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Does the amplifier amplify the noise?

DanielT

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An amplifier will amplify anything presented to its input jacks. It will also add noise/distortion of its own, but with a good design these would not be a concern.
 

Holmz

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Edit:
By the way, I have tried to reduce that type of hum on an old NAD3020 amp. With extra screws between chassis and transformer, rubber plates between transformer and chassis. It did not help.Used, a lot of sound for the money but new Hifi undeniably has its advantages.
…]

Those amp are workhorses. and I suspect that they could measure well.
 

solderdude

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My conclusion would be that the bad SNR of a noisy DAC can't be removed by an amplifier, no matter how good. Of course, in the case of a perfect dac with a noisy amplifier, the amplifier would add noise to the perfect signal (that is rather obvious). So the DAC and the amp should in theory have similar noise performance so that "no performance gets wasted".

post #2 sums it up perfectly.

I will get into the theory and say Yes and No(in practice).
For instance practice will show that all recordings out there have noise levels exceeding your theoretical -100dB so the contribution of the DAC will be negligible in reality.
Also the amp may have a volume control which changes situations.
When volume is controlled digitally your theory is correct.

Suppose the DAC has -100dB noise floor (which is good and not crappy) and we have an amp that does not add distortion nor noise.
In practice you will not be listening to 100dB 1kHz yet the DAC outputs that.
In reality you will be using the volume control of your amp you will be attenuating the noise + signal and the noise would thus drop in level when the volume is turned down. You keep the 100dB S/N ratio (with a perfect amp that, again in reality, does not exist).

In case of digital volume control (or the DAC being perfect and amp adding -100dB) the situation alters.
Noise will always be at the same level and only the signal will change amplitude. This will alter the S/N ratio depending on how loud the music plays.
 
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DanielT

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Those amp are workhorses. and I suspect that they could measure well.
I have in mind that it is said that the NAD3020 was the bumblebee that could fly. The build quality was a bit so and so. It was a budget amp.
Anyway, a fun little racer . :D How such an old amp would measure would have been fun to see. Anyone have one that can be sent to Amir? If Amir feels like measuring up a NAD3020, if there is a general interest in taking part in such meetings, that is.

The NAD 3020 is a stereo integrated amplifier by NAD Electronics, considered to be one of the most important components in the history of high fidelity audio.[1] Launched in 1978, this highly affordable product delivered a good quality sound, which acquired a reputation as an audiophile amplifier of exceptional value. By 1998, the NAD 3020 had become the most well known and best-selling audio amplifier in history.[2]


Enough with OT about NAD3020, back to the topic of the thread.:)
 
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tvrgeek

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Proof please... where is your controlled ABX result? Without same, it's simply your perception and you cannot prove it to anyone else.


JSmith
THERE IS ALWAYS ONE. I DON'T NEED TO PROVE ANYTHNG TO YOU. IF YOU BELIEVE THEY ARE ALL THE SAME, WHY ARE YOU HERE?
IF YOU BELIEVE WE KNOW EVERYTHNG AND CAN MEASURE EVERTYTHING, THEN YOU HAVE NOTHING ELSE TOLEASRN. SOME OF ARE NOT SO NARROW MINDED.
 

SaltyCDogg

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THERE IS ALWAYS ONE. I DON'T NEED TO PROVE ANYTHNG TO YOU. IF YOU BELIEVE THEY ARE ALL THE SAME, WHY ARE YOU HERE?
IF YOU BELIEVE WE KNOW EVERYTHNG AND CAN MEASURE EVERTYTHING, THEN YOU HAVE NOTHING ELSE TOLEASRN. SOME OF ARE NOT SO NARROW MINDED.
that escalated quickly.

Isn't this the general mission of this site. That ultimately we're all flawed human beings who will perceive, especially when it comes to audio, changes/improvements etc that aren't real. So when someone makes claims that are likely not supported by science they can expect to be challenged.
 

tvrgeek

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I do not favor digital volume controls. By definition, you are decreasing resolution. This is why studios record in 32 bit, to have the additional resolution they can "waste" so we can get a full 16 bit result.

A digital volume control will change the SOURCE noise floor just as it changes the music. Today, noise should be the least of one's worries. If any equipment is so bad it adds audible noise move on. Maybe phono stage but they only need to be below a record which is about -60dB. SNR of 90 to 100dB for anything these days is minimal. Most better. I know several $100 DACS that wil lnot add audible noise. One sound very nice too.
 

BoredErica

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THERE IS ALWAYS ONE. I DON'T NEED TO PROVE ANYTHNG TO YOU. IF YOU BELIEVE THEY ARE ALL THE SAME, WHY ARE YOU HERE?
IF YOU BELIEVE WE KNOW EVERYTHNG AND CAN MEASURE EVERTYTHING, THEN YOU HAVE NOTHING ELSE TOLEASRN. SOME OF ARE NOT SO NARROW MINDED.
You're in ASR not SBAF or Headfi. If you can't accept people doubting your experiences, consider whether you even want to be here.

Also again with the shouting in another thread. Please stop it.
 

tvrgeek

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that escalated quickly.

Isn't this the general mission of this site. That ultimately we're all flawed human beings who will perceive, especially when it comes to audio, changes/improvements etc that aren't real. So when someone makes claims that are likely not supported by science they can expect to be challenged.
Sick and tired of this arrogant "I know all" asking for impossible proofs they darn well know is impossible.

Got a few hundred thousand dollars for test equipment we can borrow? Want to put up a few dozen in a hotel and maybe get a university to manage a test? Fine.. Call me when it is ready. I know what I hear.

There differences that our current tests do not fully describe. I even know how to measure some of them. The goals SHOULD be to discover and quantify them, then determine which errors cause what perceptions. TO deny they exist is contra to that goal.
 

JSmith

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I DON'T NEED TO PROVE ANYTHNG TO YOU.
If your going to make grandiose claims, then yes, you need to have some evidence here at ASR apart from your ears/brain and a vocabulary. There is plenty of information on this site to assist you in performing basic level matched comparisons, you just can't know which is which at any given time.

jonah-hill-shriek.gif



JSmith
 

tomtoo

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Its all said by @solderdude.

DACs are not very noisy. Even the not so expensive ones. So if people try to complain over the noise level of a good measuring DAC they please should never ever try vienyl. Never!
 

tvrgeek

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If your going to make grandiose claims, then yes, you need to have some evidence here at ASR apart from your ears/brain and a vocabulary. There is plenty of information on this site to assist you in performing basic level matched comparisons, you just can't know which is which at any given time.

jonah-hill-shriek.gif



Nothing grandiose about what I hear. Mo magical claim, no magic snake oil involved. I know what I hear and do not like being called a liar. I will yell when it is appropriate to arrogant know it all's like you.
 

solderdude

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Sick and tired of this arrogant "I know all" asking for impossible proofs they darn well know is impossible.

Not impossible at all, but alas the proof will only be proof for you. You cannot possibly satisfy others so you only do this for yourself, not for others.
You just need to be willing to test in different ways than you are used to which may require ingenuity and some basic measurements.

When differences are real they can be proven without a shadow of a doubt.
When they come from perception 'errors', even that can be proven but is hard to swallow as it would mean having to admit to yourself you have been wrong about things that were a guaranteed certainty before.
It is sobering and many will never admit it even with their noses rubbed into it.
 

Holmz

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Sick and tired of this arrogant "I know all" asking for impossible proofs they darn well know is impossible.

Got a few hundred thousand dollars for test equipment we can borrow? Want to put up a few dozen in a hotel and maybe get a university to manage a test? Fine.. Call me when it is ready. I know what I hear.

There differences that our current tests do not fully describe. I even know how to measure some of them. The goals SHOULD be to discover and quantify them, then determine which errors cause what perceptions. TO deny they exist is contra to that goal.

You make it sound difficult.

One could capture the output of a couple of different units and compare those in both the frequency and time domain.
If for instance…
Yes, there are those who say the DAC does not matter. Their belief. Some of us know that is not true. :) I know the Atom DAC+ has a smoother midrange and less "glare" than my Schiit, Topping, Muse, or Focusrite.
^This^ was true, then it is possible that the “Glare” could be an elevated high frequency,
or
That the “Glare” might be seen in the time domain.

If you showed ^that^, it would prove that there was a difference.
or
If you showed that out of 10-20 times of the blind test, you could pick out the Atom DAC+ more than just chance… then that would also have some weight to it.

However, as it stands, it is mostly a just a story.
But it is still possible that what you say is true.
 

Holmz

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I have in mind that it is said that the NAD3020 was the bumblebee that could fly. The build quality was a bit so and so. It was a budget amp.
Anyway, a fun little racer . :D How such an old amp would measure would have been fun to see. Anyone have one that can be sent to Amir? If Amir feels like measuring up a NAD3020, if there is a general interest in taking part in such meetings, that is.

The NAD 3020 is a stereo integrated amplifier by NAD Electronics, considered to be one of the most important components in the history of high fidelity audio.[1] Launched in 1978, this highly affordable product delivered a good quality sound, which acquired a reputation as an audiophile amplifier of exceptional value. By 1998, the NAD 3020 had become the most well known and best-selling audio amplifier in history.[2]


Enough with OT about NAD3020, back to the topic of the thread.:)

I have one in 230v (ear… the Mrs actually has it).

We could test it if:
  • @amirm has a 120->230 transformer
  • You pay half the shipping (it should be about 50 USD each.)
  • The Mrs says, “ok”.
Alternatively I could probably test it, one channel at a time, by capturing the output into a sound card.
 

restorer-john

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I have in mind that it is said that the NAD3020 was the bumblebee that could fly. The build quality was a bit so and so. It was a budget amp.
Anyway, a fun little racer . :D How such an old amp would measure would have been fun to see. Anyone have one that can be sent to Amir? If Amir feels like measuring up a NAD3020, if there is a general interest in taking part in such meetings, that is.

The NAD 3020 is a stereo integrated amplifier by NAD Electronics, considered to be one of the most important components in the history of high fidelity audio.[1] Launched in 1978, this highly affordable product delivered a good quality sound, which acquired a reputation as an audiophile amplifier of exceptional value. By 1998, the NAD 3020 had become the most well known and best-selling audio amplifier in history.[2]


Enough with OT about NAD3020, back to the topic of the thread.:)

The NAD 3020 was a piece of absolute plastic garbage. I've probably had a few dozen through my hands over the years. The original did not deserve to see the light of day. By the time they got to the "3020i" it was passable, just.

There is nothing good about the original, then or now.
 

BDWoody

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THERE IS ALWAYS ONE. I DON'T NEED TO PROVE ANYTHNG TO YOU. IF YOU BELIEVE THEY ARE ALL THE SAME, WHY ARE YOU HERE?
IF YOU BELIEVE WE KNOW EVERYTHNG AND CAN MEASURE EVERTYTHING, THEN YOU HAVE NOTHING ELSE TOLEASRN. SOME OF ARE NOT SO NARROW MINDED.

No need to start with the shouting...

Funny that with all your technical acumen, you don't believe in the value or importance of listening controls.

If you don't want to be challenged, don't make the claims. Simple.

Maybe accept these comments in the 'dope slap' category meant to help. You are happy to dish them out...can you take it too?

Sometimes a "dope slap" can really open one's eyes and due to the initial question, it was needed. He can choose to waste his money, or he can get the facts. In some cases, it is a disservice to be too nice.

I am too old to reman all sweet and cuddly. Too many years having to be "perfect" as a DoD manager. Retirement means I am allowed to be a curmudgeon.
 
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Holmz

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The NAD 3020 was a piece of absolute plastic garbage. I've probably had a few dozen through my hands over the years. The original did not deserve to see the light of day. By the time they got to the "3020i" it was passable, just.

There is nothing good about the original, then or now.

All that may be true, but they sold a million of these things, so it had a following of sorts.
 

DanielT

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I have one in 230v (ear… the Mrs actually has it).

We could test it if:
  • @amirm has a 120->230 transformer
  • You pay half the shipping (it should be about 50 USD each.)
  • The Mrs says, “ok”.
Alternatively I could probably test it, one channel at a time, by capturing the output into a sound card.
The NAD 3020 was a piece of absolute plastic garbage. I've probably had a few dozen through my hands over the years. The original did not deserve to see the light of day. By the time they got to the "3020i" it was passable, just.

There is nothing good about the original, then or now.

He he, this can be exciting. Do you test Holmz, most easily so.:)

The build quality is probably lousy. There are several who mentioned that this is the case, I do not doubt about that but is there a bumblebee that can fly despite that? That is, does it measure reasonably ok or not?:)
 
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