[upstateguy]

I wanted to spin this off from the All DACs Sound the Same thread because I'm having a hard time justifying this in my mind.
 
In order for complex devices like DACs and Amps to sound the same, the components that make them up must also sound the same.
 
 
So :
 

1. Do all opamps sound the same? 
2. Do all transistors sound the same?
3. Do opamps sound like transistors and vice versa?

1. Does a Hybrid mosfet/opamp dac/amp sound like a mosfet dac/amp or an opamp dac/amp or do all three sound exactly the same?

1. Do capacitors have a sound signature?

1. Do all resistors sound the same?  What about plugs, jacks, switches and volume pots?  Do they all sound the same, regardless of manufacturer?

1. Do premium parts sound different from el cheapo parts, or do all parts sound the same?

1. Can power supplies affect the sound?  Will a dac/amp fed from a switching PS sound the same as one fed from a linear PS? 
2. Does the transformer quality matter?  Do all transformers sound the same?

1. Do all dacs or amps filter power in the same way?  Is clean power important? 
2. Does all casework and shielding sound the same?
3. What about the boards the components are soldered to?  Are some boards better than others?  What about the layout on the board?  Will that affect the sound?

 
 
 The more I look at it, the more it seems impossible for things to sound the same.  Some things may sound similar, but there are too many variables for everything to sound the same.   What do you guys think?
 
USG

 

[Grahame]

Consider the following.
 
Consider two systems made of differing components. If the components sound different how can the systems sound the same?
 
What do we mean by sound the same?  Produce the same output for the same input?
 
Why not measure the the outputs for the given systems, and "diff" them. i.e.  measure the difference.
 
If the absolute difference is zero, they are the same. If the difference is below the threshold of audibility, then they will sound the same to all intents and purposes.
 
There already exists software to do just this. It is called Audio Diff Maker and is described here: http://www.libinst.com/Audio%20DiffMaker.htm
 
Given the same input to two DACS you could see if they sound the same, or if not get a measurement of the difference.
 
In this way you could quantify the difference.
 
The approach of minimizing differences to below audibility was used by Bob Carver to make "two amps sound the same" in "The Carver Challenge" 
 
Described in this PDF file http://carvermk2.com/Docs/Carver%20Stereophile%20Challenge.pdf
 
If the goal of an amplifier is to be "a straight wire with gain" , then any two correctly implemented amplifiers that meet this spec ( and are used within their operating limits  ) should  sound the same - i.e. have no "sound" of their own. How they interact with real world transducers is another matter, but you could argue the point that if they are unduly influenced by the load they drive, then they are poorly designed / implemented - a good design / implementation would not exhibit these flaws.
 
In the same way, A DAC is just a mapping function mapping it's (digital) input to (analog) output.
 
Any DAC that maps correctly should match any other DAC that maps correctly. A DAC that does not map correctly is broken by definition.
 
(Note: this ignores the design and implementation of the analog output section used to take the DAC (chip) output to line level )
 
 
 

 

[upstateguy]

Quote:

Consider the following.
 
<snip>  
 

Hi Grahame
 
I'm quite familiar with the DiffMaker and the Carver Challenge as well as most of the classical "can't tell the difference" evidence that's been accumulated over the past 40 or so years.
 
I really hate making claims because if you do, you can be asked to provide data to support it.  So in the "all dacs sound the same" thread, I could have trotted out the diffMaker and asked for some recordings to substantiate the claim that all dacs sound the same.  But that's not the point. 
 
In that thread I posted about some things that didn't sound the same (to me) and it made me think that maybe some of the things we  automatically think sound the same, actually do not, because the components they're made from don't sound the same. 
 
In one example, a dac with an on board usb implementation using a 2707 chip doesn't sound nearly as good as coax from an external transport using the same chip.  It's not day and night but it's past the JND and audible enough to develop a preference for one over the other.
 
Using your example of two amplifiers that are supposed to be "correctly implemented" (what ever that might mean), suppose one of them uses a cheap switching power supply and the other a linear PS?  Are they going to sound the same?  What if one is opamp based and the other transistor based?  What if they have different topologies and shielding?  Suppose one is more sensitive to RF than the other?  Will they still sound the same?  I don't know.
 
So what's your take on it?  Do you think there's any sonic difference between the components that might make similar devices sound different?
 
USG
 
 
 
 
 
 

 

[Grahame]

The beauty of the scientific method, and evidence based reasoning is that my opinion makes no difference. If different components do have a sonic difference, 
then independent observers should be able to reliably reproduce those differences, to a statistically significant degree.
 
If the assertion is that component A and B sound different, then it can easily be tested, by measuring a system using component A, then replacing component A with component B , and re-measuring , and checking the differences (if any). How hard is that? And we learn something in the process.

 

[tvrboy]

Everybody interested in this argument should read this article:
 
http://sound.westhost.com/amp-sound.htm
 
It's about why amplifiers may sound different from each other, and possible ways to measure that.
 
Under a very easy load, many amplifiers do indeed sound the same. But quite a few headphones and speakers present widely varying impedance curves. Others have very high voltage or current requirements, such as electrostatic or planar headphones. I think the "all amps sound the same" argument is an overreaction to those audiophiles who claim to hear extremely wild differences between amplifiers and personify their electronics (for an example of this, read any issue of TAS or Stereophile, or 6moons, or... any audio publication). While these descriptions are the product of a dubious "reviewer's" imagination and the totally unscientific test procedure, there are real differences in how amplifiers perform with different loads. If we all used one speaker or one headphone, then yeah, all well-designed amps would sound the same. But each transducer has very different power requirements.
 
I would like to hear from people who actually design amplifiers, such as Kevin Gilmore, Jason Moffat, or Pete Millet. Their opinions would add a lot to this discussion.

 

[Willakan]

Okay, there are measurable differences in transistors, opamps - circuit design can affect things, the length of hookup wire can affect things - there are tonnes of factors. But the thing is, modern equipment is, as a rule, well designed. Regardless of the approach the designer took, in the end if all the numbers are well below the threshold of audibility, there is no reason to suspect that having the numbers in a different position below the threshold of audibility would do anything.
 
Not everything "sounds the same", but if it is well designed it will. If I use an awful quality power supply consisting of the cheapest regulator I can find, there might be audible differences. But that's not good design. If I use a weird circuit topology that results in a stupidly high output impedance in an amp, there might be audible differences. But that's not good design.
 
Things do measure differently, but the differences between one good component and another are generally small. Additionally, when the base design is well thought through, it becomes less reliant on extraordinarily expensive and esoteric components. Opamps and transistors are just tools. It is the designer's job to choose and utilise his tools appropriately. If he has done his job, any differences should be well below the threshold of audibility.
 
PS: "Correctly Implemented" probably means here that all the relevant measurements declare that distortion, frequency response and time based error (and channel imbalance) are all far below audible levels. If one DAC that achieves this uses a switching PSU, another a linear PSU, why would it matter? They have both achieved the same goal. Certainly, the designer using the linear PSU may have had an easier time of it making such a well-measuring piece of kit, but in the end, they have both done the same thing.
 
EDIT: @ tvrboy: Hence the additional statement that: All amplifiers designed to alter the sound as little as possible, operated within the operating constraints within which they were designed to operate, will sound the same.
The problems looked at in that article are easily addressed with good design.
 
 

 

[Prog Rock Man]

Quote:

Originally Posted by tvrboy /img/forum/go_quote.gif

.....
 
I would like to hear from people who actually design amplifiers, such as Kevin Gilmore, Jason Moffat, or Pete Millet. Their opinions would add a lot to this discussion.

It would, but bear in mind they also sell amplifiers. So it is unlikely they will support the 'all well made amps will sound the same' argument. It is in their interests to say amps sound different and their one is better.

 

[Prog Rock Man]

Upstateguy, the do they sound different question will just lead to the usual circular debate. The real question is why do some people hear differences that others do not and can that be correlated to how a DAC/amp or whatever is made?
 
 

 

[Albedo]

Heraclitus: "You cannot step twice into the same stream". This is to some extent true, as the same equipment do not always sound the same as my attention alters, the question is how much do I pay for audio bliss?
 
In that other thread nick_charles mentioned Marantz CD5004, a CD-player with linear PSU, good jitter rejection and a symmetrical discrete analogue output stage. There's even paid attention to heat and grounding, so DIY this player seems a waste of effort as the price is $350. In the Stereophile test they did of course compare it (sighted) with a more exclusive player, but when they described the difference the all so usual words came up: delicate, subtle, relaxed, more holographic, more natural and in the end Marantz was to mechanical and splatty.
 
The point that I'm trying to make is the shift from mid-fi to the ooh.. so elusive high-fi, where ones paying through the nose for miniscule differences. Twenty one benajmins.. in reality one can wonder if it's as much about pride of ownership as it is about performance. Here is where the fun starts... one siding with the snobs, the others with DBT-testing.
 
Perhaps everyone these days can reach audio nirvana, if this is bad or not.. well, that's maybe what the whole fuzz is about?

 

[tvrboy]

Quote:

Upstateguy, the do they sound different question will just lead to the usual circular debate. The real question is why do some people hear differences that others do not and can that be correlated to how a DAC/amp or whatever is made?
 
 

Read the article I linked, that gives some very good possible answers to your question. Of course, I do agree that most "differences" people hear are either 
 
1. Placebo
2. Wishful thinking
3. Change in seating position (comb filtering effects)
4. Not level matching
 
Again, I agree that all amps designed for the same purpose will sound the same, excluding tube amps. But you have to keep in mind the amp designer doesn't know what kind of speakers/headphones will be connected, so compromises have to be made.
 
Oh yeah and it's Jason Stoddard, not Moffet! Oops!

 

[Prog Rock Man]

I did scan it and have read it in the past, but it is worth another read.
 
My amp is a hybrid tube and solid state. Where does that fit into 'all amps sound the same'?

 

[3602]

Here's a little side question that is still related to the amp components and its surrounding supporting element.
 
Among many Chinese audio communities, there is a claim of "audio tuning" in terms of amps and DACs. What this claim is, is that even if you are to take the schematic of a well-known amp (let's take the Grado RA1 as it is simple), even if you use the same parts, the same internal wiring and down to the same solder used, your "RA1 clone" will never sound the same (they did not say "as good") as an authentic RA1 "tuned" by Grado. Same goes for the popular beyerdynamic A1 clones, many "veteran audiophiles" claim that these clones have the same mechanical capabilities (best I can translate their term) as an authentic A1, but the musicality or the "emotions" if you will, is either "incorrect" or just plain "missing".
 
So I guess my question boils down to this. How, if this is indeed real, do you tune a solid-state device?

 

[Prog Rock Man]

That sounds like it is caused by the power of the Grado name! Seriously, is name and image really not an influence on sound?

 

[Yoga Flame]

 
Quote:

Here's a little side question that is still related to the amp components and its surrounding supporting element.
 
Among many Chinese audio communities, there is a claim of "audio tuning" in terms of amps and DACs. What this claim is, is that even if you are to take the schematic of a well-known amp (let's take the Grado RA1 as it is simple), even if you use the same parts, the same internal wiring and down to the same solder used, your "RA1 clone" will never sound the same (they did not say "as good") as an authentic RA1 "tuned" by Grado. Same goes for the popular beyerdynamic A1 clones, many "veteran audiophiles" claim that these clones have the same mechanical capabilities (best I can translate their term) as an authentic A1, but the musicality or the "emotions" if you will, is either "incorrect" or just plain "missing".
 
So I guess my question boils down to this. How, if this is indeed real, do you tune a solid-state device?

Quite possibly a case of cheap clones with fake parts inside. I've seen fake opamps, fake capacitors, fake ALPS pots, and so on floating around on eBay.
 

 

[Shike]

 
Quote:

 
My amp is a hybrid tube and solid state. Where does that fit into 'all amps sound the same'?

Quite well actually.  Tubes as an input stage act primarily as low distortion voltage devices for the output stage.  The output stage is traditionally a MOSFET or similar with very low output impedance.  This means the design is:
 
Low distortion
Low output impedance
Usually flat in regards to FR
 
For all intents and purposes, it's like using a IC or transistors in the input stage -- except you have a disadvantage of potential for microphonics too . . .
 
 
I also want to make a note regarding tubes.  A tube system that uses a good output transformer and tubes that still measure within a reasonable spec can very easily be inaudible in a DBT.  OTL designs are the ones that tend to have the most variance since the damping factor can widely vary based on what headphones you use which leads to FR deviation.  We could also debate if their distortion levels are high enough to be audible, which is the case in some and not others.  For example, a low THD OTL shouldn't impact a mostly resistive design in spite of what some here say (how many recommend using tubes with K701 for example?)