korea for evaluation…
It’s sad that there colleagues (MR ROSEHAN AND OTHERS) Are being quiet in regards …
I’ve asked these questions numberus times.
MoFi is ill equipped to determine any anomaly.
So when Mr KiHoon gets back to me I will post the results.

#17

Here the M66 is about $1500 more than RS151, but it’s probably still a better deal. Proper bass management (4 subwoofer outputs!), Dirac, and BluOS actually works.

IMHO, 250 and 520 are the only models that somewhat make sense, if you like the big screen. And Rose considers them “low end” enough that they do not cripple them by removing PEQ at least.

They certainly make for good conversation pieces, and I run New Year fireworks on the 520’s screen when we’re celebrating which is neat. But that’s about it. Sound-wise, it took quite a bit of effort fiddling with convolution filters and trying to integrate subwoofers through line outputs of 520 to make it sound as good as a significantly cheaper, non-master series NAD I had in its place before did…

1 Like
#18

@Steve_H
Thank you for your effort. Please keep us in loop. To be frank, I’ not expected more than the typical Rosehan polite, non‑committal (nonsens) reply.

#19

In case of 250 and 520 byside lower screen resolution, old display tecnology, low cpu power, still you would have the bad company and service. I’d would not recoment to anyone to go for that package in this price range.

#20

Perfectly sufficient for the purpose. If you are looking sat it from anything like a reasonable listening distance, higher screen resolution is totally irrelevant, and who cares what technology is used for the screen? The CPU is fast enough, too. It could even run reasonable room correction on it, if it were programmed by someone competent.

Service and software quality would be still Rose, of course.