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Virtual preamps

Jose Hidalgo

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Hi everybody, I hope this is the correct place for this topic. If not, sorry! o_O

This may surprise some of you, as it goes against the "fidelity" part of "hi-fi". :oops: And yet I find it an interesting topic.
Let's assume we have already a good hi-fi system. Everything works fine, sound is very good, etc.
Source has to be a PC BTW.
What if from time to time we wanted to feel the "warmth" of a good old tube amp? What if we wanted to hear those nice even harmonics that we all like? What if we wanted an "analogue" feel? What if we just wanted to change the sound, ever so slightly, for some particular songs?

Rather than investing in a whole new hi-fi amp/preamp, we can use the source PC to accurately simulate such devices.
There are virtual preamp simulators that we can use to tweak the sound to our liking. Most are in VST form I guess, some may even be standalone apps.
The idea is to insert such virtual preamp in the audio chain, between the player and the output. So we'd have :
Audio player --> Virtual preamp --> Output (DAC, etc.)

The purpose of this topic would be to share our experiences with such virtual preamps (free and commercial), and to list the best of them for a hi-f... damn it, for pleasing our ears, lol. BTW, this is about altering the sound signature (in a tasteful way), so it's not about EQs, that's another topic.

I'll start with three freebies, in alphabetical order :
Any opinions / reviews / links welcome. Put your thoughts in the comments, and of course if you don't like the idea of this topic, you are also welcome to browse another one :p Thanks everybody!
 

Kal Rubinson

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I don't mind the idea of the topic and a discussion. OTOH, actually doing something like this is anathema to me.
 

LTig

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If it improves the sound of a bad recording - why not. As long as no one claims transparency, of course. Certainly cheaper than an expensive boutique amp with a "house" sound.
 
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Jose Hidalgo

Jose Hidalgo

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If it improves the sound of a bad recording - why not. As long as no one claims transparency, of course. Certainly cheaper than an expensive boutique amp with a "house" sound.
That's exactly my point. :) I know it may sound heretic to some, but we all have some bad recordings that we still love, and we wish there was a way to make them better, at least to our ears. The purpose here is to use the virtual preamp only occasionally, as an alternative to the main listening method for some specific recordings.

With that said, there are lots of virtual preamps, some bad, some good, at least for our purpose here which is listening (not mixing/mastering). So the aim of this topic should be to list those who are suitable for our purpose, while at the same time putting aside those who may be suitable for other purposes but not for ours. I hope that makes sense.
 

mnemonix

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What might be interesting (since this is ASR) would be some measurements, of the kind Amir uses for hardware, to accompany the subjective impressions, so we actually know in what way and to what degree these plugins are changing the sound characteristics and don't just end up back in the world of "more emotional" and "massively improved soundstage" mysticism. We might even learn something about the audio characteristics that lead us to these descriptors or enable more informed choices about how we choose to interfere with an otherwise neutral sound.
 
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Mnyb

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The monumental stupidity of high end pre-amps comes to play here ? No tone controls no balance no mono button , no loudness, no impedance and gain adjustment on phono no rumble filter . a very good control is a tilt control as Quad did them (and Meridian has in digital form , thats how their "treble" works ) .
Tilt control , you slope the whole frequency range up and down , this help a lot for listening distance to speakers ? anu one noticed that speakers are brigther close up in small rooms ? Manufacturer has to assume some listening distance .

When i moved , my speakers sounded a bit to forward (as i sit closer )and i have to use another setting for tilt control where i live now. The acosutics is actually better so overall it sounds better . but the "harshness problem" would have forced me to change speakers if i had a "normal" audiphile preamp .
I think reviewers should stop testing preamps until normal functionality is restored :rolleyes:.

A modern take would be to do this in digital form and combine DAC and preamp obviusly for an outboard solution , including rom correction and sub xover .

As a virtual preamp :

Do any of the popular software players has any usefull tone controlls mono etc ? Many have a plug in system , but a nice UI with casual controlls like an equalizer and toine controls .
The virtual preamp could be a nice UI to a software player , heck it could be an actual preamp if you include some audio interface with analog inputs , and source switching in the UI ?
 

Wombat

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"Bad recordings" need specific individual attention to address issues.

I can't see that random, 'tinted', preamps are a fix.
frown.gif
 
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Mnyb

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"Bad recordings" need specific individual attention to address issues.

I can't see that random, 'tinted', preamps are a fix.

Yes i like the idea of virtual preamp , but not as a just as distorsion generators , but other creative ways to change the sound . for example lessen the channel separation (for gimmick stereo records from the 60's) or widen the stereo image . de-emphasis and HDCD and Dolby-A correction ?
You can develop the concept further it could ofcourse include filters for added "warmth" or "clarity" but these can be purpose designed and much better than emulating some random tube amp . And of course room correction and eq tone controlls balance etc .

The software could even remeber settings for certain songs ?
 

Blumlein 88

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People who record music want to do all sorts of things to it.

My Antelope Audio device has DSP to mimic to a high degree of fidelity dozens ofl actual hardware devices that were common in studios in the past. It seems to work pretty well. I myself have not used them. Just played with them some to see if they work.

People still are cultish about tube amps, and pres, and triodes and tape and LP etc. etc. If you can fake it in software why not. I think the gear itself and all that goes with it finding the matching other gear for all to work are what make it a satisfying path for enjoying music. So I don't think selecting the same exact sound on a list of DSP features is going to be the same experience even if you get the same sound.
 

Blumlein 88

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Yes i like the idea of virtual preamp , but not as a just as distorsion generators , but other creative ways to change the sound . for example lessen the channel separation (for gimmick stereo records from the 60's) or widen the stereo image . de-emphasis and HDCD and Dolby-A correction ?
You can develop the concept further it could ofcourse include filters for added "warmth" or "clarity" but these can be purpose designed and much better than emulating some random tube amp . And of course room correction and eq tone controlls balance etc .

The software could even remeber settings for certain songs ?
All of that is already available even well beyond what you describe. It mostly exists for the recording side, and most audiophiles don't know about it.
 

Mnyb

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All of that is already available even well beyond what you describe. It mostly exists for the recording side, and most audiophiles don't know about it.

yes it does , I was thinking of "consumer packaging" :) almost everything is done already , the trick is to make it user friendly and marketable , some knobs for the end users to twiddle .
I Think you can get a consumer cult around that too, resampling and digital filtering in the computer before sending it to the DAC's comes to mind endless (imo uneccessary ) tweaking for those inclined to do such things .
You can probly create a story and guru around a plugin too .
 
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Jose Hidalgo

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What might be interesting (since this is ASR) would be some measurements, of the kind Amir uses for hardware, to accompany the subjective impressions, so we actually know in what way and to what degree these plugins are changing the sound characteristics and don't just end up back in the world of "more emotional" and "massively improved soundstage" mysticism. We might even learn something about the audio characteristics that lead us to these descriptors or enable more informed choices about how we choose to interfere with an otherwise neutral sound.
Of course, I don't accept mysticism and I believe in measurements.
One thing that has been proven a long time ago is that even harmonics are flattering to the ear, and are a distinctive characteristic of tube amps. So increasing even harmonics may be one of the ways of "improving" the sound for some specific recordings, at the expense of more distorsion of course.
 

Mnyb

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Of course, I don't accept mysticism and I believe in measurements.
One thing that has been proven a long time ago is that even harmonics are flattering to the ear, and are a distinctive characteristic of tube amps. So increasing even harmonics may be one of the ways of "improving" the sound for some specific recordings, at the expense of more distorsion of course.

I think it's more complicated than that unfortunately , it's often repeated but the proven part i'm unsure of . Anecdotaly it does work for some recordings for sure :) .

But you cant have one without the other so the uggly IMD shows up again , the usual dirstorsion mechanism in equipment are such that the nonlinearity that creates THS also makes IMD (don't ask me abouth the math i'll run away .... )

So you can add warmth to the girl with guitar recording , but it will fail on some more complex music ?

So that it could be turned on and off as you please and use it for selected recordings could be usefull .

But could you make it better ? a plugin that only makes H2 and not even spray of harmonics up to infinity or frequncy dependent distorsion insertion ? or some other tailored settings just a couple of harmonics . Imo it tends to bunch up if everything distorts and we are back to "harsch recordings" again .
Example: experiment with adding distorsion just to the bass and you get more harmonics from the bass instruments in the lower midrange ?
The possibilities are truly endless, you could have a comunity around these filters
 

mnemonix

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I can't see that random, 'tinted', preamps are a fix. View attachment 81323

And yet, particularly in the digital domain, that is exactly the music creation process as self-styled music "producers" build VST fx chains comprising plugin numbers in double figures, many of which they don't understand, randomly tweaked whilst listening on a set of sub standard monitors in a poorly acoustically treated room.

Just one reason why, acoustic live recordings aside, I don't really believe there's any such thing as a true, neutral, unadulterated presentation of music; unless the car crash that took place in the producer's studio is really what you want.

Not that I disagree with your point!
 
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Jose Hidalgo

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@Mnyb this is a complex subject, because here in this topic the goal would be to please the ear (for some specific recordings) rather than having absolute "fidelity". We still don't know exactly how the ear works. Here are some examples:
  • Fletcher-Munson curves. They were later replaced by Robinson & Dadson curves, but then we realized that the latter were less accurate. Then they were replaced again by ISO 226-2003 standard, but then there is again a controversy around this standard (you can google it), which makes me still be more tempted by good old Fletcher-Munson. Anybody else feels this way?
  • The ear shape is so complex (and sometimes different from one individual to another) that it's almost impossible to take into account all possible resonances.
  • Not to mention that we don't all have the same earing abilities, just like we don't all have the same sight. That's why some people hear things that other people don't. And sadly that's also why some people take advantage of that by creating a lot of mysticism around audiophile stuff. That's why objective measures are so important.
@mnemonix : exactly! The albums that we buy (well, most of them) already have a LOT of VST FX treatment, so they are greatly adulterated vs. the raw performance. What we call "hi-fi" is nothing more than fidelity to THAT adulterated presentation of music. Most of the time we can't do anything about it. But sometimes, if some audio engineer did obviously a bad job and we have a means of "reverting" it at least in part, why not use it?

The same could be said of audio reparation software such as IZotpe RX, with their declicking/decrackling filters. Of course some people will love the original sound of old recordings with all the crackling. I sometimes do! But sometimes, only sometimes, I don't, and in that case I am tempted to use such filters and see if they improve the sound to my ears. And sometimes it does work. :)

Let me emphasize again that all this topic would make no sense if we didn't have a "good enough" hi-fi system from the beginning. We must first know what the "hi-fi" reproduction of a given "original" recording sounds like, before deciding to willingly modify it. And that includes system transparency, neutrality, but also the room. Everything must be "good enough" from the start (preferrably in a measurable way), or else we may be just fooling around with sound without knowing what we're doing.
 
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Blumlein 88

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Of course, I don't accept mysticism and I believe in measurements.
One thing that has been proven a long time ago is that even harmonics are flattering to the ear, and are a distinctive characteristic of tube amps. So increasing even harmonics may be one of the ways of "improving" the sound for some specific recordings, at the expense of more distorsion of course.
Do a search for pkane distort on the forum. Distort is software that member pkane wrote. You can add any kind and level of distortion you wish to a musical file and hear that result. Test out that ideas about H2 musicality or euphony. Software is free and excellent.
Okay here's the link. https://www.audiosciencereview.com/...t-audibility-of-distortions.10163/post-277173
 

RayDunzl

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makes me still be more tempted by good old Fletcher-Munson. Anybody else feels this way?

I use the 80 to 100dB level of Fletcher Munson for my theory of reproduction.

That's the flattest spot, the in the range of average to peaks when I'm listening attentively.

So, flat is my EQ.

And no other consciously added sweeteners.
 

Wombat

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Yes i like the idea of virtual preamp , but not as a just as distorsion generators , but other creative ways to change the sound . for example lessen the channel separation (for gimmick stereo records from the 60's) or widen the stereo image . de-emphasis and HDCD and Dolby-A correction ?
You can develop the concept further it could ofcourse include filters for added "warmth" or "clarity" but these can be purpose designed and much better than emulating some random tube amp . And of course room correction and eq tone controlls balance etc .

The software could even remeber settings for certain songs ?

I think you should read the OP, carefully, again.
 
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Jose Hidalgo

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@Blumlein 88 : Distort software seems brilliant! Too bad we can't just add it as a DSP/VST in the audio reproduction chain. I don't like the idea of feeding it one wav at a time.
 
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