Audiowise Opto-USB, SRC-DX and early experiments with the Chord Qutest before moving to TT2

[Fourlegs]

2 minutes ago, Gavin1977 said:

I actually didn’t have time with the qutest, just the TT2 and the DAVE.  However based on my prior experiments with the qutest I can tell you with a large degree of certainty that it’s going to have the same effect.

Gavin, I use the src-dx with my Qutest and I would describe the improvement as ‘significant’. This is with normal redbook files and also with PGGB files on my Innuos Zen Mini. The rest of that system really very ordinary with an old MF X-A2 amplifier and old Dali 104 speakers and yet the difference is easily heard. 

[Fourlegs]

57 minutes ago, edwardsean said:

This move to the SRC-DX has really been interesting. I used to use it with my DAVE (+SeanJacobs PS), but then I got an Innous Phoenix and switched to USB. I’ve really been pleased with the Phoenix. 

 

Sine the Phoenix is designed for USB, I never thought to try and go from server to Phoenix to SRC-DX to DAVE BNC. Does that make sense to even attempt? 

I use PhoenixUSB to SRC-DX to my Dave and have also tried it with my Qutest. This was using USB from both my Antipodes K50 and from my Innuos Zenith. Using the PhoenixUSB in circuit seems to help with sound quality even when using the SRC-DX but it is by no means essential to get the SRC-DX magic.

 

The reason for using the SRC-DX with the Chord DACs is to avoid using their Amanero USB controller chip which is stated by some to have a high latency. This all kicked off with Taiko stating that the USB input on the Dave was not one of their supported DACs for use with the Extreme. Then a few of the Extreme owners started using the SRC-DX so they could take usb from the Extreme and convert it to BNC to connect to the lower latency BNC input on the Dave. That produced startling results for the Extreme owners in terms of sound quality uplift and therefore those of us who do not have Extremes wondered if this was just an Taiko Extreme thing or whether it could work for other USB output streamers as well.

 

Well it turns out that it sure does work for other sources as well as the Extreme and I have been startled by the uplift in sound quality  by converting the USB output from my Innuos and Antipodes streamers to BNC and using that to input to my Dave and my Qutest.

 

Of course the Antipodes K50 can output single BNC as one of its selectable digital outputs and many K50 owners had already decided they preferred the K50 BNC output compared to USB when connected to the Dave.

 

However that single USB from the K50 cannot handle 705 or 768kHz files from say PGGB or HQ Player and that is where the SRC-DX comes into play because it can take a USB signal at those rates and convert it to dual BNC suitable for Dave, TT2, Qutest etc.

 

So yes, @edwardsean, I suggest you should certainly try the SRC-DX with your Phoenix.

[Fourlegs]

12 hours ago, Fourlegs said:

However that single USB from the K50 cannot handle 705 or 768kHz files from say PGGB or HQ Player and that is where the SRC-DX comes into play because it can take a USB signal at those rates and convert it to dual BNC suitable for Dave, TT2, Qutest etc.

my bad, I of course meant to say, “However that single BNC from the K50 cannot handle 705 or 768kHz files from say PGGB or HQ Player “

[Fourlegs]

4 minutes ago, BlueDL said:

I am surprised that the ifi DC iPurifier made a difference given what was already in the chain.

 

I know what you mean about being careful with the spends. Getting a Farad Super3 to power my M-Scaler was somewhat extravagant by my standards.

 

Not sure what the score is with the Paul Hynes business? The Sean Jacobs DC3 was the go-to ‘affordable’ boutique power supply until it was discontinued recently. I personally think that was an own goal, because it struck me as the performance-value sweet spot. [I cringe at using a football analogy after last night’s farce 🤦🏻‍♂️]

 

Having just sold my Sean Jacobs DC3 I can say they do come up second hand every now and then (just not very often!).

 

I see you have the Farad Super3 and I also very much like but am just about to put my 15V Farad Super3 on the Bay (suitable for Mscaler or TT2 etc) because I robbed a bank and have a DC4 to replace it. (Only joking about the bank bit if the fuzz read this forum! 🤪)

[Fourlegs]

10 hours ago, creativepart said:

There is a STD and HIGH output switch - the instructions say to keep it at on HIGH (out) for Chord products.

 

My SRC-DX is used with various Chord products such as Qutest, Dave, Mscaler etc and I always use it on the STD output with all of them. I am not quite sure why AudioWise think that the HIGH setting might be better for Chord devices but my logic is to use the lowest output voltage that reliably works in case the high setting also increases any noise overlaid on the digital signal.

 

Anyway I hope you get the volume thing sorted. Dan is indeed helpful with such things.

[Fourlegs]

4 hours ago, Atriya said:

I did not initially notice an improvement with the SRC-DX. At the time it was connected directly to my laptop. It was only when I replaced the laptop with a RPi powered by the Shanti that there was a very significant improvement. So, it's hard to say if the improvement was because of the RPi+Shanti itself, or because the RPi+Shanti just unlocked the performance of the SRC-DX.

That is interesting The SRC.DX is powered by the 5V usb rail from the source. So in your first setup with the laptop you were powering the SRC.DX with the 5V from the laptop.

 

I have an Innuos PhoenixUSB in line before the SRC.DX and so the SRC.DX is getting exceptionally clean power from the Sean Jacobs power supply within the PhoenixNET. I suspect that is helping me with the huge difference I hear by having the SRC.DX in my system connecting to the BNC input on my Mscaler. Also, the bnc cable from the SRC.DX does play a part in the sound quality and it will come as no surprise that I use my own WAVE Storm cable there.

[Fourlegs]

@Atriya I use an Innuos PhoenixUSB reclocker before my SRC.DX usb to bnc converter. I think the sound is still improved by using the Phoenix but to be honest I’m not sure how much of that is down to the quality of the 5V usb power rail outputted by the Sean Jacobs power supply in the Phoenix and  which of course is powering the SRC.DX. 
 

Whatever the reason I keep the Phoenix reclocker in my system. Whether this is the same for all other usb reclockers I do not know. 

[Fourlegs]

@LowOrbit Just on the Phoenix power, its regulator stage is DC4 but the rectifier / cap board is based on the DC3 so whilst the 5V from the Phoenix is indeed good, it is not probably 'as good as you can get'. I know this having gone through the upgrade stages with my Dave / Mscaler from DC3 to DC4 to ARC6 and where the only change with ARC6 is the rectifier / cap board and yet it makes a big difference. Just for fun I might therefore try powering the SRC.DX from a 5V ARC6 and I expect that might take the sound to a different level.

[Fourlegs]

30 minutes ago, Atriya said:

 

So, when using the SRC-DX, there is no benefit to upgrading upstream components such as the streamer/source, except that it might provide cleaner power? I use a Raspberry Pi 4 as source but am injecting 5V from a linear PS (Allo Shanti) just before the SRC-DX. So, upgrading the Pi to something like a SoTm SMS-200 Ultra which has a higher-quality clock should have no impact, and I should instead focus on upgrading the Shanti?

 

I'm not sure what you mean by "It clocks the output, doesn't need to "reclock". Since the USB input is clocked by the streamer, doesn't any further clocking by definition constitute a RE-clocking? And if the signal isn't clocked by the streamer, then why do streamers like the SoTm I mentioned above, advertise their high quality clocks?

 

I don't think you can say that upstream devices before the SRC.DX will not make a difference.

 

Even with a PhoenixUSB in the system I easily hear differences between say :-

1) Innuos Zenith / PhoenixUSB / SRC.DX  or 

2) Antipodes K50 / PhoenixUSB / SRC.DX

 

Of course the other thing that also makes an easily heard difference is which BNC cable(s) one uses from the SRC.DX to the DAC.

[Fourlegs]

On 10/2/2022 at 10:52 PM, Atriya said:

 

So, noise in a source (e.g. laptop, RPi4) can degrade the digital signal itself in some way other than jitter? (Given that jitter can't be the factor, since I'm using a Chord DAC.)

 

What kind of degradation might this be? I thought the signal from any source, including a laptop, is bit-perfect when using and source files and software (in my case lossless files & HQPlayer WASAPI exclusive mode for laptop and NAA for Rpi4)?

The usual mechanism for noise overlaid on a digital signal to affect sound quality is for it to cause issues in the analogue stage of the DAC. The resulting IMD is easily heard even at low levels. Note that this is not background noise..

The fact that the signal is bit perfect does not protect it from this noise causing issues. The noise is mostly out of audio band noise and sometimes can be as high as RF.

 

Whilst the Opto-USB provides an optical break, the receiving end to convert the signal back to USB requires a 5V power source and I wonder if it is possible that will allow noise to flow in the ground plane and bypass the optical break.