Replacing HDMI audio converter with decent DAC but need to retain volume control from casting app.

[jv99]

Current setup:
Roku streaming box with only HDMI output. The box streams music from it's own YouTube app; I also use the YT app on phone as a casting remote control so I can adjust volume, switch tracks, etc at a distance (all via wifi... there's no bluetooth awfulness involved!)

I have Roku box -> HDMI Audio Converter (Extractor) -> RCA line out to a nice vintage stereo amp and floorstanding speakers.

It works but the sound is bad (thinner, more distortion) than my previous, now obsolete, Roku box that had a built in analog output that went straight to amp... because I'm forced to use a crappy junk HDMI converter I bought, link here:

HDMI Audio Extractor Converter HDMI to HDMI & Optical SPDIF + RCA L/R Stereo | eBay UK

HDMI Audio Splitter Extractor: [Upgraded 4K@60HZ version] avedio Link HDMI to HDMI Audio Extractor Converter can extract audio from digital HDMI signals to amplifiers, Soundbar, speakers, etc. via optical SPDIF or RCA L/R stereo audio output.

www.ebay.co.uk

What to do? I looked at both SMSL PS100 which is a close replacement (minus the HDMI output which I don't need.) however it doesn't rate highly versus the SMSL SU-1 which I'd prefer to buy. The problem is the SU-1 has no HDMI input.... So I could either:

1. Keep the crappy HDMI converter purely for a HDMI -> Optical/Coax conversion and then connect that into the SU-1; now aside from questions about introducing potential jitter/digital degradation from this junk.... I believe I would totally lose the volume control would I not? I heard the Opt/Coax do not support it like HDMI direct to the DAC does? Or am I mistaken?

2. I buy a HDMI -> USB-C converter/cable and run that direct into the SU-1 from the Roku box.... but I thought the SU-1 also requires power via USB-C which HDMI can't provide can it? Or can I get a HDMI -> USB cable that can inject additional power?

If the above two options aren't possible what can I do?! I need digital/source volume control because I sit at the far end of the room often with a keyboard on my lap; and between song uploads the volume can vary on YT hence I need tap on my phone regularly to adjust it. I don't want to replace my amp and I'd rather not have to spend £60+ on some DAC that comes with its own remote control which is more clutter and less convenient to have to use two remote devices, one for track switching (phone app) and another dedicated remote control just for volume!

It looks like I'm stuck with the PS100 then, or is there some viable way to use the SU-1? Also I realise YT is not Tidal, or even full CD quality but some uploads on certain channels are in very good quality so perhaps a SU-1 would noticeably improve the sound over the PS100 right? Also if I stream lossless from the Roku which I do much less often, then it would surely matter.

Any advice is greatly appreciated, thanks

 

[staticV3]

I believe I would totally lose the volume control would I not?

You'll still be able to control volume from your phone, even with Optical output.

Volume being locked with Optical out only refers to TVs with their native Apps.

I buy a HDMI -> USB-C converter/cable and run that direct into the SU-1 from the Roku box

That doesn't work.

The SU-1 is a USB accessory and can only receive USB audio from a USB host device (computer, phone, SBC etc.)

A HDMI->USB-C converter cable is also a USB accessory and cannot feed the SU-1.

BTW, the PS100 also wouldn't work in the way you think.

It has an HDMI ARC input, not a general purpose HDMI input.

It can only be connected to an HDMI ARC output. These are commonly found on TVs and AVRs.

The Roku stick has a general purpose HDMI output.

 

[jv99]

Many thanks for your reply! Seems I got it totally wrong then; I thought option 1. was not possible but the other options would be!

But I'm still confused about the HDMI ARC thing. I thought that an HDMI ARC input was just a normal HDMI input accepting digital audio without the video part ...so I thought any HDMI output that contains audio data would work?

Are you saying that the audio from a normal HDMI output is carried differently to the audio from an HDMI ARC output?! Because then that would equally suggest that any ARC output (say from a TV) cannot work with any standard HDMI input (if you just wanted to play the audio via the AV device's standard HDMI input.)

((p.s. ..If that's true, then surely for compatibility reasons why invent ARC at all just to save on a separate HDMI port?! What a mess How many people will just buy the device, then discover it doesn't work as expected and then have to send it back...))

 

[JSmith]

Are you saying that the audio from a normal HDMI output is carried differently to the audio from an HDMI ARC output?!

Correct... HDMI ARC reuses one of the HDMI pins for ARC instead of regular audio/video.

So the DAC is expecting ARC audio only on that pin, not the full HDMI stream. If you plugged it in and sent audio/video nothing will happen.

When a DAC has an ARC input it isn't just sitting there listening for any HDMI audio, it's waiting for a handshake initiated by an ARC enabled TV via CEC. eARC is a bit different again...

Best to use the digital outs on your HDMI extractor (or replace it if poor) run that to a DAC that has digital volume control and a remote.


JSmith

 

[jv99]

Hey thanks so much JSmith and staticV3 for your replies. I was about to order an SU-1 and toslink cable but I just read your last line again:

"Best to use the digital outs on your HDMI extractor (or replace it if poor) run that to a DAC that has digital volume control and a remote."

Sorry if I misunderstood the the last part... staticV3 says I will be able to adjust volume using my phone just as I currently do and introduction of an optical cable won't affect this. This is important because SU-1 does not have a separate remote control for volume. Is this what you mean? Or do you disagree with staticV3?

 

[staticV3]

But I'm still confused about the HDMI ARC thing. I thought that an HDMI ARC input was just a normal HDMI input accepting digital audio without the video part ...so I thought any HDMI output that contains audio data would work?

No. An HDMI ARC input can only receive audio from an HDMI ARC output.

Similar to how a USB accessory can only receive data from a USB Host.

 

[phofman]

why invent ARC at all just to save on a separate HDMI port?!

Audio Return Channel alllows sending audio from HDMI video sink - TV to HDMI video source - the AVR, so that TV sound can play on the nice audio speakers connected to the AVR. It conveniently uses the HDMI cable already between AVR and TV for viewing movies on the TV (and audio through AVR speakerrs). It's called return channel because the audio goes the opposite way than HDMI direction.

Since HDMI stream is one way, ARC uses a different technology than HDMI (similar to SPDIF), using a pair of wires in the HDMI cable which was originally designed for other features.

 

[jv99]

Thanks for the explanation! So if that is what HDMI ARC is.... what is the "HDMI I2S port" on the SMSL PO100 for?
Does HDMI I2S accept a normal HDMI feed but just ignores the video stream or is it the same as HDMI ARC?

 

[voodooless]

Thanks for the explanation! So if that is what HDMI ARC is.... what is the "HDMI I2S port" on the SMSL PO100 for?
Does HDMI I2S accept a normal HDMI feed but just ignores the video stream or is it the same as HDMI ARC?

This is why these I2S HDMI ports should be banned. They are only confusing!

It’s an I2S interface using HDMI cabling, nothing more nothing less. It has nothing at all to do with actual HDMI.

 

[staticV3]

what is the "HDMI I2S port" on the SMSL PO100 for?

It's for connecting to certain desktop DACs that have a corresponding HDMI I2S input. It's completely unrelated to HDMI or ARC.

 

[jv99]

Right so the PO100 has USB input and then I2S output to a DAC... ok but why? If the DAC will accept I2S thru HDMI then it will also surely have a USB input too?! So how does going USB->I2S->DAC make any more sense or improvement than just connect USB->DAC directly?!

 

[jkim]

"Best to use the digital outs on your HDMI extractor (or replace it if poor) run that to a DAC that has digital volume control and a remote."

Sorry if I misunderstood the the last part... staticV3 says I will be able to adjust volume using my phone just as I currently do and introduction of an optical cable won't affect this. This is important because SU-1 does not have a separate remote control for volume. Is this what you mean? Or do you disagree with staticV3?

If you were able to control volume on your Roku streaming device through your current DAC's HDMI connection, you should still be able to do the same thing with optical output conversion. The only explanation of being able to control volume is that the Roku device transmits digitally attenuated signal through HDMI. There's no reason optical out conversion will change it.

By the way, why the SU-1 instead of the newer PS200?

 

[staticV3]

Right so the PO100 has USB input and then I2S output to a DAC... ok but why? If the DAC will accept I2S thru HDMI then it will also surely have a USB input too?! So how does going USB->I2S->DAC make any more sense or improvement than just connect USB->DAC directly?!

I believe some specialty DACs have no internal USB bridge and so that's where the PO100Pro comes in.

Though in practice, it's usually customers whose DACs already have an internal USB bridge but they believe that using an external bridge into the DAC's I2S input improves sound quality somehow.

This is of course just cognitive bias.
The mindset is More effort + more expenses + discrete everything = better sound quality.

 

[jv99]

By the way, why the SU-1 instead of the newer PS200?

Good question! The only reason is because my old previous Roku (NowTV) box with analog output that sounded sort of acceptable also has an AKM brand DAC. You can see it here in this teardown video at 5:00 mins... it looks like an AKM 4430ET chip.

1.)

2.) https://download.mikroe.com/documents/datasheets/AK4430_datasheet.pdf

So it the PS200 is the better option then? Btw I did look at the super cheap PS100 but reviews seems to indicate it's much inferior.

3.) https://www.audiosciencereview.com/...ps100-30-00-dac-some-limitations-apply.47033/

What confuses me most is that I would have thought even the basic PS100 as a standalone £30 DAC should be an upgrade over the cheap Roku box from 10 years ago? Is this perhaps not the case because comparing link 2.) with 3.) suggests the PS100 has worse specs than the AKM 4430 dac chip? (85db vs 91db THD+N and 96db vs 104db dynamic range.)

 

[jkim]

Good question! The only reason is because my old previous Roku (NowTV) box with analog output that sounded sort of acceptable also has an AKM brand DAC. You can see it here in this teardown video at 5:00 mins... it looks like an AKM 4430ET chip.

1.)

2.) https://download.mikroe.com/documents/datasheets/AK4430_datasheet.pdf

So it the PS200 is the better option then? Btw I did look at the super cheap PS100 but reviews seems to indicate it's much inferior.

3.) https://www.audiosciencereview.com/...ps100-30-00-dac-some-limitations-apply.47033/

What confuses me most is that I would have thought even the basic PS100 as a standalone £30 DAC should be an upgrade over the cheap Roku box from 10 years ago? Is this perhaps not the case because comparing link 2.) with 3.) suggests the PS100 has worse specs than the AKM 4430 dac chip? (85db vs 91db THD+N and 96db vs 104db dynamic range.)

A DAC device's performance is not determined by its adopted DAC chip alone. That is why you need to make a judgment based on measurements of each complete product. With respect to measurements, both the SU-1 and PS200 are transparent beyond audibility, although the PS200 exhibits measurably higher performance. One obvious benefit of the PS200 is its Bluetooth support.

 

[jv99]

Well, it looks like Amazon on out of stock for PS200. I've seen it from eBay sellers but I don't trust them for future faults/warranty claims. I can't find stock anywhere else, so maybe SU-1 is only option. Where did you buy from?

BTW the bluetooth on PS200 SBC codec, not LDAC or even AptX.. Is there any similar ~£70 model which has proper LDAC or AptX+ support so bluetooth can also be viable?

Many thanks

 

[jkim]

If you want a DAC with both optical and Bluetooth (w/ LDAC support) inputs on a budget, the FiiO BR13 may be worth considering. It even supports 10-band PEQ. What a combination.

Sure, the BR13 has not been measured by a third-party reviewer. But their published parameters are usually accurate. In fact, I generally have no problem with hardware implementations done by similar Chinese brands (i.e., FiiO, SMSL, Topping, etc.) unless they are too ambitious in designing something unique (beyond off-the-shelf designs suggested by chip manufacturers). Their weakness is software engineering. Hardware is fine. It seems that some users (here and here) are satisfied. I am even tempted to test it when I get a chance...

 

[jv99]

If you want a DAC with both optical and Bluetooth (w/ LDAC support) inputs on a budget, the FiiO BR13 may be worth considering. It even supports 10-band PEQ. What a combination.

Sure, the BR13 has not been measured by a third-party reviewer. But their published parameters are usually accurate. In fact, I generally have no problem with hardware implementations done by similar Chinese brands (i.e., FiiO, SMSL, Topping, etc.) unless they are too ambitious in designing something unique (beyond off-the-shelf designs suggested by chip manufacturers). Their weakness is software engineering. Hardware is fine. It seems that some users (here and here) are satisfied. I am even tempted to test it when I get a chance...

Thanks for your suggestion. I'll order the BR13 now; it says the 10-band eq doesn't work for optical/coax so maybe it's more of a gimmick... still it's something to experiment with via BT connection!

I'll post back if I'm happy with it but really my words mean nothing as anything has to sound better than what I'm using. Hopefully it'll get measured on here soon to see how badly they had to cut corners

 

[jv99]

FWIW: On optical it seems to work well, sound has a little more impact, especially the bass which is tighter with more depth. The higher freqs are more detailed too. It does feel like a flat, neutral sound tho... and lacks warmth to my ears. Overall I'm happy with the sound improvement, so it was a good buy for me. However it does have a few drawbacks as follows:

On startup then EQ always defaults to Jazz setting...! All the EQ presets are TERRIBLE, they make the sound muddy and dull. The EQ adjustment is only available by the phone app AND the won't anyway via Optical/Coax input!

So I thought I'd test the Bluetooth LDAC lossless option... big mistake! I enabled LDAC on phone and it confirmed on the device screen but the sound is still noticeably not quite as good, worse still the occasional pops and distortion creep in. Also the BT digital vol control from your phone is not smooth or granular, i.e..it's sounds very quiet until you swipe into the last 85%-100% of the vol slider and it then gets super loud very quickly so it's awful for volume adjustment. Over optical the volume control works perfect. Because of this I didn't even bother testing the EQ app... especially as it demanded Location setting turning on to connect with the DAC device!!

So in conclusion I think LDAC is overrated at least on this device. You're probably better getting an SU-1 or PS200 as the sound is likely even nicer and forgo the "bonus" features on the BR13 which are mostly unusable or poorly implemented! Still I just use the optical and for that it's at least a noticeable improvement so I'll keep it!

 

[jkim]

Thanks for reporting back to us.

If the BR13 sounds alright with USB or SPDIF inputs (i.e., as a pure DAC), then it is unlikely that you'll hear improvement from a higher priced DAC. In my experience, beyond a certain quality point, it is not likely to distinguish one DAC from another in level-matched blind tests...