PC to Neumann KH-120 mk ii

[BIDTheGreat]

I have purchased a Neumann KH 120 mkii pair of speakers today, with a pair of Audioengine HD5 on the way as well.
I got 'em both, and I'll sell one off when I decide which is best.

Anyway, I wanted to use a cheap USB-A to spdif-coax digital-to-digital cable to hook them up to my computer.

I also considering using a cheap little box called a DSD tech USB to CoAxial SpDif digital-to-digital convertor for $43 AUS.
I have USB calbes, and 3m 75-ohm RCA cables.

Is this possible?

And which USB-A to spdif cable/box should I use (no $500+ cables boxes, please)?

 

[DWPress]

Yup, you need a DAC. The Neumanns are kinda nice so you might want to get something that might cost slightly more than $43 (but not necessarily) and is proven to be transparent. Just check Amir's review index here and anything in the upper middle range tier+ that has the features you need (simple USB to optical or coax). Topping has gobs of them reviewed here and should be readily available in Australia.

The cables you already have are just fine as long as the RCA is properly shielded.

 

[somebodyelse]

Yup, you need a DAC.

No you don't - no conversion to analog necessary before the KH-120ii.

 

[Count Arthur]

How about one of these?:

S.M.S.L PO100, PO100 PRO & PO100 AK - Measurements (Digital Interfaces & DAC)

S.M.S.L PO100, PO100 PRO & PO100 AK Measurements Hey folks, It is time for my very last review of the year. A very special one, as there are three products to be measured today ! S.M.S.L released earlier this year the PO100, a tiny and fairly cheap USB to S/PDIF interface. Later in 2022...

www.audiosciencereview.com

 

[DWPress]

No you don't - no conversion to analog necessary before the KH-120ii.

Didn't look up the specs but should have known there was a digital input on the Neumann's.

 

[staticV3]

Persoally, I'd buy an SMSL PO100 2024, if and only if, I was playing exclusively from Windows or Android, and had no use for ASIO or Wasapi Exclusive.

Reason being that when used with macOS or iOS, due to the fact that the PO100 2024 lacks support for UAC2 hardware volume control, the default systemwide volume control is locked to 100% volume with no way to adjust.

No issues on Windows or Android since they use software volume control that doesn't depend on specific USB features.

On Windows though, using ASIO or Wasapi Exclusive disables software volume control and similarly makes OS volume locked to 100%, unless the DAC/DDC supports UAC2 volume.

The majority of inexpensive USB to SPDIF converters likely work the same way.

 

[BIDTheGreat]

Thanks go to Count Arthur and staticV3 for the advice.
I have a little red DSD Tech ("USB to TOSLINK 96K 24Bit Coaxial SPDIF Audio Adapter Support"), which is a little red box, but similar in appearance to the ones listed above. It is being delivered by mail today, and I just hope it performs OK.
I will eventually get a better one with a volume control at some point, but I want to research it: I want to get a box that does only USB or TOSlink to digital Coax spdif only without XLR as the latter would waste my money.

Staticv3: I kinda know what a ASIO or Wasapi driver is (I have Windows 7 and stubbornly refuse to upgrade).
But is the "Exclusive" any different? I wanted to use my Corsair K-70 RBG Pro keyboard volume Roller to control the volume (essentially the windows main volume) and I hope I can do that as I need to turn them down low at times.

What is this "Exclusive" mode, and how can I tell which mode I have (I know, I am a bit of a noob)?

BTW, I was going to get the Neumann KH-150 with an RME ADI FS DAC, but they were out of stock, and so I got the KH-120 mkii's as they were in stock on the day.
But I got a price-match quote from DJ City (and from Turramusic) for $4398 Australia for the pair of KH-150's [without the MA 1] and $1, 299 for the RME ADI-2 FS DAC - not bad.
This offer lasts until 28 Feb this year, guys, so anyone interested so act now!

 

[staticV3]

What is this "Exclusive" mode, and how can I tell which mode I have (I know, I am a bit of a noob)?

ASIO and WASAPI are specialized Audio playback APIs for Windows.

WASAPI comes in two flavors: Shared and Exclusive.

It is a special attribute of ASIO and Wasapi Exclusive (and technically also Kernel Streaming which is largely obsolete), that they bypass all Windows processing, which includes APOs for signal processing as well as software volume control.

Here's a diagram that may help:


When you use regular "dumb" DACs, then that means that as soon as you enable one of these playback APIs in your playback software (sometimes called by name, sometimes simply "Exclusive mode"), the Windows volume control/slider ceases to function and you get 100% full-blast volume at all times, unless you set Windows to zero at which point the output is muted.

Only the Windows volume is affected by this, so if your playback software has its own, internal volume slider then that will continue working regardless of the chosen API.

At least on modern versions of Windows (10 is the oldest I've ever used so not sure about 7), the OS will detect if the selected USB DAC supports UAC2 hardware volume control, in which case the default volume slider will switch from controlling the volume internally inside the OS, to sending volume commands alongside the audio signal to the DAC, which then applies the volume control/reduction on the DAC chip.

This happens automatically and without any indication to the end user.

Except for the fact that when UAC2 hardware volume is in use and volume control no longer depends on the internal OS processing, it will work exactly the same at all times, regardless of which playback API your software is using and regardless of whether Windows processing is being bypassed or not.

 

[BIDTheGreat]

OK, yesterday I got my DSD USB to TOSLINK 96K 24Bit Coaxial SPDIF Audio Adapter.
Very professional EBay seller (yofela), who got me this in under 24 hours to my door from Interstate - if only all EBay dealers were so great!

Anyway, I notice the SNR is only 100dB and the Dynamic Range is only -94dB ... while it is a "does the job" unit (for now), is that going to bottleneck the audio quality from my Neumann KH-150 mkii speakers ... according to Google AI it doesn't ebcause I am only using it as a digital pass-thru kind of thing.

But I doubt Google AI knows anything.

Furthermore, my USB ports are a bit noisy and problematic.

Suggestions from Count Arthur are already noted ... just want to spend ages to make sure I get the best one - this DSD one is a $50 temporary cheapo one.

I have a good TOSlink port on my computer ..., am I better off getting a TOSlink to Spdif-coax converter - and if so - what quality/price-range do I need?

Or does the DSD one get the full sound quality anyway and just keep using it forever?

 

[BIDTheGreat]

Oh yeah .. I almost forgot.

The Neumann KH-120 mkii using the DSD USB to TOSLINK 96K 24Bit Coaxial SPDIF Audio Adapter doesn't sound as I expect.
I've never heard the Neumann kh-120 mkii before ... but I compared it to an old and damaged Audioengine A2+ and besides the greater presence, bass and body, I can barely tell them apart. With the treble, I have to sometimes check if I've got the A2+ selected or the Neumann KH-120 mkii.

Perhaps this is the bottleneck from the DSD converter box?
I don't want a DAC as I want to keep the signal chain pure and not convert to analogue before the KH-120's just convert it straight back to digital for the DSP.
Help!

 

[BIDTheGreat]

The Lindy SPDIF Digital / TosLink Audio Converter (Part No. 70411) might be a possibility.
I'd rather use my TOSlink port as my USB ports are a bit noisy.
$139 AUS from the Lindy website.
I've tried searching the AudioScienceReview website, but I can't find any measurements for this.
Google AI claims a Dynamic Range of 142dB - I doubt it.

Is there anyone on ASR who has tested this unit independantly?

 

[somebodyelse]

OK, yesterday I got my DSD USB to TOSLINK 96K 24Bit Coaxial SPDIF Audio Adapter.
Very professional EBay seller (yofela), who got me this in under 24 hours to my door from Interstate - if only all EBay dealers were so great!

Anyway, I notice the SNR is only 100dB and the Dynamic Range is only -94dB

Where did you get those figures from? They make no sense. It's converting from one digital format to another, with the bit rate and sample depth unchanged. It just needs the output to be within spec for timing and level.

while it is a "does the job" unit (for now), is that going to bottleneck the audio quality from my Neumann KH-150 mkii speakers ... according to Google AI it doesn't ebcause I am only using it as a digital pass-thru kind of thing.

Unless the USB to SPDIF adapter is grossly defective, Google's AI is correct. Inside the KH-150 the signal will go through ASRC to match it to the internal DSP sample rate, bit depth and probably clock domain. This makes it relatively immune to jitter so long as it's not bad enough to lose lock on the signal. That said, some people have reported skips that seem like loss of lock, and I don't think a definitive cause has been found - maybe I missed it.

 

[BIDTheGreat]

Where did you get those figures from? They make no sense. It's converting from one digital format to another, with the bit rate and sample depth unchanged. It just needs the output to be within spec for timing and level.

Unless the USB to SPDIF adapter is grossly defective, Google's AI is correct. Inside the KH-150 the signal will go through ASRC to match it to the internal DSP sample rate, bit depth and probably clock domain. This makes it relatively immune to jitter so long as it's not bad enough to lose lock on the signal. That said, some people have reported skips that seem like loss of lock, and I don't think a definitive cause has been found - maybe I missed it.

I got the figures from Google AI. They are MUCH lower than the D-Range and SNR of the KH-120 mkii's and so I speculated that a better unit would provide better quality.

I agree that jitter and clocking is certainly not a concern - but could the DSD USB-to-Coax bottleneck the KH-120 mkii's given their (according to Google AI) low D_Range and SNR spec? Perhaps the Lindy one w/ TOSlink might be better, or a better converter [I do NOT want a DAC for this setup].

 

[somebodyelse]

I got the figures from Google AI.

Halucination/conflation then - those figures have no basis in reality, which is why I wondered where they came from.