What is responsible for soundstage in a preamp design?

[mik]

Good evening, everyone. Without getting lost in definitions, it is undeniable that there are more euphonic devices than others. We can pretend it's not true, but when listening to the Pultec, it cannot be denied that it sounds good. I myself have experienced that even Jack Erland's version using the 6922 valve coupled with the Lundahl sounds much more vibrant, dynamic, and euphonic compared to the same configuration using a regular JJ ECC 88. There are some particularly fortunate combinations, and the Neumann PEV is much more euphonic compared to its counterparts in the "Danner" format.
Regarding microphone preamplifiers, as has been said many times, they don't sound the same. They have different "engines," and the performance will be different. Why is it so difficult to admit? The preamps from Motu are not great, just like all the preamps from any converter I have ever heard. That being said, in some circumstances, they can be effective, but in most cases, I exclude them and prefer the Api 512, or Neve 1073, or V72 ( love It ) or something in a stand alone format.
M.

 

[mik]

I don't recall saying that but I am not very interested in researching through my old designs to mate one to the Mackie 1202... from 30+ years ago

We have a like button for that. This request sounded almost like homework.

The mixers I designed to compete with the 1202 were bare bones entry level stuff. Sonically the preamps and audio path were solid. The 1202 probably worked OK too... I don't remember if it was the 1202 or 1402 but one small Mackie from back then used an unbuffered insert point. That insert fed directly into a Baxandall tone control section, so if fed from too much source impedance the tone control's changing input impedance could show up as a small frequency response shift. I noticed this by accident when I switched the source impedance of my bench 8903 between 600 ohm and low z. Not a big deal, just a corner cut to reduce BOM cost.

Not by a country mile... But some of the new posters might be happier over there if searching for vague etherial sonic properties.

JR

John, I respect you, I read your posts with great interest, and I always find inspiration to refine my point of view. However, I have noticed that sometimes it seems like you miss the point and express yourself just for the sake of being contrary.
M.

 

[JohnRoberts]

I found the schem for PV 8 - it has the dbl op amp / 2SD786 pres you described.

The PV series was after my time. Tom Stuckman the guy running mixer engineering after me did OK.

JR

Feature-for-feature, pretty comparable to the 1202. I like that it also has channel inserts; not that common on smaller mixers.

 

[JohnRoberts]

John, I respect you, I read your posts with great interest, and I always find inspiration to refine my point of view. However, I have noticed that sometimes it seems like you miss the point and express yourself just for the sake of being contrary.
M.

I was outside in the MS sun, 90' weather doing yard work... I may be running short on salt.

JR

 

[mik]

I have recently been doing something I told myself that I would never do again. That is, record vocals through the onboard preamps of my audio interface. That interface being a fairly cheap Motu M4. I am not a professional recording engineer, just a musician / hobbyist. However, I really need some experienced advice on this.

Here is my dilemma. I have recorded through almost every kind of notable preamp (tube, discrete opamp, neve style, onboard IC opamps). The main difference I have noticed is not the color of the tone (warm vs cold) or (dark vs bright). All of that tone stuff seems to be covered in these modern times with new IC style opamps and even plugin emulations of hardware. The real difference I hear is (2D vs 3D). That is what it seems the newer interfaces and plugins can't replicate. I was wondering what the exact culprit to that issue is?

Let's just leave out tube and neve amps. Let's just compare the difference between a preamp with discreet opamps (2520), and one with IC small form factor things that are in every audio interface. They both have detail, warmth, and clarity. However, the discrete designs has depth with a 3D soundstage. Conversely, the IC opamp is like watching a 2 dimensional black and white cartoon. No depth, just flat.

So what is responsible for the depth and 3D soundstage? Is it the discrete form factor (2520), Or is it the transformers that are usually associated with the 2520 form factor?

In any acoustic or electronic system, there are at most 2 or 3 elements that have a greater impact on the sound than any others, whether it's a guitar or a preamplifier. In electronics, the power supply unit (PSU) has a significant impact. By oversizing the PSU, things change quite a bit: the speed at which the power supply meets the demand to develop the impulse, and thus the amount of current it can deliver based on the requirement, makes the signal more dynamic. If the signal-to-noise ratio is already below -90 dB, it frees up what I call attack transients in the range between 10/15 kHz, which, no longer being suffocated by noise, is perceived and gives the tones more focus. Transformers, if the device is equipped with them, also have a significant impact on the sound. Among the passive components, it is perhaps the one that is most noticeable. The same goes for the active components it consists of. The combination of these elements determines how you perceive the sound.

M.

 

[Rowboat]

Double blind is an academic construct that is unrealistic for anyone without a large budget. Insisting on a peer reviewed study to make every listening decision is not practical. Now if you're talking about having your buddy flip switch and calling that double blind, have at it. It's no better than having a trained listener evaluate it in my opinion.

So how do you know any of this is true? Did you test double blind?

What IS a spitty transient by the way?

Spitty transients are heard as unpleasant-sounding amplitude peaks in mid- and upper mid-range frequencies. They are what I hear when playing fretless bass through a Class D micro amp into an ELF 2X8 bass cab, hoping to maintain my tonality in the upper reaches of the fingerboard, I get earfuls of unmusical high end instead of gentle sonority.

 

[Gold]

Spitty transients are heard as unpleasant-sounding amplitude peaks in mid- and upper mid-range frequencies.

Older crappier opamps like a 741 are well known for that. I think it’s a gain/ bandwidth limitation that produces that type of overload characteristic. A designer would know more.

 

[JohnRoberts]

Spitty transients are heard as unpleasant-sounding amplitude peaks in mid- and upper mid-range frequencies. They are what I hear when playing fretless bass through a Class D micro amp into an ELF 2X8 bass cab, hoping to maintain my tonality in the upper reaches of the fingerboard, I get earfuls of unmusical high end instead of gentle sonority.

Amplifiers with marginal stability can exhibit bad recovery behavior when recovering from clipping. This is considered by serious amplifier designers. Another factor is interstage devices allowed to saturate, that can require extra time to recover from saturation. While still saturated the amp output can stay pegged to a rail, and then snap back suddenly once the negative feedback is back in charge. This would generally sound clicky.

JR

 

[radardoug]

And the OP has left the building.....

 

[k brown]

And the OP has left the building.....

Long, long ago . . .