[AussieMick]

Looked at another way, there is no electrical signal that can be absolutely identified as "noise." "Noise" is just a way to describe any electrical signal added to the original signal that the end-user doesn't want (as opposed to "distortion" which is an alteration of the signal).

"Noise" is like the word "weed." There is no actual plant that is identifiable as a "weed." A "weed" is just a catchall term for any plant you don't want in your garden. Just like your garden doesn't care about the difference between a "vegetable" and a "weed," electronics don't care about the difference between "signal" and "noise." They just do their job, which is to conduct electrical currents. Designers do their darnedest to keep signal and noise separate, but electronic components could give a giant F. They just want to conduct.

Which is why it’s so important to keep weeding, right? Getting the noise floor ever lower reveals more and more low level detail. It becomes extremely important to some listeners, which is why they invest power distribution and regeneration, cables with good grounding, grounding boxes and the like, cables with good resistance to mechanical noise, devices to isolate gear from vibration, devices to drain away vibration created within gear, room treatments…and that’s all on the analogue side. Then there are people who invest heavily in the digital dude with USB reclockers, Ethernet switches, optical isolators, digital cables with better noise rejection…the list goes on.

One of the problems we have in discussing all of this is where people live. If you live on the seventh floor of an old walk-up in Hoboken, surrounded by a hundred people all using blenders and refrigerators and vacuum cleaners and microwaves and multiple wifi and Bluetooth devices, these things will matter more to you than if you live in a rural area without as much interference (although it’s still there in lesser amounts). So one person trying a given device might find it very influential, while another hears nothing, then the two jump on a forum to compare experiences and it tends to go downhill from there.

It tends to make my personal experiences and your personal experiences incredibly relevant to ourselves, but not so much to people with different circumstances. It’s why I like to listen to those who are bringing product to market and what those designers (not marketing departments) have to say about “electrical noise” as it pertains to “hifi systems”, as we don’t listen to any one element on its own.



I agree with you 100% about your weed analogy. I’d like to use that, if you don’t mind.

 

[Jerome Howard]

I collect antiques radios from the 1930's. I can tell you that just about every appliance, phone charger, modem, cable box, TV, Alexa, etc. in my home adds interference.

When everything is being used, I can barely hear stations from more than about 40 miles away, and with static. Unplug everything, and the distance doubles or triples, and is very quiet. As I unplug things one by one, the signal gets a little better with each thing I unplug.

Electrical noise is everywhere.

 

[chelseafc]

@Rob Watts - I would like to report a couple of issues with Mojo2.

I got interested in it following a post on Audiowise’s blog claiming that Mojo2 could rival DAVE when coupled with M Scaler.
It sounded too good to be true, but I decided to give it a try anyway.
My current setup is M Scaler -> OPTO-DX -> DAVE -> Luxman 595SE -> Sonus Faber Olympica Nova III.
The very first thing I discovered when replaced the DAVE with Mojo2 is an intolerable hum emanating from the speakers, but only when Mojo2 connected to the amp through the output farthest from the LEDs.
I get that hum even without firmly connecting DBNC inputs, just by holding Mojo2 in one hand and touching any cable that has connection to the GND.
The other output port is dead quiet.

Secondly, I believe there is a bug in the DBNC implementation (at rates > 384Khz).
When the BNC inputs connected correctly (I established BNC1 position on the RCA adapter at lower rates), the 705/768 tracks sound pretty bad, out of phase.
The magic happens when I reverse the inputs.
I have to say, with swapped BNC inputs, at 705/768 rates Mojo2 sounds as good or very close to DAVE to my ears.
BTW, I have another person who confirmed my findings after I shared them with him.

 

[flyte3333]

Anyone using Truthear Nova or Red IEMs?

Any hiss with Mojo2?

 

[alxw0w]

There’s more to it than that. I’m talking about noise that travels independently of the data. Noise in mixed signal systems. Noise travelling on the ground plane, noise created by transceiver chips, conducted and radiated noise. It’s everywhere.

Damn noise, it's everywhere

 

[Digital Enigma]

@Rob Watts - I would like to report a couple of issues with Mojo2.

I got interested in it following a post on Audiowise’s blog claiming that Mojo2 could rival DAVE when coupled with M Scaler.
It sounded too good to be true, but I decided to give it a try anyway.
My current setup is M Scaler -> OPTO-DX -> DAVE -> Luxman 595SE -> Sonus Faber Olympica Nova III.
The very first thing I discovered when replaced the DAVE with Mojo2 is an intolerable hum emanating from the speakers, but only when Mojo2 connected to the amp through the output farthest from the LEDs.
I get that hum even without firmly connecting DBNC inputs, just by holding Mojo2 in one hand and touching any cable that has connection to the GND.
The other output port is dead quiet.

Secondly, I believe there is a bug in the DBNC implementation (at rates > 384Khz).
When the BNC inputs connected correctly (I established BNC1 position on the RCA adapter at lower rates), the 705/768 tracks sound pretty bad, out of phase.
The magic happens when I reverse the inputs.
I have to say, with swapped BNC inputs, at 705/768 rates Mojo2 sounds as good or very close to DAVE to my ears.
BTW, I have another person who confirmed my findings after I shared them with him.

I wouldn't be surprised if you found them close, a lot of people now prefer Mojo2 over Qutest for its faster transients and speed. I hear Rob has got a lot on at the moment so I wouldn't expect any lower priced dacs soon but I think when the time comes the "Qutest 2" will be the sweet spot for many.

 

[gc335]

I'm thinking about picking up a Hiby R3 II to stack with my Mojo 2. I'm hoping to get some feedback on how they work together and how you connect them. USB or Coax and a good cable that works.

 

[rlw6534]

I'm thinking about picking up a Hiby R3 II to stack with my Mojo 2. I'm hoping to get some feedback on how they work together and how you connect them. USB or Coax and a good cable that works.

I have an R3 Pro 2022 that I use with my Mojo at times. I have the Hiby Coax cable but USB has worked just fine (FiiO and Lotoo short cables). The coax cable is a bit more secure IMO. The good thing about the R3 Pro is that you can actually buy a 3D printed case for use with the Mojo 2. I haven't seen one for the R3 II yet.

https://store.hiby.com/products/hiby-type-c-to-3-5mm-gold-plating-coaxial-cable

https://www.ebay.com/itm/3348659040...uid=nsInQwZqTFK&widget_ver=artemis&media=COPY

 

[gc335]

I have an R3 Pro 2022 that I use with my Mojo at times. I have the Hiby Coax cable but USB has worked just fine (FiiO and Lotoo short cables). The coax cable is a bit more secure IMO. The good thing about the R3 Pro is that you can actually buy a 3D printed case for use with the Mojo 2. I haven't seen one for the R3 II yet.

https://store.hiby.com/products/hiby-type-c-to-3-5mm-gold-plating-coaxial-cable

https://www.ebay.com/itm/3348659040...uid=nsInQwZqTFK&widget_ver=artemis&media=COPY

Super helpful! Thanks.

 

[DavidWeinberg]

While listening today to:

The music went silent while still playing (as displayed on my phone) and the menu light was flashing. I power cycled the Mojo2/Poly and resumed playing.

All appears to be okay. What could be the cause? Anything I need to be alerted to?

 

[miketlse]

While listening today to:

The music went silent while still playing (as displayed on my phone) and the menu light was flashing. I power cycled the Mojo2/Poly and resumed playing.

All appears to be okay. What could be the cause? Anything I need to be alerted to?

I recall occasional posts about music going quiet, whilst it is still playing, but I can't remember which thread it was on.
Hopefully someone will post about it, because I am struggling to think of a good search term to locate those posts.

 

[paulrbarnard]

While listening today to:

The music went silent while still playing (as displayed on my phone) and the menu light was flashing. I power cycled the Mojo2/Poly and resumed playing.

All appears to be okay. What could be the cause? Anything I need to be alerted to?

I had this happen to me once and I reset as you did. It happened a second time and I realise then that the volume indicators were all off. I was carrying the Mojo at the time and probably manage to hold the volume down button in.

 

[huangwan]

I had a thought, since Chord does not do firmware updates for their DACs, for security reasons. Would it be possible to update the DAC via Poly?

 

[Hypops]

I had a thought, since Chord does not do firmware updates for their DACs, for security reasons. Would it be possible to update the DAC via Poly?

…but there’s nothing to update it to.

 

[rmkjr]

I had a thought, since Chord does not do firmware updates for their DACs, for security reasons. Would it be possible to update the DAC via Poly?

I take it his concern is the HDL being available digitally in any form outside of Chord internally or what’s flashed to physical hardware.

I would be nice though for edge cases found after the fact like the USB issues. Perhaps encrypting it and making the Poly itself decrypt it. But I’m guessing it’s likely that the FPGA’s programming interface isn’t even reachable from the Mojo’s USB port