What is responsible for soundstage in a preamp design?

[k brown]

One thing that hasn't been brought up yet (unless I missed it), especially in the context of stereo pair mic'ing, that can have a clear effect on the dimensional realism of the sound, is stereo seperation (crosstalk) in stereo circuits. This would have less to do with topology or devices used, and more the circuit implimentaion. layout and grounding, in pres with two or more channels in a chassis.

 

[Lampie519]

Really, that is your evidence?

No, not evidence just in some cases i have had similar experiences as shown, that's all.
If we look for a scientific answer as i do we should not dismiss all we don't want to understand and keep an open mind even if it appears Illogical at first.

 

[user 37518]

No, not evidence just in some cases i have had similar experiences as shown, that's all.
If we look for a scientific answer as i do we should not dismiss all we don't want to understand and keep an open mind even if it appears Illogical at first.

Again, more experiences. You say it is so, because you've experienced it and you expect us to accept already debunked arguments like TIM, just because you think so, without any evidence other than the Snake YouTube guy, your opinion and experiences..

 

[Cranehazard]

I see nothing wrong with the INA217 or the fact that it is used in interface mic preamps. We don't even know what the original poster means, so we can't assume that it is due to parts like the INA217.

I'm not topology shaming. And I know what he means. He was comparing stand alone mic pres to interface pres and this is my interpretation of why they sound different.

 

[Lampie519]

You don't need to take my word for it but a true scientist will do his own experiments and not just trust what is said , debunked or not.... how many time have existing theories been proven wrong... maybe so for TIM, that is where we stand now, who knows what we think true next year...
There is no progress if we don't challenge the known (accepted) theories.

In case a change can be heard by reversing cables it is not something i can explain (nor can any single individual with limited resources).
And if you can't hear any differences you should consider yourself lucky (no pun intended).

 

[Matt Syson]

A bit late to this thread but I like a good 'bun fight'. Speaker wiring: for all the many studios I have been to the range of cables used is interesting where people have tried to cram 6mm CSA wires into the binding posts for NS10's to 1mm 'zip cord type for BIG monitors and everything in between.
As this is a 'preamp' discussion we can discount that. I noticed 'instrumentation' amplifier being referred to a while back, but this mainly refers to a 'differential' type input commonly needed to retrieve signals from very hostile industrial or medical environments so good CMMR is essential at least over the expected signal bandwidth.
OP amps are credited with a 'military' origin where they were a 'building block' for analogue computers for 'gun aiming' so the function and performance of any given circuit SHOULD be determined by the components placed around the (theoretically perfect) Op amp for which massive strides have been made since the early days of course. The awkwardness of asymmetrical power supply rails from the first valve op amps (Philbrick?) carried onto the transistor 709? with it's plus 12 and minus 6 Volt rails. Going back to 'spoof' and misinformation I would like to see the advert (possibly April 1st edition) of dB magazine from early 1970's where a particular loudspeaker on offer with DC to MHz frequency range gets heavier when you take it out of it's shipping crate among other interesting properties.
Of course damping of particularly dynamic mics was one of the things Mr Rupert Neve made reference to in his later designs where high input impedance would allow greater voltage output from a given mic rather than the best POWER transfer by using a transformer in search of the best signal to noise ratio.
I had a discussion with Mr Sowter many years ago over the design of a transformer I was interested in and it was observed that steel and Mumetal affect various parts of the audio spectrum differently so you have to decide the operating level (flux density) as well as intended frequency and distortion characteristics you would like. Jensen concentrated on making their transformers as transparent as possible over a wide bandwidth.
K Brown's comments are of course valid in that the handling of signals deemed to be a 'stereo pair' is important as the exact nature of crosstalk between left and right can have interesting effects. crosstalk is often 'capacitive' in nature so typically rises with increasing frequency. then it may depend on whether the 'hostile' path is in or out pf phase with the ''receiving' path and indeed if it is in a preamp/EQ unit it could be occurring part way through the EQ section thus either adding or subtracting or even part of a 'comb filter' sort of effect where sloppy layout could reverse the effect at other parts of the signal path.

 

[abbey road d enfer]

One thing that hasn't been brought up yet (unless I missed it), especially in the context of stereo pair mic'ing, that can have a clear effect on the dimensional realism of the sound, is stereo seperation (crosstalk) in stereo circuits.

I would think it has not been considered because the subject was of the 3-dimension-ness of a single mic preamp.
Indeed, when signal is captured/transmitted in multi-channel mode, the notion of "space-rendering" makes more sense.

 

[Tubetec]

Lets say we have a mono sound source , reproduced on the left ear of a set of headphones , no matter how good the crosstalk performance of the electronics ,theres always going to be a certain amount of crosstalk going on between our ears , ie inside our skull.
Like wise if we produce a mono sound on the left speaker , our right ear is going to pick up more or less the same signal , with some time of arrival difference and a little loss in the HF range , that allows us pin point the direction of sounds .
What Im saying is crosstalk is a fundamental part of how human hearing works .
An electrical signal displayed on a scope or FFT is without any of these real world interactions ,
the moment a sound is produced were into the realm of perception of sound , we all have different shaped heads ,ears ,nose etc
We can probably agree substantially on a electrical waveform displayed on a screen , the moment speakers, rooms and our ears are involved theres many more variables at play ,

In the real world sounds often contain transients , ie momentary peaks well above the average , your led based PPM often isnt going to be fast enough to display them .
Audio equipment with a gracefull overload characteristic pulls down these ugly spikes in program material and gives a higher average level than say a modern op amp based design , where we want to avoid clipping under any circumstances , this might be responsible for what people are describing as depth .

The ear and auditory system isnt linear despite what some might have you think , it also compresses distorts and intermodulates on the peaks , if the equipment is already producing short duration higher order distortion on the peaks it might account for a preference for the older tube or discrete transistor circuits with transformers . A series of circuits with a soft clipping characteristic ie preamp eq and compression with proper gain staging deals with these peaks very effectively , a modern op amp based design will either clip in an ugly manner or you reduce the signal level , in which case these short term peaks get through . We cant anticipate exactly what signal level is going to hit our preamps during a performance after all ,

 

[abbey road d enfer]

No one here is questioning the fact that different preamps sound different and some would prefer one to another. As well, no one is questioning the fact that possible distortions can modify the ratio of early reflections and the relative amplitude of transients (in particular, it is well known that applying an AllPassFilter that smears transients also decreases the peak factor).
What is questioned here is the abusive use of 3-D, because transients and early reflections are only 1.5D. Depth is a more correct word.

 

[user 37518]

In case a change can be heard by reversing cables it is not something i can explain (nor can any single individual with limited resources).
And if you can't hear any differences you should consider yourself lucky (no pun intended).

 

[abbey road d enfer]

I'm starting to think we are being trolled.

 

[Newmarket]

I'm starting to think we are being trolled.

Bit harsh I mean if I can turn my cobbled together home kit of A&H and Soundcraft Spirit desks and monitors running Reaper on an isolated XP system into a quantum computer by using some fancy cables then I'm definitely interested

 

[nielsk]

How's this for fuel on the fire... I argue that specs are meaningless, in making music recordings to sell to the general public all that matters is how the humans it is being marketed to respond to it. In general they could not care less about how it was recorded or what equipment was used.
The first time a person hears a recording is the "true" blind listening test, and is the predominate factor in the recording's commercial success.
The only situation where what is most important is how 1 mic into 1 pre-amp matters most is if you are making a mono live 1 mic recording (and there have been some incredible ones made, listen to the Louis Armstrong & Doris Day sessions for an excellent example), as soon as you add another sound source what matters is how they interact, and in my experience the set-ups that sound "best" when listened to in solo rarely sound best "in the mix". Interaction and inter-modulation distortion in the source (recorded track) and other sources such as other tracks and noises have a significant psycho-acoustic affect and change how humans respond when listening.
I have had the opportunity to use pre-amps made from the very beginning to present. They all sound different to me, and they all "fit in the mix" differently. Part of what makes a great engineer is how they deal with whatever equipment they have at hand and make a great sounding recording, and knowing what to do to make the production of the final product for it's intended market as easy as possible.
Having great sounding gear makes the job easier, having a great sounding source makes it not a job.
The predominate cases where I have preferred a very fast pre-amp with extended frequency response and high nickle content transformers is when recording all acoustic instrumental music live. Not so much for most everything else.
And yes, on various sources using various mics, different pre-amps have an impact on how "in your face" or "buried" a track in a mix sounds. There are many examples of lead vocals being extremely buried has been a part of the success of a recording!

 

[user 37518]

How's this for fuel on the fire... I argue that specs are meaningless, in making music recordings to sell to the general public all that matters is how the humans it is being marketed to respond to it. In general they could not care less about how it was recorded or what equipment was used.
The first time a person hears a recording is the "true" blind listening test, and is the predominate factor in the recording's commercial success.
The only situation where what is most important is how 1 mic into 1 pre-amp matters most is if you are making a mono live 1 mic recording (and there have been some incredible ones made, listen to the Louis Armstrong & Doris Day sessions for an excellent example), as soon as you add another sound source what matters is how they interact, and in my experience the set-ups that sound "best" when listened to in solo rarely sound best "in the mix". Interaction and inter-modulation distortion in the source (recorded track) and other sources such as other tracks and noises have a significant psycho-acoustic affect and change how humans respond when listening.
I have had the opportunity to use pre-amps made from the very beginning to present. They all sound different to me, and they all "fit in the mix" differently. Part of what makes a great engineer is how they deal with whatever equipment they have at hand and make a great sounding recording, and knowing what to do to make the production of the final product for it's intended market as easy as possible.
Having great sounding gear makes the job easier, having a great sounding source makes it not a job.
The predominate cases where I have preferred a very fast pre-amp with extended frequency response and high nickle content transformers is when recording all acoustic instrumental music live. Not so much for most everything else.
And yes, on various sources using various mics, different pre-amps have an impact on how "in your face" or "buried" a track in a mix sounds. There are many examples of lead vocals being extremely buried has been a part of the success of a recording!

I agree that, in the end, the music is what matters most, rather than whether it was recorded throught this or that pre. However, here, we are interested on making things as best as we can circuitry wise, in which case, specs do matter.

 

[user 37518]

No, not evidence just in some cases i have had similar experiences as shown, that's all.
If we look for a scientific answer as i do we should not dismiss all we don't want to understand and keep an open mind even if it appears Illogical at first.

I just realized that the video of the guy you referenced claims that a DIGITAL FIREWIRE cable makes a SOUND difference if you reverse the direction, he also promotes cable risers make a sound difference, yeap, rising the cable a few inches makes a sound difference according to him, the best part was when he said white noise is bad to test frequency response because you ears can't distinguish anything, what is the evidence he provides? the same you provided Lampie519: HE HEARD IT, and you can't say otherwise. I was going to ask you if you support these views, but, at this point I think there is no point to continue having this conversation with you.

It is true, sometimes you just need to let people talk and they will fully reveal themselves.

 

[user 37518]

I'm starting to think we are being trolled.

We are absolutely being trolled

 

[ashdot]

Actually, the structure of the INA217 is a textbook 3-opamp instrumentation amp, when the dedicated mic preamp chips are essentially a Cohen arrangement. Potential differences are slightly better distortion for INA217 and slightly better noise for SSM2019. Instrumentation amp has 4 input devices, when Cohen has only 2.
I don' t think the differences can be heard in normal use.

Please explain what is a Cohen arrangement.
I can’t find anything on the web.
Thanks!

 

[user 37518]

Please explain what is a Cohen arrangement.
I can’t find anything on the web.
Thanks!

Look for Double Balanced mic preamplifier. Cohen was the inventor

 

[Mr. Moscode]

And a single mic preamp can do that? (that's the original question)

I didn't say it could.

No harm, but confusion, which is not welcome in a scientific discussion.

I wouldn't elevate it to pure science. Perception is not a science. I think you may need a ladder to get off your horse.

Yes we do, but what does it imply in this discussion? Do you surmise that de-bunking myths is detracting from the search for good entertainment?

No. It's amazing how so off the topic this is from the original post. Not the first time.

If you mean adding a little make-up, it's what SE's do by choosing the right signal chain, adding EQ, FX and whatnot. There's no need for improper description. There's no lack of proper words for this.

I get that. That's the point. Again, just a metaphor.

As long as the electrical properties are identical and the contacts are good, I don't see why not. But I wouldn't use a zip cord for loudspeakers (cause too small gauge) or for mics (cause not shielded).
There has never been any proof that OFE (Oxygen-Free-Copper) has significantly better electrical performance than standard ETP (electrolytic-tough-pitch). The 1% difference in conductivity is irrelevant in view of the large possible variations in length of cables.
Being oxygen-free does not necessarily make a cable suitable for a job.

Thank you for your opinion. I would beg to differ but I don't have the time.

 

[Mr. Moscode]

No one here is questioning the fact that different preamps sound different and some would prefer one to another. As well, no one is questioning the fact that possible distortions can modify the ratio of early reflections and the relative amplitude of transients (in particular, it is well known that applying an AllPassFilter that smears transients also decreases the peak factor).
What is questioned here is the abusive use of 3-D, because transients and early reflections are only 1.5D. Depth is a more correct word.

And cables don't?

 

[Mr. Moscode]

Part of what makes a great engineer is how they deal with whatever equipment they have at hand and make a great sounding recording, and knowing what to do to make the production of the final product for it's intended market as easy as possible.

It's intended market makes all the difference in the world. Art versus commercial success may have nothing to do with great recording gear or everything to do with it.