[delirium]

I wouldn't let me prescribe from someone else what's «Distrubing» – that's something I can best judge on my own.

Music isn't noise. It can be peceived as comfortable to the ears up to much higher loudness levels than street or construction noise. It all depends on the quality of the sounds. Harmonic distortion is harmful (as the term already tells), the same goes for resonances with strong peaks that may appear with cheap speakers and headphones, but less so with more expensive/good ones.

Newer studies come to conclusion that the harmfulness of loud volumes with listening to music has been overrated in the past. I would say as long as you / your ears feel comfortable, you're safe. Do not rely on measurements, they can only measure so much, and if you additionally rely on outdated scales, you obstruct your musical enjoyment.

Be careful with volume....when you go on
antibiotics...it’s poisen to the ears...the normal
defense is down it’s not a joke.

 

[delirium]

If that app is typical of the ones you can download for smartphones, then its accuracy is not to be trusted, until it's been calibrated against a reference (which the app makers do recommend you do and usually supply an adjustment option).
The decibel app on my smartphone displayed several dbs lower than that of my hardware decibel meter (itself probably not that accurate in the first place) - the difference big enough to result in long term hearing damage.
I can't remember the exact difference now, but t was somewhere in the 10-20db region.

So, its fine to use such apps for relative volume differences, but not good enough if you want to protect your long term hearing (says he with mild tinnitus and so more concerned about such things).

Loudspeakers are pretty safe....but headphones.....be careful.

 

[miketlse]

Well...
looks like you can make
your own
m-scaler

@mlxx has made some interesting posts (like the one you quote) on the subject, and they piqued my interest to try and understand the mathematical/coding challenge behind these upscaling discussions. I have posted briefly in an attempt to improve my understanding based on one of the links that was provided.

As mlxx points out 'With a 44.1kHz song that is 4 minutes long, it would have 10,584,000‬ samples and we would need that many overlapping sinc functions.
They would need to be long enough to cover the entire song and we would need to wait for all the samples before we reconstructed.
This isn't practical, so we have to truncate the sinc function and do the reconstruction over smaller time periods with a smaller amount of samples.
How you do this and the precision of the calculations affects the reconstruction and the sound quality (this is where WTA plays a part).'

Rob has posted that it took him 10 years to perfect the WTA algorithm, which he has then used in his dac designs for the subsequent 20 years. Rob has also posted that it is possible for anyone to code an upscaler, but the difficult part is to develop an algorithm equivalent to truncating the sinc function and performing the reconstruction over smaller time periods with a smaller amount of samples - plus keep all the data in the samples aligned and in sync.

As I mentioned, my interest was triggered to explore the upscaling topic this winter, but I am keeping in mind a quote by Einstein 'if someone gave me an hour to produce a solution, I would spend 55 minutes understanding the problem, then 5 minutes on the solution' - the 55 minutes took Rob 10 years, so I am under no illusions that I am only a few microseconds into that 55 minute period.

To summarise, yes you can code your own upscaler, but do not expect it to be an overnight task to match the performance of the MScaler.

 

[dmance]

@miketlse

Jussi (HQPlayer)comes very close to the implementation quality needed to be WTA 1 comparable. I've done many hours of A/B using his latest ( just released) poly-sinc-long-lp filter. Not only is it a perfect match sonic signature, it's got way more bit resolution than 16-bits.

 

[nomad777]

lol... make your own mscaler ... I guess I could also make a Ferrari at least it would look like one...

I'm listening to the HMS as I type this. Having owned both the blu MK2 and the HMS I can say the HMS is superior. More detail , smoother, timing. Some claim they don't hear any difference. Again don't know how that's possible again I'll point to their setup.

See Audio bacons review and his thought and HMS vs Blu2

https://audiobacon.net/2019/05/31/chord-electronics-hugo-m-scaler-review-digital-disruption/9/

 

[rkt31]

@miketlse

Jussi (HQPlayer)comes very close to the implementation quality needed to be WTA 1 comparable. I've done many hours of A/B using his latest ( just released) poly-sinc-long-lp filter. Not only is it a perfect match sonic signature, it's got way more bit resolution than 16-bits.

Rob's FPGA's uses all it's processing power in real time while hq player can run on a decent i5 or i7 processor in real time. If hq player is giving more bit resolution, does it mean FPGA used in HMS is less powerful than i5 or i7 processor or Rob's algorithm is using more processing power and still giving less bit resolution ? Imho if it was so easy, rob wouldn't have required a FPGA.

 

[miketlse]

Rob's FPGA's uses all it's processing power in real time while hq player can run on a decent i5 or i7 processor in real time. If hq player is giving more bit resolution, does it mean FPGA used in HMS is less powerful than i5 or i7 processor ?

Always remember that Rob uses the capability of the FPGA to perform parallel processing, and keep all the data streams in sync.
A simple i5 or i7 performs serial processing, so Rob has pointed out that this makes it difficult to keep all the data streams in sync, and so potentially introduces errors. One way to negate this is for the i5 or i7 to delegate all that processing to a graphics card that can perform parallel processing (eg CUDA enabled).
So just comparing the FPGA chip to i5 or i7 processors is too simplistic an approach, because this does not consider how the data streams are handled.

 

[dmance]

Rob's FPGA's uses all it's processing power in real time while hq player can run on a decent i5 or i7 processor in real time. If hq player is giving more bit resolution, does it mean FPGA used in HMS is less powerful than i5 or i7 processor or Rob's algorithm is using more processing power and still giving less bit resolution ? Imho if it was so easy, rob wouldn't have required a FPGA.

PCM to PCM upsampling is far less burdensome to compute than PCM to DSD modulation.

HQPlayer PCM to PCM is performant on a Core i3. And yes, a modern CPU runs rings around an FPGA. Some digital experts know FPGAs some know x64 instruction sets. Also, CPUs have access to extended precision 80-bit floating point vs FPGA 64-bit precision.

I'm so convinced of the benefits of software upsampling dominating that ive staked my commercial reputation on it.

 

[miketlse]

I'm so convinced of the benefits of software upsampling dominating that ive staked my commercial reputation on it.

Well at least that clarifies that in my mind, that there is no potential for bias of any kind in your posts.

 

[dmance]

@miketlse
Mike - everyone has an agenda but in this world, even on this forum, there is such a thing as altruism - an honest desire to help fellow music lovers better understand their systems and the ways to obtain the best from it.

 

[Drewligarchy]

Anyone have any idea why this battery wouldn't work with HMS? Any chance it could damage it based on how it's described?

https://www.bhphotovideo.com/c/product/1493829-REG/omnicharge_op2qa002_omni_mobile_25600_mah.html

Also, what is the ideal voltage for HMS? I "think" I saw Rob say in his preso (or elsewhere is a post) it was 9-15. Are there any differences, or as long as you are in this range you are good? This is variable but would have to be set on 12 or 16?

I could order a PowerPilot from Amazon, but B&H is physically close to me so I could easily buy pop in and buy it. That said, I think Rob uses the PowerPilot - so if there is any chance it will screw up the HMS - I'll just order from there.

 

[miketlse]

@miketlse
Mike - everyone has an agenda but in this world, even on this forum, there is such a thing as altruism - an honest desire to help fellow music lovers better understand their systems and the ways to obtain the best from it.

Yes, but posters have been quite happy to claim 'well he would say that' about Triode and cables, and Rob and his dac designs, and now they will be able to suggest the same about your posts about software upsampling.
That is a fact of life, once anyone initiates a commercial interest in a product, and there will always be questions about potential bias.
You may well have 'an honest desire to help fellow music lovers better understand their systems and the ways to obtain the best from it', but all your potential customers on head-fi and elsewhere, will be the ultimate judges.

 

[miketlse]

Anyone have any idea why this battery wouldn't work with HMS? Any chance it could damage it based on how it's described?

https://www.bhphotovideo.com/c/product/1493829-REG/omnicharge_op2qa002_omni_mobile_25600_mah.html

Also, what is the ideal voltage for HMS? I "think" I saw Rob say in his preso (or elsewhere is a post) it was 9-15. Are there any differences, or as long as you are in this range you are good? This is variable but would have to be set on 12 or 16?

I could order a PowerPilot from Amazon, but B&H is physically close to me so I could easily buy pop in and buy it. That said, I think Rob uses the PowerPilot - so if there is any chance it will screw up the HMS - I'll just order from there.

Rob has posted to set PowerPilot to maximum of 12V for the HMS, because there is an input protection diode that will fail at less than 16V, and Chord will use it as the criteria when assessing warranty claims.
https://www.head-fi.org/threads/hug...official-thread.885042/page-166#post-14574188
https://www.head-fi.org/threads/hug...official-thread.885042/page-228#post-14613575

 

[Drewligarchy]

Rob has posted to set PowerPilot to maximum of 15V for the HMS, because there is an input protection diode that will fail at less than 16V, and Chord will use it as the criteria when assessing warranty claims.
https://www.head-fi.org/threads/hug...official-thread.885042/page-166#post-14574188
https://www.head-fi.org/threads/hug...official-thread.885042/page-228#post-14613575

Thanks. Just want to make sure I understand correctly. Based on the posts Rob says to set to 12V. Therefore, did you mean the input protection diode would fail at more than 16V (Rob said in one post to set to 12, and in another that 15 is the max input rating).

In other words, 12V is safe?

 

[nomad777]

Rob has posted to set PowerPilot to maximum of 15V for the HMS, because there is an input protection diode that will fail at less than 16V, and Chord will use it as the criteria when assessing warranty claims.
https://www.head-fi.org/threads/hug...official-thread.885042/page-166#post-14574188
https://www.head-fi.org/threads/hug...official-thread.885042/page-228#post-14613575

No ! set it to 9V or 12 V not 15V..... that is Rob's recommendation