Noob question about DACs and AMPs

[GPRD]

Hello!

This may very well be a silly question for some who handle data and its relevance in audio knowledgeably, but I have had a doubt about the SNR of the tests conducted for some time.
I understand that SNR values are very relevant because comparative graphs between devices are based on them, and I interpret that the higher the value, the better. So far so good.
Now, amplifier graphs are rated as excellent between values of 95 to 113 (there's a Topping SNR 120) but DACs are excellent between values of 109 to 124 SNR.

My questions are as follows:
Why is so much importance given to the SNR of the DAC if most devices cannot replicate its quality?
Does it add any value to input a signal from a DAC with, for example, an SNR of 115 into an amplifier with an SNR of 100? ¿Are those 15 SNR points of sound or information lost?
Does an amplifier with an SNR of 95 sound exactly the same with a DAC of 115 SNR as an amplifier of 95 and a DAC of 95 SNR?

I apologize if the questions are very silly, but it will help me understand the pairing between devices.
Thank you very much in advance.

 

[Doodski]

Why is so much importance given to the SNR of the DAC if most devices cannot replicate its quality?

It indicates the engineering quality of the devices and of course indicates that hiss and noise is non-existent.

Does it add any value to input a signal from a DAC with, for example, an SNR of 115 into an amplifier with an SNR of 100? ¿Are those 15 SNR points of sound or information lost?
Does an amplifier with an SNR of 95 sound exactly the same with a DAC of 115 SNR as an amplifier of 95 and a DAC of 95 SNR?

They are all above your threshold of hearing and so not mattering much but every improvement helps and indicates quality.

 

[Rja4000]

Hi
Welcome for your very first post

2 points :

1. Degradation is (statistically) additive.
So if you want to reach a certain total degradation target, every component has to be better than this total by a margin.
If your target is CD quality (which should be around 96dB SINAD) for your electroncs, each component has to beat that.

A SINAD of 115dB combined with a SINAD of 95dB means a total SINAD around... 95dB.
A SINAD of 95dB combined with a SINAD of 95dB means a total SINAD around... 92dB.

2. In 2025, good quality DACs cost nothing.
I mean, not more than bad performance DACs.

So, why not to avoid degrading your chain by using a good DAC ?
That's way cheaper than a better amp.

 

[gvl]

Valid points, but DACs have to be stacked by performance somehow, hence the SINAD-based ranking/chart.

 

[unpluggged]

Hello!

This may very well be a silly question for some who handle data and its relevance in audio knowledgeably, but I have had a doubt about the SNR of the tests conducted for some time.
I understand that SNR values are very relevant because comparative graphs between devices are based on them, and I interpret that the higher the value, the better. So far so good.
Now, amplifier graphs are rated as excellent between values of 95 to 113 (there's a Topping SNR 120) but DACs are excellent between values of 109 to 124 SNR.

My questions are as follows:
Why is so much importance given to the SNR of the DAC if most devices cannot replicate its quality?
Does it add any value to input a signal from a DAC with, for example, an SNR of 115 into an amplifier with an SNR of 100? ¿Are those 15 SNR points of sound or information lost?
Does an amplifier with an SNR of 95 sound exactly the same with a DAC of 115 SNR as an amplifier of 95 and a DAC of 95 SNR?

I apologize if the questions are very silly, but it will help me understand the pairing between devices.
Thank you very much in advance.

The graphs are not about SNR, they are about SINAD. Why SINAD is so important is because this is the primary performance metric of a sound reproduction system. If it is too low, the DUT cannot be considered as transparent.

 

[AnalogSteph]

Why SINAD is so important is because this is the primary performance metric of a sound reproduction system.

Well, I wouldn't call it important as such... it's a handy single number metric that, once high enough, will tell you that you won't have to worry about either noise or distortion (now those are the important bits), and can serve as an indicator of engineering quality. It doesn't really tell you much beyond that. Going off of SINAD alone can be wildly pessimistic or even misleading.

All of this assumes that you have gotten past the hurdle of basic frequency response, which is generally assumed to be dead flat (although this is not truly always the case).

 

[DVDdoug]

The graphs are not about SNR, they are about SINAD.

Unless something is terribly defective (or "overdriven") you're NEVER going to hear distortion. (And speakers or headphones usually have way more distortion than electronics). Noise is the real concern (hum, hiss or whine in the background).

It's tricky because the real question is if you can hear the noise or not, and if you can hear it, how loud it is. You need the "ratio" for a signal reference. Of course, it's most audible with no "signal" or during quiet or "silent" parts of the program and at low levels the actual S/N (or SINAD) is worse because the noise remains the same as the signal goes down. The audibility of the noise also depends on the amount of amplification, the sensitivity of your speakers (or headphones), how close you are to your speakers, acoustic background noise, etc.

The S/N or dynamic range of digital is also a bit tricky because quantization noise (-96 or -93dB at 16-bits) only exists when there is a "signal". The digital silence between tracks has no noise (minus infinity dB), but there is still noise from the analog-side of the DAC.