AKM... AKM!!! I hope this isn't what it looks like.... because it looks BAD

[mike7877]

REMEMBER when VW programmed their cars so that when OBD2 reader was connected for emissions testing, the engine ran cleaner but with lower horsepower?

Well I came across this page in the AK4499 Velvet datasheet...

WHAT AM I LOOKING AT?!

I want sound quality mode!

And why would measurement mode, with better measurements, not sound as good as SOUND QUALITY MODE (food for thought in a different way for some people)


SERIOUSLY WTF AKM

 

[jacobacci]

Not everyone prefers their yogurt without sugar

 

[KSTR]

AK4499EQ - Best DAC ever

Depends what you consider better. Typically flat THD+N across audio frequencies is desirable. yep isn't flat without rc please see better the pic you post , with 3300(why not more ?) and r10 is the better profile,living as Markw4 post on sound not so good in this case

www.diyaudio.com

 

[MCH]

I understand from other akm dacs that sound control is used to select the filters or disable them. ie. Ak4495 has 5 settings (4 filters + no filter). But I am not sure.

Another potential clue:

In AKM datasheet language, SC can also mean Sound Color (=filters). I bet the register in question activates or deactivates filters.

 

[mike7877]

I understand from other akm dacs that sound control is used to select the filters or disable them. ie. Ak4495 has 5 settings (4 filters + no filter). But I am not sure

I'd like to believe that, but I have the E70 Velvet with the 4499 Velvet, and it has 6 filters to choose from

 

[Mnyb]

You might not need to bother , look at the data measured from finished products .

There is no built in "audio precison analyser detector" it does not know what signal its' feed . Besides the goal is actually the same ? so who knows where the product designers set this bit in each finished DAC product, does not matter if the product performs .

But no doubt a curios setting that needs some explaining ? but the whole velvet marketing is a bit dubious ?

Never the less products built with this chip seems to perform very well and that's all that counts imo

 

[-Matt-]

There is no built in "audio precison analyser detector" it does not know what signal its' feed .

Surely it would be rather easy to detect continuous test tones and automatically switch modes?

Not saying they do this, but I'd be interested in an explanation of what this feature is intended to do.

 

[staticV3]

Surely it would be rather easy to detect continuous test tones and automatically switch modes?

The DAC chip doesn't have that capability, so you'd have to program it into the USB bridge. Certainly possible, but not really straightforward.

 

[Sokel]

I really miss the days of AKM 4396 which measured decently across every freq,condition and most importantly level.
You never know how they play them these days.

(of course all these stuff are way beyond audibility but still)

 

[mike7877]

So I'm stoopid and made the same thread because I thought this thread was a post in another thread.
I did a better job this time though! Hahaha.
Unfortunately I can't edit the OP, so in it goes as a post!
(I've requested the dupe thread be deleted!)


So I've been perusing the AK4499EX's datasheet (+EX = ver. "Velvet").
Reason being? Curiosity...

And my current favourite DAC for music playback uses it! (Topping E70 Velvet)
(It doesn't matter for this thread, but I also have the L70 (matching HP amp/pre), and I like it lots: it's very nice!


I find this... curious "9.6. - Sound Control"

So there is a pin called "SC pin". I guess you either pull it up or down to switch it from 0 to 1. As you can see L (0) [ie. low/off] puts the DAC in "Measurement Mode", and H (1) [ie. high/on] puts the DAC in..... Sound Quality Mode?!?!?!

OK, hooooollld up, AKM!

Why is the mode for "Measurement" (which, presumably, configures the DAC's internals to measure best), not also best for sound quality?

I can think of one scenario in which Measurement Mode and Sound Quality Mode don't mean what they appear to mean, and that is if this so-called "Measurement Mode" is only for OEM use, during their design phase of the surrounding circuit (it's a protected mode, of sorts, for experimenting with passive parts in the signal path (different values). Maybe it limits maximum current of the outputs or something? So that each mistake isn't -$80. -$80. -$80!!

But!... I don't think that's the scenario. There would be a better name and description for that.

I think... the better sounding mode measures worse!

It's too bad we don't know which mode the DAC was in for the datasheet values. I would assume Measurement Mode (well, they are the measurements...), but wedon't really know, do we?! If Measurement Mode and Sound Quality Mode measure differently (I mean, if they don't, what's it all about?...), the datasheet should contain BOTH! (well, the better one would be measurement mode, but probably not for all parameters, all the time)

Topping is all about being the top of the measurement charts... Does this mean they're shipping their E70 Velvet in the Measurement Mode instead of Sound Quality mode? Personally, I'd rather have my DAC running in Sound Quality mode if it sounds better and measures worse... If it's as simple as cutting the pin at the side of the chip so that the trace isn't pulling it up or to ground, that'd be a GREAT hack... and easy to fix with a bit of solder, too. Since we do have measurements for the E70 Velvet (not here, but on a couple other sites which also measure DACs, often the same ones done here, and the measurements between here and there are quite consistent...), and those measurements match the datasheet pretty much spot on, it makes me thing Topping's put this thing in "Measurement Mode"!

Unless... UNLESS! Unless AKM used "Sound Quality Mode" for the datasheet parameters! That's not the most far-fetched idea...

Even with this.. situation... I'm still very happy with the sound of the E70 Velvet - it sounds GREAT. It's even better than my Arcam rDAC, so I FINALLY have a replacement! (unfortunately the stoopid relay in Mr. rDAC broke. I was so accustomed to his sound! Sounded so good
Always clear, never fatiguing. Plenty of detail, good bass... In Windoze tin I could set it to 24 bit, and use the level in foobar2000 to adjust the volume for the time I didn't have a preamp. It sounded good as ever down to quieter than tv listening levels. Of course there were better DACs out there, but not for the price!


Anywho... Thoughts? Is there a way to find out what mode the E70 V is in? I have an oscilloscope and a reaaaally pointy probe! Know what I should look for to determine if Measurement Mode or Sound Quality Mode is the default? And if the DAC is in the 'wrong' mode, can it be switched? What would switching it look like?

Oh AKM... and Topping. Geez!

 

[voodooless]

It's too bad we don't know which mode the DAC was in for the datasheet values. I would assume Measurement Mode (well, they are the measurements...), but wedon't really know, do we?

We do, it’s stated in the datasheet. All measurements done there are with SC pin low, so measurement mode.

Anywho... Thoughts?

Who cares? Your not going to hear the difference unless this mode severely messes with the audio.

Is there a way to find out what mode the E70 V is in? I have an oscilloscope and a reaaaally pointy probe! Know what I should look for to determine if Measurement Mode or Sound Quality Mode is the default?

Just look at what the pin is connected to: if it’s GND, it’s measurement mode, if VCC, it’s not. If it’s connected to an MCU pin, you’ll have to measure it.

 

[MCH]

It's too bad we don't know which mode the DAC was in for the datasheet values.

Yes we do. It is clearly stated in the capture from the datasheet you posted in post #1

Anywho... Thoughts? Is there a way to find out what mode the E70 V is in?

If the chip is in "register control mode" you would have to tap the i2c pins and read the registers. If in "pin control mode" you could just use a multimeter and measure the voltage at the SC pin. You will need to read the datasheet to see what mode the chip is in. A good guess is checking out if the DAC is connected to a microcontroller or usb bridge or not.

 

[Sangram]

My DAC-A26 has this setting exposed as "Listening" and "Monitoring" on the UI. There is small difference audibly between the two. I would measure it, but don't have a capable enough ADC after my last motherboard with PCI slots died and put my e-Mu 1212m out of action.

 

[mike7877]

We do, it’s stated in the datasheet. All measurements done there are with SC pin low, so measurement mode.
Just look at what the pin is connected to: if it’s GND, it’s measurement mode, if VCC, it’s not. If it’s connected to an MCU pin, you’ll have to measure it.

Cool, I missed it. I will try opening it up tomorrow and see if I can reach that pin from how far I can pull the board out. I think it's pretty hard to get at - I saw someone with theirs open and the board was only slid out 1-1.5"

Who cares? Your not going to hear the difference unless this mode severely messes with the audio.

Not necessarily... AKM seems to think sound quality mode is better for sound quality. They made a whole pin for it and everything!

 

[mike7877]

My DAC-A26 has this setting exposed as "Listening" and "Monitoring" on the UI. There is small difference audibly between the two. I would measure it, but don't have a capable enough ADC after my last motherboard with PCI slots died and put my e-Mu 1212m out of action.

Cool. How would you say it affects the sound? Just generally - is it the image? Tonal balance?

 

[mike7877]

Yes we do. It is clearly stated in the capture from the datasheet you posted in post #1
View attachment 354252

If the chip is in "register control mode" you would have to tap the i2c pins and read the registers. If in "pin control mode" you could just use a multimeter and measure the voltage at the SC pin. You will need to read the datasheet to see what mode the chip is in. A good guess is checking out if the DAC is connected to a microcontroller or usb bridge or not.

I think it is connected to a USB bridge. I think all of Toppings DACs are. They're usually named XMOS### iirc

 

[Sangram]

Cool. How would you say it affects the sound? Just generally - is it the image? Tonal balance?

It's a slight tonal shift, most of the effect is in the midbass. I'd say about 1dB, so it's sort of blink and you'll miss it. You have to be listening really intently and on intimately familiar material. I would concur that the difference is too slight to be of material use, but some may think different.

 

[MCH]

I think it is connected to a USB bridge. I think all of Toppings DACs are. They're usually named XMOS### iirc

Then, my advice would be to give up. There are a lot of control pins exposed in the E70 but they don't seem to be labelled. It might take you hours to find out what is what, and eventually reading the registers might not be even possible.
Maybe try your luck and ask topping.

Edit:
You can check the voltage in pin 18 in both chips. If high in both chips, then the chips are in pin control mode and you can check the voltage in pin 17 as explained before. If 0V at pin 18 in one of the chips, then it is in register control mode = bad luck

 

[mike7877]

Then, my advice would be to give up. There are a lot of control pins exposed in the E70 but they don't seem to be labelled. It might take you hours to find out what is what they are, and eventually reading the registers might not be even possible.
Maybe try your luck and ask topping.

Yeah, that's probably the best option...
I'll add the answer to this thread if they tell me.

 

[mike7877]

It's a slight tonal shift, most of the effect is in the midbass. I'd say about 1dB, so it's sort of blink and you'll miss it. You have to be listening really intently and on intimately familiar material. I would concur that the difference is too slight to be of material use, but some may think different.

So there is ~1dB more presence in the midbass?

edit: which mode do you use? Is image width affected at all?