Mic preamps with seemingly deep sound stage (depth of field)

Balijon said:

The point I am trying to make is not about noise floor, it is about relative accuracy to describe the wave-patern, which decreases when amplitude is lower.

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Please stop with the pseudo science "wave-patern" stuff. It's just completely wrong with no theoretical backing whatsoever.

This is again the same naive stair step view of digital signal, which completely forgets bandwidth and noise and how even the most simple conversion filters work (decimation or reconstruction filters). You absolutely need to study how digital signals are recorded and reconstructed before continuing your life as an audio engineer. I understand it's a difficult concept to grasp that what goes in and goes out of the converter do not actually correspond to the stair-stepped integer waveform of most audio editors in the world. Interpolation and decimation/reconstruction filters are a very complex topic and even though I've written commercial applications in this area, I still keep bumping to better algorithms and solutions so advanced it causes aneurysms.

Trying to nudge the thread back on topic, I've also found tube preamps with transformers seem to give best results in capturing depth and sound stage in recordings. And I mean a clean tube amp. The best ever soundstage I ever recorded got had a little less than 0.1THD% with a no feedback design using lundahl transformers. Still quite dirty compared to just about anything on solid state side.

Like abbey road d enfer was explaining earlier, I also suspect this is mostly to do with the distortion "shape" from tubes and perhaps the transformers.

I've even gone to great lengths trying to create digital models of some of these aspects. From experience I could generalize that mild distortions in low-to-mid bass combined with certain types of high frequency transient ringing can enhance a stereo image. But then, there are many types of distortions, IMD, cross-over, and plain harmonic distortions (or many forms of aliasing on digital side) for example and then it just fizzles down to individual tastes.

Kingston said:

Balijon said:

The point I am trying to make is not about noise floor, it is about relative accuracy to describe the wave-patern, which decreases when amplitude is lower.

Click to expand...

Please stop with the pseudo science "wave-patern" stuff. It's just completely wrong with no theoretical backing whatsoever.

This is again the same naive stair step view of digital signal, which completely forgets bandwidth and noise and how even the most simple conversion filters work (decimation or reconstruction filters). You absolutely need to study how digital signals are recorded and reconstructed before continuing your life as an audio engineer. I understand it's a difficult concept to grasp that what goes in and goes out of the converter do not actually correspond to the stair-stepped integer waveform of most audio editors in the world. Interpolation and decimation/reconstruction filters are a very complex topic and even though I've written commercial applications in this area, I still keep bumping to better algorithms and solutions so advanced it causes aneurysms.

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pff...  8) If you are such a specialist in this field, I am stunned by your lack of basic knowledge.
If I have the same analog wave-patern fed into a 24bit A/D converter:
One is resulting in 24-significant-bits to describe the wave-patern
One is resulting in 12-significant-bits to describe the wave-patern
which one would you choose as the most accurate representation?

Keep on the good work on reconstruction filters.

grT

amorris said:

Semi of topic, you guys would make a dub in reverse to correct the phase shift? Thats interesting. I will have to do some testing........

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I have never tried this, but I recall an open day at my University where there was a display about this.  The theory was given and it made sense.  When I get my open reel machine out of storage I will try it...

David

Balijon said:

If I have the same analog wave-patern fed into a 24bit A/D converter:
One is resulting in 24-significant-bits to describe the wave-patern
One is resulting in 12-significant-bits to describe the wave-patern
which one would you choose as the most accurate representation?

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What are you trying to prove? Repeats of this "wave-patern" combined with "pff.." just makes you look like a troll.

Your example is different from analog recording, how exactly? Yes, noise floor eats away input signal, but you seem to have this crazy idea that an analog signal with an equal noise floor to a digital signal is somehow better, as if you are able extract some magic juice from the analog noise floor.

Your reasoning for recording into digital format as loud as possible "to maximise the represented bits" is complete balooney. All you are doing is making sure to record the least amount of noise, just like you would in analog side.

Even the best 24-bit converters 4-8 LSB's (least significant bits) see pure white noise depending on how noisy your environment is.

[edit]

perhaps you should write to Waves about this new audio theory of yours. They have always been happy to jump on any new looney gearslutz fads, and perhaps they will again create a plugin to satisfy their most demanding customers.

For 3d-ness, I dig tube preamps with little or no negative feedback!

JW said:

Hmmmm.
Some interesting things. Thanks guys. I sort of half expected to hear "it's all about the room" in regards to this perceived depth discussion, which of course I know is true more than any one piece of gear, but which I can't change at this time. 

Anyway, just thinking of replacing my N72's with something different, like a prodigy pro project!

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Hmmmm, That's funny, I thought you had a friend with a great sounding warehouse sized room to record at? Oh, and that friend has an EZ1073 which he recently built for you to try and see if you like the "depth of field" or "sound stage depth". Also, I swear I heard someone say to me just a little while back: "Pre-amps don't matter".

Come try the EZ1073, there is no magic bullet, chase the dragon.

Balijon said:

pff...  8) If you are such a specialist in this field, I am stunned by your lack of basic knowledge.
If I have the same analog wave-patern fed into a 24bit A/D converter:
One is resulting in 24-significant-bits to describe the wave-patern
One is resulting in 12-significant-bits to describe the wave-patern
which one would you choose as the most accurate representation?

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You're not listening. You don't understand "significant bits."

If you use a 24-bit converter, the conversion result is always 24 bits, regardless of the instantaneous signal amplitude. That is the whole truth. The rest is commentary. Now go study it.

-a

I have just done a quick read thru the topic. Leaving digital & DAW's aside, I did not notice any mention of balanced or push pull preamp circuits

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I did mention push-pull (and single ended) on page one.

I have a single ended class A headphone amp designed by John Linsley Hood; I also built a push pull amp by the same designer. The latter have a sonic character that is fuller & punchier than the non push pull circuit, it just sounds better.

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Not saying it doesn't, but apart from that being a subjective or taste matter, it's only one example versus one example, of course.
Still, thanks for posting that experience. It is appreciated.
Perhaps Doug (emrr) will chime in.

So when we are talking about "depth of sound-stage" or "depth of field" WRT to how a pre-amp modifies/transforms/represents an impedance specific source signal to an impedance appropriate line level destination while modifying gain/power/mu. ie; 30r, 150r, 250r, 600r, 10k, ...

From a technical standpoint with interpretation-of-intent muddying the-waters-of-desire This to me relates to "audible-spectrum-or-range-of-focus" and perhaps the complex resonances/timbres/transients involved with the sound source.

The pre-amp either A:
Leans towards the "wider" depth-of-field where more things in the spectrum-range are "in-focus" yet perhaps slightly blurred or fuzzy...

Or leans more towards B:
A more "narrow" depth-of-field where the range-of-focus is narrowly imposed upon a more specific audible-spectrum which is sharply-focused and renders the surrounding-audible-spectrum more out-of-focus, blurred, or perhaps "fuzzy". And significantly so at both extremes.

I think I need a big-knob or something like a 26 pole greyhill switch.. which controls this parameter.. added to my next channel-strip project I am working up..

perhaps this switch could control a number of subtle-sounding-circuit-parameters while keeping the selected sensitivity/gain at a constant:
- Negative feedback... More or less...
- Zoebel values. A/B/C/D...
- SNR/Headroom...
- HF phase-lag-and-correction...

Cheers,
jb

co-pair, ortf or decca tree?

Im suprised no one mentioned the quality of converters in this argument.To me, they can be the difference between a small sound stage and a big one. Ive had a few converters ( behringer, alesis hd24xr, delta 44, rosetta 200) and found the best combo for a great sound stage was the rosetta 200 with a sebatron pre. I replaced the tube sin the sebatron with some siemens ecc801/s tubes, man that combo sounded so damn wide and deep. Made mixing so easy, but some might not like it because the mix lacked "glue".

And the clocking , even previously recorded material can sound better

Anyway, I'd love to hear other's opinions on projects here (or elsewhere) that fit your definition of preamps with a seemingly deep sound stage

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"hear" is the key word here.  Such a topic begs for sound clips so as to reach agreement on each's definition of "depth of xxxx".

lassoharp said:

Anyway, I'd love to hear other's opinions on projects here (or elsewhere) that fit your definition of preamps with a seemingly deep sound stage

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"hear" is the key word here.  Such a topic begs for sound clips so as to reach agreement on each's definition of "depth of xxxx".

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Agreed, If I had my studio up and running right now I would love to make samples and play with all of your ideas to help find a seemingly deep sound stage.

I just read through this thread and wanted to just say something regarding the comment on the Otari Radar II converters....
meh.... if you're making your judgement on digital converters based on 15 year old technology, id have to say that it's misguided.  People raved about that unit YEARS ago... they were head and shoulders above the rest at that time (IMO)... but not anymore.  Yeah they have a "sound" to them, but given whats in the market these days, I wouldn't use them anymore.
Take a test drive on a nice late model Apogee converter or the new black face avid converters, you'll be shocked when you compare it to even last years models.

While analog designs don't really change that much in technology, (ya got tubes, transistors, transformers, caps, and resistors etc etc),  digital is changing for the better (IN MY OPINION) every year.  The faster and more accurate clocks get, the closer to an "analog" sound you're gonna get.  Take a nice 192k session 24 or 32 bit float, and stack it up next to a nice analog recording, the only perceivable difference you're gonna hear (if you're not slamming the tape and just going for CLEAN reproduction) is the hiss on the tape. 

Regarding your perception of depth of field, i've always found that to be more about the MIX and where the engineer/producer decides to SEAT the instrument in the mix than anything.  You have your panning (L/R) and a balance between your dry and wet signal (if using room mics or a reverb unit) which will determine how "close" something will sound in relation to the 2 channels being given to the listener.  I believe early reflections are the key in that aspect.  If you get a chance to play with some crazy surround sound mixers and a good setup, this will be even more apparent.  (one reason some engineers will mix in surround and bounce to stereo)  Just my 2 cents, and im sure the analog purists will rip those pennies in half

PS I gotta give a HUGE hi-5 for abby for his post on page one... good show!