How to judge a preamp's sound

hilde

i would say that most high end preamps/linestages do have a distinctive tonality / ’sound’ that can be consistently heard -- even in driving a variety of amps

this can be in terms of tonality, drive/prat, grain/pixel size so to speak, size and depth of image, clarity/precision of imaging or lack thereof

of course there can be notable exceptions (e.g., signfiicant impedance mismatch, cabling complications...) but by and large, in my experience, this is true

 A reviewer usually uses equipment they are familiar with, not just throwing random gear into a review. 

you can hear tendencies in preamps that carry accross different power amplifiers much in the same way different phono preamps can sound  distinctive despite different turntables, cartridges and amplifiers. 
synergy matching is very important to optimize the overall sound.  

hilde45
How to judge a preamp’s sound

The ultimate preamp shouldn’t have a sound, it should sound like nothing eg. a piece of wire, like going direct from source to poweramp.

Now if you have a source that needs a bandaid fix, by coloring with some sort of distortion, then there are many preamps that can do this, but finding the right one is a big ask.

Wouldn’t it be better and far cheaper to change the source to one you like, and then go direct with it to the poweramp for the ultimate in transparency and dynamics and lowest possible distortion/coloration?.

Cheers George

Thanks for the informed replies. They make sense. (And @russ69 I didn't get the sense they were throwing in amps at random.)

I have read so many posts where people discuss the major differences between amps that I figured it would be hard to estimate the character of the preamp across those differences. I imagined someone trying to describe the flavor of a bland meat in, say, a curry, a tomato sauce, a hollandaise, etc. But this analogy appears to be a bad one. Glad to know better.

It's easier to characterize the sound of 1 component if you can try it with many other components.  You will eventually hear a consistent trend.

My question is, Can someone accurately generalize about "the" sound of preamp across a variety of different amps? Wouldn’t the amps be enough of a variable to at least complicate the "character" of a preamp?

Yeah, I’d agree with that. While it’s certainly interesting to hear how a pre might pair with a given amp, if you’re interested in the relative sound of a preamp the logical, direct, and more common reviewer methodology would be to compare it to other preamps. Duh.

Hmm. So now we have the claim that:

(a) to hear what a preamp sounds like, try it with many amps and see what qualities persist through the changes.

vs.

(b) to hear what a preamp sounds like, keep the amp the same and then change between preamps to listen for the changes between preamps.

I suppose these are not necessarily at odds, though. They could be complementary?

Another option might also include

(c) Keep the preamp and amp the same, and change the tubes in the preamp only. See what qualities persist through tube changes.

I'd guess that (c) offers the least information, but it would offer some, no?

Let’s just call it a complex affair that can reach self interpreted conclusions via many different paths.

And if one had a textbook to explain it all, then it would say much the same, with some routing possibilities given in the text, for reference. Where the one attempting to apply the text is told to have a go at it.

Like driving a car. A thing, or act..which is an in-situ continual correction - that is meandering forward.

If one is trying to set such in stone, that would be fruitless, as it is not universally applicable by any measure.

Everything affects everything so there is no hard set conditionals in any of it.  And, if one makes it to the set conditionals, somehow, the whole thing is individually in parts and in the connected self altering whole (as a unified chain), then we deal with individualism and individual interpretations. 

There most definitely is a lot of hard scientific and engineering and measurement data in all of it, but the self created nature of human hearing as individuals, and the breadth of the variables in hardware and humans... ends up reducing it all to a wine tasting experience.

@teo_audio

Let’s just call it a complex affair that can reach self interpreted conclusions via many different paths.

Everything affects everything so there is no hard set conditionals in any of it.

My limited purpose was to raise for scrutiny a practice -- one metric or method -- which seemed to me to be inherently flawed. I'm no longer sure I was right, given some of the comments above, which are helping me reconsider.

I’m not sure what you mean by "self interpreted conclusions" or "no hard set conditionals."

What seems clear from what people attest to in forums, reviews, and in their living rooms is that some judgments can be made with some level of confidence, despite the multi-variable, relational, and dynamic nature of the phenomena we’re experiencing. Same thing is true with food, wine, relationships...well, everything. We’re in a Heraclitean universe (no stepping into the same river twice) and yet fire burns, sugar is sweet, and metal dome tweeters can be harsh, sometimes.

If the preamp looks really sharp it will sound fine.

@hilde45 FWIW even a cable and no preamp at all has a sound unless you jump through some hoops to prevent it doing so.


It helps to have recordings with which you are familiar. I use recordings I made myself (and have the master tapes) so I know how they are supposed to sound. But that is a luxury most people don't have, so start with recordings you've heard many times and then see how changing out a component seems to affect the sound of that recording. In a nutshell, that's how reviewers do it. This is entirely subjective so you won't get 100% consistent results. So a consensus of more ears is also helpful.

@atmasphere Thanks. Those are good suggestions. I imagine keeping the cables the same would be advised in any comparison.

I'm not presently involved in trying out preamps, but I still listen to reviews for fun. I thought I had spotted incorrect advice and was seeking to learn if that was true. 

The idea that a preamp should not have a sound is over simplifying its role.  
Ideally it should not add or subtract from the tonal spectrum and balance of the source but this is not realistic.  Preamps can be evaluated on their tonal presentation and balance and how well the do at the frequency extremes and how transparent and clean sounding it is.  
Also it should not add any additional noise or distortion but again this is not realistic. 
Finally the amplification withing the preamp can be evaluated on its representation of drive and dynamic energy.  For me a preamp should offer exceptional micro and macro dynamic energy.  
Bottom line- a preamp can easily be evaluated on its sound quality when compared against others.  Saying it should have no sound is a gross over simplification and not possible.  

If you’re trying to decide on a sports car, do you drive one car on a bunch of different roads to decide which one you like or would you compare several cars on the same roads? Sure, in the first case you’ll get a good idea of what that one car can do, but it’s not as helpful in providing a relative perspective and/or making a buying decision. And after all, isn’t that the most important information a review can provide to a reader? Reviewing one preamp with a bunch of amps is interesting and somewhat helpful, but IMHO it’s less effective than comparing one or more preamps to each other. Humans are inherently poor at judging things on an absolute basis and much better at judging relative performance. Every reviewer has had the experience of thinking they have the sound of a component nailed, then they substitute in a competitive product and they realize how off they actually were in their initial impressions. Without a comparison they’d have been way off in their assessment. This is why I always take reviews written without a comparison example with a HUGE grain of salt. Anyway, just my take on it.

The idea that a preamp should not have a sound is over simplifying its role.

No not really, they are a left over piece of equipment from the dinosaur days of vinyl, when there was only "millivolts" of output from cartridges,
today there are "volts"!!! all that's needed IF you have a few sources is a quality source switch box like this https://goldpt.com/sw4.html

And also back then in those vinyl days it was a long held saying as well, "the best sounding preamp should sound like a piece of wire" or "sound like no preamp"

Cheers George 

i think we are making this too hard

to figure out how one new piece of equipment sounds, just insert it into a ’reference’ system that the owner knows very very well and hear the SQ delta (if any), substituting for the reference unit ...

in this case, discussing a preamp, insert pre X in place of reference pre A (and reference pre A may indeed be no preamp at all)

then, to confirm, if you want to be more sure, try against a second reference pre B... if you wonder if there is pre to power amp matching issue, try a second reference power amp

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speaking in ideals or in theory is just that... in the real world everything has an impact on the sound

and we also don’t know what the signal actually sounds like, since there are various equipment and transducers capturing, processing and reproducing, none of which are ’ideal’, and most far from it

And also back then in those vinyl days it was a long held saying as well, "the best sounding preamp should sound like a piece of wire" or "sound like no preamp"

These two, 'sounding like a piece of wire' and sounding 'like no preamp' are not the same. The latter is good, the former is really variable!

I've always been intrigued by "sound(ing) like a piece of wire." Do we have wire listeners???

back then in those vinyl days it was a long held saying as well, "the best sounding preamp should sound like a piece of wire"

These two, 'sounding like a piece of wire' and sounding 'like no preamp' are not the same. The latter is good, the former is really variable!

I’ve always been intrigued by "sound(ing) like a piece of wire." Do we have wire listeners???

If anyone questions the implication of this classic statement that goes back to gramophone days, then sorry, there is no hope, "get out of the game" another saying, just in case😉

What is the sound of a "piece of wire"?

Depends. Which wire are we talking about- and in which direction?

... and how much you paid for it  ...  LOL

...and remember, soup isn’t a meal unless there are chunks in it.