Topping D90SE Measurements (DAC)

[theREALdotnet]

So this stuff here, what’s causing it?

Is it to be expected from a 384kHz signal? Like I said, at -135dB and lower it’s not going to be a bother, but it does stick out in this plot.

 

[bennetng]

Pardon my muddled terminology, if anything it would be aliasing, not anti-aliasing artifacts. But yes, from what I understand, aliasing is the result of intermodulation between the signal and the sampling frequency.

Aliasing is a digital term, which means analog conversion is not required to introduce aliasing. For example digital synthesizers and samplers can introduce aliasing artifacts even without analog conversion.

BASSMIDI interpolation quality

BASSMIDI interpolation quality

www.un4seen.com

IMD on the other hand is an analog term, can happen with strictly analog equipment like tube amp and so on.

 

[Music1969]

So this stuff here, what’s causing it?

View attachment 198266

Is it to be expected from a 384kHz signal? Like I said, at -135dB and lower it’s not going to be a bother, but it does stick out in this plot.

That's 100dB of clear range, below the signal (signal at -35dB)?

 

[theREALdotnet]

IMD on the other hand is an analog term, can happen with strictly analog equipment like tube amp and so on.

Intermodulation can always occur when two signals are subjected to a non-linear transfer function, like being multiplied with each other or whatever. It doesn’t matter whether the signals are continuous or sampled.

 

[theREALdotnet]

That's 100dB of clear range, below the signal (signal at -35dB)?

Yes, you’re right. I had assumed the signal peaked at 0dB (that Y axis is a bit hard to read).

 

[bennetng]

From Monty, the presenter of the most frequently posted video on ASR, explained what is IMD:

24/192 Music Downloads are Very Silly Indeed

web.archive.org

Neither audio transducers nor power amplifiers are free of distortion, and distortion tends to increase rapidly at the lowest and highest frequencies. If the same transducer reproduces ultrasonics along with audible content, any nonlinearity will shift some of the ultrasonic content down into the audible range as an uncontrolled spray of intermodulation distortion products covering the entire audible spectrum. Nonlinearity in a power amplifier will produce the same effect. The effect is very slight, but listening tests have confirmed that both effects can be audible.

Above: Illustration of distortion products resulting from intermodulation of a 30kHz and a 33kHz tone in a theoretical amplifier with a nonvarying total harmonic distortion (THD) of about .09%. Distortion products appear throughout the spectrum, including at frequencies lower than either tone.

Inaudible ultrasonics contribute to intermodulation distortion in the audible range (light blue area). Systems not designed to reproduce ultrasonics typically have much higher levels of distortion above 20kHz, further contributing to intermodulation. Widening a design's frequency range to account for ultrasonics requires compromises that decrease noise and distortion performance within the audible spectrum. Either way, unneccessary reproduction of ultrasonic content diminishes performance.

 

[Music1969]

Yes, you’re right. I had assumed the signal peaked at 0dB (that Y axis is a bit hard to read).

So it's not really that great compared to some other DACs.

But may improve with updated firmware that fixes this MQA crap.

 

[theREALdotnet]

From Monty, the presenter of the most frequently posted video on ASR, explained what is IMD:

Yes, I’ve read it. It kind of poses more questions than it answers, though, for example:

Either way, unneccessary reproduction of ultrasonic content diminishes performance.

Given that audible vs ultrasonic is an arbitrary distinction as far as signal processing is concerned, doesn’t this mean we would gain higher performance if we limited the bandwidth of ADCs and DACs even further to, say, 18kHz?

 

[bennetng]

Either way, unneccessary reproduction of ultrasonic content diminishes performance.

That was what Monty said, not mine. In my opinion, since DACs these days often offer different filters, users can have their own choices depend on their preferences and audio content being played.

 

[VintageFlanker]

Is it to be expected from a 384kHz signal?

Signal (DAC) is 44.1Khz.
ADC is set @384.Khz.
Then, you see the full 192Khz bandwidth.

As requested by @Music1969.

 

[Music1969]

Signal (DAC) is 44.1Khz.
ADC is set @384.Khz.
Then, you see the full 192Khz bandwidth.

As requested by @Music1969.

Yes requested 44.1kHz signal because >> 90% music still 44.1kHz

 

[Music1969]

Have you ever seen Topping release firmware updates?

Isn't this Matrix DAC?

 

[srkbear]

Isn't this Matrix DAC?

It’s a Topping D90se forum—perhaps I came in late in the discussion? I’ll go further back, thanks!

 

[theREALdotnet]

It’s a Topping D90se forum—perhaps I came in late in the discussion? I’ll go further back, thanks!

But yes, they do sometimes release firmware updates:

Download - TOPPING

TOPPING

www.tpdz.net

 

[srkbear]

But yes, they do sometimes release firmware updates:

Download - TOPPING

TOPPING

www.tpdz.net

I’ve been to that site innumerable times—they release updated drivers, but actual firmware upgrades almost never, if at all. It’s my only criticism of Topping, that they don’t respond to consumer feedback and refresh their gear, and the other salient Chinese manufacturers behave similarly. Fortunately I’m happy with my D90se, but I’d prefer that they revisit their work every so often.

 

[Music1969]

It’s a Topping D90se forum—perhaps I came in late in the discussion? I’ll go further back, thanks!

Yes you missed a lot of context

 

[Sonic-Wall]

@srkbear
Maybe you should replace your Topping with a RME ADI-2.
They provide firmware updates on a regular base with lot‘s of enhancements.

 

[srkbear]

@srkbear
Maybe you should replace your Topping with a RME ADI-2.
They provide firmware updates on a regular base with lot‘s of enhancements.

I love my Topping, but thanks!

 

[Sonic-Wall]

Just tried to help you saving your precious time and enjoy your music;-)

 

[srkbear]

Just tried to help you saving your precious time and enjoy your music;-)

I’ve considered the RME innumerable times. It’s a great unit! Love the DSP features. If I didn’t already have a dedicated amp (the iFi Pro iCAN Signature) with it’s own analog bass enhancements and the DSP functions of Roon, I’d go for it—and although I try to remain closeted about it, I have a lot of very good masters in MQA format that I’d miss with the RME. Perhaps when I decide to outfit another room in my house with audio, I’ll reconsider. Peace!