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is Naim Pre-Amp necessary with i-tunes?

No, I was answering the OP...

The question was do you need a pre-amp between a computer and a power amp, or could you just plug the computer straight into the power amp.

And I responded that I would not do that, and gave a pretty obvious practical reason.


But your practical reason depended on the presence of an attenuator, not an amplifier, so by adding a pre-amp you make your problem worse. (more amplification = louder noise)

Only an attenuator will reduce your practical problem, hence my explanation that in legacy systems the attenuator was usually present in the pre-amp, but in digital systems it doesn't have to be, so the pre-amp is un-necessary.

I think you are confusing the functions of an amplifier and an attenuator.

JC
 
But your practical reason depended on the presence of an attenuator, not an amplifier, so by adding a pre-amp you make your problem worse. (more amplification = louder noise)

Only an attenuator will reduce your practical problem, hence my explanation that in legacy systems the attenuator was usually present in the pre-amp, but in digital systems it doesn't have to be, so the pre-amp is un-necessary.

I think you are confusing the functions of an amplifier and an attenuator.

JC
I think you don't know what a pre-amp is.
Perhaps you should read the specifications of some products and get to know what the output voltages are of sources and pre-amps.
You might learn something.
 
Nik, do you accept this statement ?
Given that we are reducing the bit depth and that fewer bits means lower resolution, I'd have to say, "it depends".

If we reduce the volume it is quite likely that the lower resolution will not be audibly apparent. If, however, we were to add gain later in the chain so that the volume is the same as it would be with no digital attenuation, then I'd expect it to be audible. If not, we are implicitly saying that 13 bit (or 10 bit, or whatever) is just as good as 16.
 
I think you don't know what a pre-amp is.
Perhaps you should read the specifications of some products and get to know what the output voltages are of sources and pre-amps.
You might learn something.

Ha Ha, you are trolling as usual. - JC.
 
If your room is quiet, and your amps modern, perhaps the quietest end of the range is at 30dB. The maximum ever needed might then be at 110dB. So 80dB range, which is a signal ratio of 10000, about 14 bits.

I don't see any problem in principle with digital attenuators. However I think they should be designed in conjunction with upsampling and possibly bit extension. So 16 bits at 44k1 goes in and 24 bits at 176 or 352 comes out. That way we don't add noise or distortion and preserve the dynamic range of the input beyond audibility.

I use a DAC with an integral digital attenuator, it seems to work well at all output levels, it obviously tracks perfectly at all output levels and the control law is implemented in software so the range of the control is very usable.

Paul
 
Given that we are reducing the bit depth and that fewer bits means lower resolution, I'd have to say, "it depends".

If we reduce the volume it is quite likely that the lower resolution will not be audibly apparent. If, however, we were to add gain later in the chain so that the volume is the same as it would be with no digital attenuation, then I'd expect it to be audible. If not, we are implicitly saying that 13 bit (or 10 bit, or whatever) is just as good as 16.

The simple fact is nik, that by using a 16 bit source signal, and employing a 24 bit mixer, or level control, we are not 'reducing the bit depth' as you term it.

Firstly 16 bit systems, such as CD can play quiet passages just as easily as loud ones without any distortion or 'loss of resolution' occurring at all. All 16 bit music files display this ability.

The problem occurs only when you want to change the level by effectively making a new file by employing a mathematical calculation on all the word samples.

The remedy is to increase the word-length to 24 bits, which admittedly adds 'empty' information, apply dithering to remove quantisation error, and down-sample to 16 bit for consumption as a 16 bit file.

Totally transparent level reduction results, whilst preserving full bit depth and resolution.

Daniel Weiss understands how to do this and so do the Apple and Microsoft engineers.

Weiss (and Keith) is quite correct that 24 bit digital level controls are transparent and you need have no fears about distortion or loss of resolution.

Most new professional recording and mixing equipment used to make recordings these days uses these techniques, and the finished results are better than anything previously available.

Try some. :)

JC.
 
p.s. btw, you don't have to down-sample back to 16 bit if you don't need to. Simply use the resulting file at 24/44, or 24/88, or 24/176, or whatever you like ......

It will have all the resolution of the original 16 bit file.

JC
 
p.p.s. Nyquist and Shannon at the Bell Telephone Labs had got all the arithmetic of this sorted in 1948.

It just took the manufacturers of digital hifi equipment some time to perceive that implementation was necessary.

Bell Labs info

JC
 
Ha Ha, you are trolling as usual. - JC.
No - merely pointing out that you don't know what you are talking about.

For instance, you say:

p.p.s. Nyquist and Shannon at the Bell Telephone Labs had got all the arithmetic of this sorted in 1948.

It just took the manufacturers of digital hifi equipment some time to perceive that implementation was necessary.

Bell Labs info

JC
But as I recall from my Electronics degree course, Shannon's Sampling Theorem gave a theoretical basis for sampling based on a perfect A-D and D-A capability.

The problem you have is that you don't seem to be able to understand that the real world implementations cannot achieve that.

It's similar to when you regurgitate the information from component specification sheets rather than the real-world performance of their implementations.

So, when you displayed your ignorance of what an amplifier is by saying:

But your practical reason depended on the presence of an attenuator, not an amplifier, so by adding a pre-amp you make your problem worse. (more amplification = louder noise)

Only an attenuator will reduce your practical problem, hence my explanation that in legacy systems the attenuator was usually present in the pre-amp, but in digital systems it doesn't have to be, so the pre-amp is un-necessary.

I think you are confusing the functions of an amplifier and an attenuator.

JC
I suggested to you that you do a bit of research and read some of the spec sheets you seem to favour, because you will find out that a pre-amplifier tends to not make the music louder (eg. if the source is a CD player or DAC, it will output something like 2V peak, which is roughly what the peak out of a pre-amp would be).

I also said that I made no mention of the implementation of the pre-amp (active/passive/digital), but you felt the need to be a bit clever and say "attenuator", which Jack Barriere pointed out is precisely what a passive pre-amp is.

You like to present yourself as a bit of a guru, but your arguments are flawed, and pointing that out is not trolling.

Sorry to burst your bubble.
 
More thread craps as usual Paul. You can think what you like. It doesn't seem to get you anywhere.

Just go and get some experience with good digital kit and you'll find the level controls are fine and don't cause any problems.

JC
 
More thread craps as usual Paul. You can think what you like. It doesn't seem to get you anywhere.

Just go and get some experience with good digital kit and you'll find the level controls are fine and don't cause any problems.

JC
You said some things that were wrong and I've pointed them out; you know they were wrong and your usual defence mechanism kicks in and you avoid the questions and start the ad-hom.

The thread isn't about your great digital kit debate; it is about whether a pre-amp is required, so you are arguing with yourself on that one.

I would suggest that you go back to page 1 and read the OP, and then decide whether to answer the question. (You could then start up a separate thread about the actual topic you wish to discuss.)
 
They aren't wrong Paul, you are just pointlessly creating argument, and acting like a troll as usual.

A pre-amp is not necessary, as I have said, and has been proven.

The consequence of not using a traditional legacy analogue pre-amp is that you have to depend on a digital volume control, either in the computer, or in the dac.

There is nothing wrong with doing that, since with modern, current, 24bit digital volume controls there is no degradation in sound quality, as also has been proven.

Go and visit Keith at Purite Audio and he will show you one working. He has posted his assurance that it is totally transparent.

This is a complete answer to the OP's question.

It's just that you don't like the answer.

JC.
 
They aren't wrong Paul, you are just pointlessly creating argument, and acting like a troll as usual.

A pre-amp is not necessary, as I have said, and has been proven.

The consequence of not using a traditional legacy analogue pre-amp is that you have to depend on a digital volume control, either in the computer, or in the dac.

There is nothing wrong with doing that, since with modern, current, 24bit digital volume controls there is no degradation in sound quality, as also has been proven.

Go and visit Keith at Purite Audio and he will show you one working. He has posted his assurance that it is totally transparent.

This is a complete answer to the OP's question.

It's just that you don't like the answer.

JC.
JC - you are always having to personalize things (and of course accuse people of trolling when they point out you are wrong).

I spoke about a pre-amp without specifying whether it should be analogue, digital, active, or passive.

You chose to try and turn that into an opportunity to argue against an analogue pre-amp (and got yourself in a bit of a muddle in the process).

But nobody said it had to be analogue in the first place (I certainly didn't), so you were just trying to contrive a basis for something to argue about - a so-called strawman.
 
The lengths you are going to, to keep this going, is bordering on the psychotic Paul.

You need help.

JC.
 


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