Why do head-fiers ignore the Preamp?

[chesebert]

It's kind of a big deal.

You got special needs not applicable to the general community

 

[chesebert]

Or set the pot to max (to have same resistors in and ground and essentially make a full passthrough) and put a nice preamp of your choice. Schiit Saga as a pre to my headphone amp is such a delight to use! I get full remote control so I can even relax on my couch without ever leaving it to increase and decrease the volume!

Adding remote control functionality makes sense - you are trading quality for convenience, a fine choice.

 

[gregorio]

The preamp will undoubtably improve sound in a larger, easier to hear way than most dacs.

Unless the amp being used is broken or the wrong amp for the particular HPs, a “preamp will undoubtedly” degrade the sound, unless it somehow breaks the laws of physics!

Yet, most head-fiers ignore this vital part of the system. They seem to think it is for speakers only.

Of course they ignore it, because it is not a “vital part of the system”. A system does not need a preamp and the very best (most accurate/high fidelity) systems do not use preamps, so how is a preamp “vital”? And, speakers require tens, hundreds or even thousands of Watts, while headphones only need Milli-Watts, so of course people “seem to think it is for speakers only”!

For sources like DACs, the output can be fixed, then there are those that argue, some DACs can drive power amps directly.

Well of course. DACs designed to drive a power amp will of course drive a power amp unless it’s faulty (or the amp is).

To counter that argument, it is safer for tweeters to have a preamp running at -40db and a DAC out of control, rather than an out of control DAC that blasts 0db direct to a power amp.

If a DAC is “out of control” then it’s broken and needs replacing. Using a preamp doesn’t fix a broken DAC. Also, 0dB is zero decibels, how can you “blast” nothing at all “direct to a power amp”? You seem to be confusing the digital scale with some analogue scale. Unless it’s seriously broken, a DAC will output roughly line and unless an amp is broken (or designed for a different task), it will operate optimally with a roughly line level input. This “argument” doesn’t make any sense and therefore does not “counter” your previous quoted argument.

Faults like that are rarely the DAC's fault but the player software 'loses it' and spits out white noise.

If a DAC is “out of control” and therefore broken, then of course it’s the “DAC’s fault”. If you feed a DAC an overload signal to start with, then obviously it’s the “fault” of the user or a serious bug/error in the source (or whatever is feeding the source).

I get that some people might like the look of having an extra, unnecessary box as part of their setup but a preamp will not improve the sound, at best it will make no audible difference.

G

 

[Strayngs]

Unless the amp being used is broken or the wrong amp for the particular HPs, a “preamp will undoubtedly” degrade the sound, unless it somehow breaks the laws of physics!

I guess every amp I've tried with a preamp has been broken then lol. And laws of physics? Really? LOL! Please please inform me. Give me the exact law of physics that discusses volume control from a preamp versus a dac only lol.

I think most of the people who are against preamps don't know what they're doing matching them to an amp. If you have a hot dac, you don't want to preamp. Improper impedance match or too much gain will absolutely hurt the sound. So with headphones, the best way to do a preamp is

1. verify that the impedance works between preamp and amp
2. The best choice is with variable voltage output in a dac and to have a preamp that has multiple gain selections.
3. Then you just play with all your available options till you get the right match.

This does limit what you can do dac wise and preamp wise. Some of these things are not nearly as important with speakers. So if you're referring to these matchup issues as laws of physics, than yes, there is some truth to what you say. I think it's a whole lot of work and you may not be able to use the exact equipment you might prefer. And I think this is the primarily reason the preamp isn't used much. But if these steps are taken carefully taken, there is a great reward.

 

[theveterans]

Unless the amp being used is broken or the wrong amp for the particular HPs, a “preamp will undoubtedly” degrade the sound, unless it somehow breaks the laws of physics!

This is too general IMHO and there are well designed preamps out there that helps boost the signal without increasing noise floor in the slightest. This can improve the dynamic range of the power amp and may result to what some people here perceive as better sonically

The caveat is that the impedance stay flat across the frequencies which is not so easy to achieve with an active preamp

 

[gregorio]

I guess every amp I've tried with a preamp has been broken then lol.

Either that or what you’re hearing is not an improvement but you seem to think it is, lol.

And laws of physics? Really? LOL!

Yes, REALLY. lol.

Please please inform me. Give me the exact law of physics that discusses volume control from a preamp versus a dac only lol.

You’ve never heard of the laws of thermodynamics and you’re laughing at me? Now that really is funny! The laws of thermodynamics dictate that the motion of electrons in a circuit will create noise, as calculated by Johnson/Nyquist (hence why it’s called Johnson or thermal noise). Sticking another amp (preamp) and therefore more cables, connectors, circuits in the analogue chain will therefore increase noise.

I think most of the people who are against preamps don't know what they're doing matching them to an amp.

You don’t need to match a preamp to an amp, they’re designed to be connected to an amp. The clue is in the name, lol!

If you have a hot dac, you don't want to preamp.

What “hot DAC”, is that like an “out of control DAC”, lol. If a DAC has a line level output then it’s not hot. Even if it has a slightly hotter output than line level, that still won’t matter, assuming you haven’t got a very badly designed amp.

If you have a hot dac, you don't want to preamp. Improper impedance match or too much gain will absolutely hurt the sound.

What “improper impedance match or too much gain”? Show me a DAC with such a thing!

1. verify that the impedance works between preamp and amp
2. The best choice is with variable voltage output in a dac and to have a preamp that has multiple gain selections.
3. Then you just play with all your available options till you get the right match.

All incorrect, lol.
1. What do you think a preamp is designed to connect to?
2. The best choice is a DAC with a line level output and an amp with a line level input. Which is all of them! lol
3. No, you just plug the line level output of your DAC into the input of the amp.

Some of these things are not nearly as important with speakers.

The only potential reason to use a preamp is if you’re using speakers because speakers require significantly more power than HPs, didn’t you know that?

I think it's a whole lot of work and you may not be able to use the exact equipment you might prefer. And I think this is the primarily reason the preamp isn't used much.

The primary reason is because it’s more work, it adds noise and you’re paying extra with a preamp to lower fidelity! lol

But if these steps are taken carefully taken, there is a great reward.

The “great reward” of more thermal noise. lol!

G

 

[gregorio]

This is too general IMHO and there are well designed preamps out there that helps boost the signal without increasing noise floor in the slightest.

Not unless they break the laws of physics! It is simply impossible, there will always be more thermal (Johnson) noise.

G

 

[theveterans]

Not unless they break the laws of physics! It is simply impossible, there will always be more thermal (Johnson) noise.

G

Question is will someone pass a double blind test with the increased thermal noise? Sighed for me between a passive preamp (schiit sys) and direct to amp yielded zero difference but an active preamp yielded sonic difference volume matched and even making the volume on the active preamp lower to purposely decrease its dynamic range and it still sounded different compared to direct. Better or worse sonically is subjective of course. Now I don’t have a measurement of how flat the impedance of the active preamp across frequencies and if it’s non-linear, there’s the obvious sonic difference explanation

 

[Strayngs]

You don’t need to match a preamp to an amp, they’re designed to be connected to an amp. The clue is in the name, lol!

This is all I need to read from you to know you are misinformed, and it is clear you are not interested in learning. I wish you happy listening my friend.

 

[Alien HP]

Most dacs and amps with volume control have a subpar preamp if you compare it to a higher end serious preamp. The preamp will undoubtably improve sound in a larger, easier to hear way than most dacs. Yet, most head-fiers ignore this vital part of the system. They seem to think it is for speakers only.

If you havent tried a preamp with your higher end system….you must try it! I can stress this enough.

Correct me if I am wrong, but I am not sure if it's necessary. And definitely not vital at all. I am using the Topping E70 Velvet DAC with a fixed output level connected to the Violectric V550 amp. The DAC has a preamp feature with a variable output control. But I am not sure I see a reason to use it in my chain above. As advertised on the Topping web site, the preamp feature can be used for a power amp or monitor speakers which is not my use case. The V550 amp has a preamp feature too. I suppose it's higher quality than the E70 Velvet. Using the logic in the quote, I could get another V550 and use it as a preamp placing it in between the E70 DAC and the other V550 used as an amp. But I don't see any sense in doing that. If I wanted a different flavor, I think I would just replace the existing amp or DAC instead of adding another piece to the chain.

 

[Strayngs]

Correct me if I am wrong, but I am not sure if it's necessary. And definitely not vital at all. I am using the Topping E70 Velvet DAC with a fixed output level connected to the Violectric V550 amp. The DAC has a preamp feature with a variable output control. But I am not sure I see a reason to use it in my chain above. As advertised on the Topping web site, the preamp feature can be used for a power amp or monitor speakers which is not my use case. The V550 amp has a preamp feature too. I suppose it's higher quality than the E70 Velvet. Using the logic in the quote, I could get another V550 and use it as a preamp placing it in between the E70 DAC and the other V550 used as an amp. But I don't see any sense in doing that. If I wanted a different flavor, I think I would just replace the existing amp or DAC instead of adding another piece to the chain.

I agree that I dont think there is a benefit for you using the preamp in your Topping. While Topping is high value really good stuff, the preamp in that dac is going to be digital. I dont think it would be any better than the volume control section of your Violectric. But since you have it….doesnt hurt to experiment and find out for yourself what you prefer!!

 

[gregorio]

Question is will someone pass a double blind test with the increased thermal noise?

Assuming it’s a good quality (high fidelity) preamp then the additional thermal noise should be below audibility, hence why I stated “at best it will make no audible difference”.

Better or worse sonically is subjective of course.

Higher fidelity is objective, not subjective. Of course some audiophiles seem to prefer lower fidelity, in which case more noise (and/or distortion) would be subjectively “better” for them.

This is all I need to read from you to know you are misinformed, and it is clear you are not interested in learning.

A preamp isn’t designed to be connected to an amp, got it. Why is it called a PRE-amp then? And as you mentioned “misinformed”, remind who was mocking because he hasn’t heard of even the most fundamental laws of physics and clearly isn’t “interested in learning”? lol

G

 

[Strayngs]

A preamp isn’t designed to be connected to an amp, got it. Why is it called a PRE-amp then? And as you mentioned “misinformed”, remind who was mocking because he hasn’t heard of even the most fundamental laws of physics and clearly isn’t “interested in learning”? lol

Impedance and gain are how to “match” a preamp To an amp. Vital stuff. Your statement is like saying that a Woo Audio WA7 is just as good as something with a lot of power with a Susvara because they are both headphone amps Which obviously is a silly statement. Matching is always important and saying a preamp doesn’t need to be matched to an amp is equally silly.

 

[gregorio]

Your statement is like saying that a Woo Audio WA7 is just as good as something with a lot of power with a Susvara because they are both headphone amps Which obviously is a silly statement.

Oh dear, who’s “misinformed” and making a “silly statement” now? A Susvara is a set of headphones, not an amp! lol. Of course you have to match the amp output to the transducer input because transducers vary hugely, there is no “line level” for transducers. You don’t seem to know what “line level” is, why it exists or why DACs and amps are compliant with it. This is especially funny as you stated “it is important to know what your are doing with gain …”! lol

G

 

[Rattle]

Unless you do not like the way your amp and DAC sound together there is absolutely no reason for a pre amp unless you want to hook up more than one DAC to an amp etc. It will always change the sound. There's no reason for it unless you are looking to change/color/tilt the sound of your DAC and amp. If that's the case you chose the wrong gear to begin with.