HiBy R4

[Hypops]

Does anyone understand this bias stuff enough to know if the bias can be ajdusted via software or is that something done through hardware?

My guesses above were just that: guesses. So we shouldn’t assume that that’s actually what’s going on. But it sounds like a lot of owners of the OG R4 didn’t realize just how hot a Class A design can get, so Hiby adjusted it to run cooler and with less power draw.

I wonder how much the sound change was a "discovered" affect of reducing the heat from the Class A amp, because heat is part of what makes a Class A amp sound like a Class A amp. I'm wondering if the reducing heat came first, with a result in increased battery life and sound change.

It’s all interrelated. Class A is horribly inefficient (chews through power and generates lots of heat), but it gets its characteristic sound as a direct result of its inefficiency (constant power draw and constant temp).

 

[CJ_CoCa]

I haven't pulled the trigger yet on the Eva r4. I think I'll just wait for reviews and impressions once it gets to people's hands and hope that it is still available if (when?) I decide to get it.

This would be my first dap but at the same time I'm in no rush to get one, so I'll just wait and see. I hope those of you who get it love it and I get to join you in the not so distant future!

 

[anli]

My guesses above were just that: guesses. So we shouldn’t assume that that’s actually what’s going on. But it sounds like a lot of owners of the OG R4 didn’t realize just how hot a Class A design can get, so Hiby adjusted it to run cooler and with less power draw.


It’s all interrelated. Class A is horribly inefficient (chews through power and generates lots of heat), but it gets its characteristic sound as a direct result of its inefficiency (constant power draw and constant temp).

It's a bit more... variable. When we say "class A", we must add "for load with impedance X". So, say, if an amp is working in class A for 50 Ohm load, it moves to class AB on, say, 25 Ohm load. And it is still "warm AB" not too efficient as "economical class AB". At any case everything is defined by so called "quiescent current" (a current through output transistors on signal absence). The more - the better for sound (within certain limits).
Current original DAP version's quiescent current isn't too large to make a DAP really hot (the DAP is just warm in a pocket at my case). Time of operation is also absolutely acceptable.

 

[Richsvt]

If I hadn't gotten my R4 a couple months ago and saw the purple, I might have been tempted. As it stands right now, I use my R4 as my out and about player. I do not need another. While the small increases are intriguing, it cannot justify the costs over what I paid for the OG R4. Let's see how this form evolves over the next year or so and then maybe it may enter into consideration. I'm still digging the R4 I have and see no need to augment it.

 

[Joe Bloggs]

There's buttons overlaid on the words "Bluetooth Receiving Mode" in an unclear way. There's an X button on the left to exit the mode, and another button on the right to enter and edit systemwide audio settings options.

By the way, there is built in facility to change the text and display sizes in Display. (I would suggest smaller, if your eyes are up for it).

 

[anli]

if your eyes are up for it

Unfortunately they are not.

 

[Joe Bloggs]

I wonder if Hiby simply lowered the bias of the Class A circuit? Means it would sound less "beefy" and Class A-like, but would also produce less heat and use less power (i.e., battery). Would line up with most of their descriptions of the changes to the Eva edition: more energy efficient, less heat, decreased soundstage, and thinner/brighter sounding.

Looks like a fair assumption to make .. Only thing in which case how are they promising a choice to revert to the OG neutral sound (in future).

Spoiler

I should simply note that they did not EQ anything or do anything that would affect the frequency response, nor did they deliberately add distortion or crosstalk or anything like that. I still have no idea how / why they think it sounds different, other than that people found it sounding different in subjective internal testing.

I also do not think they can revert the change in software (if there is anything to revert). So far plans involve using EQ (to simulate / undo a difference that isn't caused by FR changes...)

Please, you may discuss this but don't quote what I said here in your reply...

 

[captblaze]

In Pure Audio Mode output resolution is locked to 48kHz. Anyone else? Happens in both Hiby Music and Qobuz (streaming tab) app

 

[Joe Bloggs]

In Pure Audio Mode output resolution is locked to 48kHz. Anyone else? Happens in both Hiby Music and Qobuz (streaming tab) app

do you have any systemwide plugins enabled that might cause this? Fixed output sample rate, convolution (other sample rate bypass unchecked)

 

[captblaze]

do you have any systemwide plugins enabled that might cause this? Fixed output sample rate, convolution (other sample rate bypass unchecked)

no I did have some plugins in the menu and deleted them and now issued resolved, Thanks

 

[Unterstuffz]

Can Some shine some light on the Pure Audio Mode as i did Not quite get what is does and i did Not find any documentation online.

 

[Joe Bloggs]

Can Some shine some light on the Pure Audio Mode as i did Not quite get what is does and i did Not find any documentation online.

It dedicates the DAP to running HiByMusic the onboard music app. Some others have apparently hacked it into running UAPP or something else in isolation instead by disabling HiByMusic...

 

[anli]

Not sure anybody (except of me) is interested in, but have measured R4 output impedance and got 0.36 Ohm for SE output.

 

[Hypops]

Not sure anybody (except of me) is interested in, but have measured R4 output impedance and got 0.36 Ohm.

Single ended or balanced? I've seen other similar measurements (earlier in this thread) putting it in that same ballpark. Much lower than the official spec (SE: 1 Ω, balanced: 2 Ω ).

 

[anli]

Single ended or balanced? I've seen other similar measurements (earlier in this thread) putting it in that same ballpark. Much lower than the official spec (SE: 1 Ω, balanced: 2 Ω ).

Sorry, haven't clarified at first it is for SE.