[Tjj226 Angel]

The one thing I still don't quite understand is pulse array. I get that you have a number of elements that have all been slightly time shifted such that 2 elements will cancel for any given edge of data, but I don't quite understand how this works.

In my mind, this means you have 10 slightly time shifted signals all arriving at some output. How can these signals sum up to 1 signal if they are all slightly different?

And if the goal is to have a rising edge canceled by a falling edge, wouldn't it make more sense to just have a balanced/differential signal that isn't time shifted? I get that you get some benefit in having multiple elements because it lowers the impedance, but why not run a bunch of differential signals in parallel?

I feel like I am missing something obvious.

 

[ecwl]

The one thing I still don't quite understand is pulse array. I get that you have a number of elements that have all been slightly time shifted such that 2 elements will cancel for any given edge of data, but I don't quite understand how this works.

In my mind, this means you have 10 slightly time shifted signals all arriving at some output. How can these signals sum up to 1 signal if they are all slightly different?

And if the goal is to have a rising edge canceled by a falling edge, wouldn't it make more sense to just have a balanced/differential signal that isn't time shifted? I get that you get some benefit in having multiple elements because it lowers the impedance, but why not run a bunch of differential signals in parallel?

I feel like I am missing something obvious.

In this video, about 3.5 minutes in, you can sort of see how pulse array works.

The goal is not just to have a bunch of rising edge cancels falling edges but to limit it to only 1 edge cancelling each other all the time (except when the signal changes slightly by 1 edge). Because if you have 8 edges cancelling each other at the same time sometimes and 1 edge cancelling at other times, you’re going to have massive fluctuations causing noise floor modulation and increasing jitter. Moreover, when that happens, often it’ll become signal dependent which causes other sonic artifacts. At least that’s my layman’s understanding.

 

[audionewbi]

I hope I can see Hugo 3 this year. I still love my Hugo, skipped Hugo 2 but after trying all the DAP in the market ( and I do mean all the main stream), I've went back to mu Hugo using optical in, and it just works.

 

[Tjj226 Angel]

In this video, about 3.5 minutes in, you can sort of see how pulse array works.

The goal is not just to have a bunch of rising edge cancels falling edges but to limit it to only 1 edge cancelling each other all the time (except when the signal changes slightly by 1 edge). Because if you have 8 edges cancelling each other at the same time sometimes and 1 edge cancelling at other times, you’re going to have massive fluctuations causing noise floor modulation and increasing jitter. Moreover, when that happens, often it’ll become signal dependent which causes other sonic artifacts. At least that’s my layman’s understanding.

Thank you for the response. I have watched that video serval times.

I get that one edge is always canceled by just 1 other edge. I even understand how choosing the number of elements is related to the resolution of the PWM signal.

Where I lose the plot is when we look at each element individually.

Each element is essentially a single PWM signal of the whole music signal. In other words, If we could just play a single element out of the array and we would have music on the output. This is how you get matching across all the elements in the array.

But since each element is slightly delayed, each signal will arrive at the output at different times. How is it possible that 10 or 20 slightly different signals all sum up to 1 "correct" signal.

A different way of saying it is how does this function make sense?

((Signal1 + 0t) || (Signal2 + 1t) || (Signal3 + 2t) || (Signal4 + 3t) || (Signal5 + 4t) || (Signal6 + 5t) || (Signal7 + 6t) || (Signal8 + 7t) || (Signal9 + 8t) || (Signal10 + 9t)) = Signal1 + 0t

Where t is not equal to 0.

And again, why go through the trouble of time shifting everything? Wouldn't a differential signal cancel just once at every rising and falling edge without the need for time shifting? I'm not trying to be intentionally dense, but this has been bugging me for years. I saw Mr. Watts presentation a while back at cam jam and I have regretted not asking these questions.

 

[miketlse]

I hope I can see Hugo 3 this year. I still love my Hugo, skipped Hugo 2 but after trying all the DAP in the market ( and I do mean all the main stream), I've went back to mu Hugo using optical in, and it just works.

'Not for some considerable time'.
https://www.head-fi.org/threads/chord-electronics-hugo-2-the-official-thread.831345/post-17882753

 

[ecwl]

Thank you for the response. I have watched that video serval times.

I get that one edge is always canceled by just 1 other edge. I even understand how choosing the number of elements is related to the resolution of the PWM signal.

Where I lose the plot is when we look at each element individually.

Each element is essentially a single PWM signal of the whole music signal. In other words, If we could just play a single element out of the array and we would have music on the output. This is how you get matching across all the elements in the array.

But since each element is slightly delayed, each signal will arrive at the output at different times. How is it possible that 10 or 20 slightly different signals all sum up to 1 "correct" signal.

A different way of saying it is how does this function make sense?

((Signal1 + 0t) || (Signal2 + 1t) || (Signal3 + 2t) || (Signal4 + 3t) || (Signal5 + 4t) || (Signal6 + 5t) || (Signal7 + 6t) || (Signal8 + 7t) || (Signal9 + 8t) || (Signal10 + 9t)) = Signal1 + 0t

Where t is not equal to 0.

And again, why go through the trouble of time shifting everything? Wouldn't a differential signal cancel just once at every rising and falling edge without the need for time shifting? I'm not trying to be intentionally dense, but this has been bugging me for years. I saw Mr. Watts presentation a while back at cam jam and I have regretted not asking these questions.

The elements are not mathematical objects but physical switches so it’s impossible for the elements to be identical. That means signal1 is not perfectly equal to signal 2 and 3 and 4 and 5. Most DACs use some form of dynamic element matching so that if you just a signal level of 1 (out of 10) instead of always firing signal 1, you would sometimes fire signal 2 or 3 or 4 or 5. That way it evens out the errors amongst the elements.

As to why a differential signal approach is not equivalent to a constant switching approach, you can think of it this way.

Let’s imagine a signal of 000111
So in differential signal, you’ll actually have 000111 on one end and 000-1-1-1 on the other end which is basically still 000111

In a constant switching scheme, to get 000111
Flip up 111111
Flip down 111011

But in a differential scheme
Flip up 000100
Flip down 000000 for the positive end
Flip up 000000
Flip down 000100 for the negative end
So what you’re saying is that it’s the same thing because the differential scheme canceled each other.
Except when the elements are not flipping, they have a different energy level and less noise than when the elements are flipping. And flipping up and down also tend to have slightly different levels of energy. These slight differences would generate varying degrees of noise.

so far, we are dealing with a small signal change. If we are going from super quiet to super loud in a differential scheme then suddenly you’re going to have signal dependent noise because you only need to switch when the music is loud and you don’t switch much when the music is soft.

This is why constant switching schemes tend to have lower levels of jitter and noise floor modulation.

Like I said, I’m thinking about this like a layman so my explanations are very clumsy. But I hope this makes sense.

 

[Tjj226 Angel]

The elements are not mathematical objects but physical switches so it’s impossible for the elements to be identical. That means signal1 is not perfectly equal to signal 2 and 3 and 4 and 5. Most DACs use some form of dynamic element matching so that if you just a signal level of 1 (out of 10) instead of always firing signal 1, you would sometimes fire signal 2 or 3 or 4 or 5. That way it evens out the errors amongst the elements.

As to why a differential signal approach is not equivalent to a constant switching approach, you can think of it this way.

Let’s imagine a signal of 000111
So in differential signal, you’ll actually have 000111 on one end and 000-1-1-1 on the other end which is basically still 000111

In a constant switching scheme, to get 000111
Flip up 111111
Flip down 111011

But in a differential scheme
Flip up 000100
Flip down 000000 for the positive end
Flip up 000000
Flip down 000100 for the negative end
So what you’re saying is that it’s the same thing because the differential scheme canceled each other.
Except when the elements are not flipping, they have a different energy level and less noise than when the elements are flipping. And flipping up and down also tend to have slightly different levels of energy. These slight differences would generate varying degrees of noise.

so far, we are dealing with a small signal change. If we are going from super quiet to super loud in a differential scheme then suddenly you’re going to have signal dependent noise because you only need to switch when the music is loud and you don’t switch much when the music is soft.

This is why constant switching schemes tend to have lower levels of jitter and noise floor modulation.

Like I said, I’m thinking about this like a layman so my explanations are very clumsy. But I hope this makes sense.

Yeup. Im stupid. When you put it in terms of the data stream it makes perfect sense why differential is not a thing. I should have known that too.

The first part though is something new. I'm not familiar with dynamic element matching. This might be where Im getting lost and how 10 elements equals somehow equals 1 output.

 

[Nuno Silva]

Dear Mr. @Rob Watts, following @stemiki and @miketlse advise on how to best address the absence of a optical connection on my Stack Audio Link II streamer, I bought a Topping D10S to use as a digital connection between the streamer and the M Scaler using the BixPower batteries pack. The USB Out on the streamer is connected to USB In on the Topping and then from the Topping Optical Out to the M Scaler Optical In. The problem is that sometimes there's a "hiccup" at the beginning of a song, especially if the sampling rate changes. Also, I have noticed that while playing Gina Alice's Wonderworld from Qobuz (24Bit/192kHz) there is no sound at all, just complete silence and there's no light (of any colour) in the DX OP, but if I play the Tidal's MQA version, it plays as usual. I should mention that the Topping's display while playing the Qobuz version shows, as it should, 192kHz PCM and the Tidal version 48kHz. Any idea what must be wrong? Many thanks in advance.

 

[Digital Enigma]

'Not for some considerable time'.
https://www.head-fi.org/threads/chord-electronics-hugo-2-the-official-thread.831345/post-17882753

Yeah chord don’t release a DAC every 4 months like topping and smsl. It’s always going to be a long wait from a reputable manufacturer. When you take your time and do something well it won’t need a successor for years.

 

[gnomen]

Before we all get too carried away, it might be worth watching this cautionary tale about a hi-fi fanatic: https://slippedisc.com/2024/01/the-man-with-the-1m-hi-fi-a-cautionary-tale/

 

[Digital Enigma]

Shame he passed away not long after finally achieving his goal.

 

[Jawed]

Spoiler: Deleted video

Since that video was deleted, the replacement is:



This is "editorialised" and I think some of what Rob said has been lost when compared with the original, but I'm not sure.

Quartet Scaler:

• 5 FPGAs of the same type as in the Hugo M Scaler
• 4 million taps
• separate power supply
• high power consumption
• improved filtering for BNC outputs

 

[Reactcore]

Quartet Scaler:

• 5 FPGAs of the same type as in the Hugo M Scaler
• 4 million taps
• separate power supply
• high power consumption
• improved filtering for BNC outputs

And said will be launced at Munich in may
Thanks for sharing J.

Lol and Ultima DAC next year following John

 

[zen87192]

£9,995.00 GBP perhaps…

 

[ecwl]

£9,995.00 GBP perhaps…

My main concern is the two boxes. Thinking of the cheapest Choral product, it’ll be that x2 minimum. Will have to wait to see the pricing. I think your pricing is the minimum price.