Personally with respect to guitar amps, I haven't found that feedback from speaker to tubes was ever really useful, to me, in creating a more euphonic sound. I always preferred the sound of head based amps over a combo because of the reduced microphonics/feedback (however you would like to describe it). The feedback from speakers to the guitar strings(and in some cases to semi hollow body guitars), well now you have something that can be harnessed for musical expression. In the case of feedback to preamp tubes the result is not controllable, at least not at a musical performance level............however there is certainly many ways to reduce the problem(rubber o-rings over the tube, shock mounted tube sockets, etc.
Vintage mojo... What is it exactly?
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Bo Deadly
Well-known member
Feedback from speaker to guitar is very important yes. Especially at really loud levels. But feedback from the speaker output to the PI (like in a twin, deluxe, "presence" control in a JTM-45s, etc) expands and flattens the frequency response considerably. Consider that J. Garcia played through only the pre of a twin and then fed that into McIntosh amps that were way tighter than a honky guitar amp.
Agree with you on the FB loop from OT sec to PI. I was talking about acoustic feedback from the speaker causing "pleasing" microphonics in the preamp tubes. I'm not sure I get your point about the twin pre into McIntosh amps, but then I wasn't a fan of Jerry's guitar sound.
soapfoot
Well-known member
The 21-year-old version of me would've bristled at what I'm about to say, but... I've come to believe that the most consistent source of "vintage magic" might be the way the overall user experience colors our expectations.
I'm sure many of us have had experiences where with there were two mixes of a song--one that accompanied a fantastic-looking video, and a different mix for audio-only album release. With the impressive-looking video playing, that first mix sounds great. With the screen off, it's usually markedly inferior to the "album release" mix.... even if nothing changed except turning off the video!
In a similar vein, using something like a Fairchild 670 or old Marshall Plexi is something of a total sensory experience. It's very easy to be drawn into the overall feeling created by the giant bakelite knobs, huge VU meters, iconic make/model name, large price tag, awareness that we've long coveted this thing (or that our heroes used it)...
True objectivity under these circumstances seems almost superhuman. Younger, cockier me would've thought myself an exception to this, but that's just ego. The more experienced I become, the more uncertain I become of the distinction between "extreme discernment" and "superstition."
I'm sure many of us have had experiences where with there were two mixes of a song--one that accompanied a fantastic-looking video, and a different mix for audio-only album release. With the impressive-looking video playing, that first mix sounds great. With the screen off, it's usually markedly inferior to the "album release" mix.... even if nothing changed except turning off the video!
In a similar vein, using something like a Fairchild 670 or old Marshall Plexi is something of a total sensory experience. It's very easy to be drawn into the overall feeling created by the giant bakelite knobs, huge VU meters, iconic make/model name, large price tag, awareness that we've long coveted this thing (or that our heroes used it)...
True objectivity under these circumstances seems almost superhuman. Younger, cockier me would've thought myself an exception to this, but that's just ego. The more experienced I become, the more uncertain I become of the distinction between "extreme discernment" and "superstition."
Soap,
Very important aspect here. This also why glittering user interfaces are so freakin' important to how plugins sounds
(I reuse this recent GS post):
And yes, I'm very aware that with my commercial Gyraf range I'm harvesting some of this effect too, BUT: I defend myself with the fact that I go out of my way to ensure maximum coherence between user interface and its description of actual (although often subjective) function as primary goal - trying NOT to mislead my user's ears by going the other way around. And as I mention above - "the other way around" has been seen in hardware pro audio, some times to a scary degree - and not at all always purposefully deceitful.
/Jakob E.
Very important aspect here. This also why glittering user interfaces are so freakin' important to how plugins sounds
(I reuse this recent GS post):
Do not underestimate the function of the user interface - it is of primary importance in the quest to have emulations sounding like their origin
Reason is that perceived auditory impression is strongly informed from environment cues and habits - to a degree where it sometimes resemble hallucination
This what hifi lives off. And no, it's not make-believe or want-to-believe - it's nature is suggestional, closer related to hypnotically induced hallucinations. This also why hifi discussions tends to get so emotionally heated: They actually and really HEAR that effect that we can't measure or demonstrate - and that can't be repeated in blind tests.
To understand the effect, think of that time you turned the treble up on that hihat during that wildly stressed recording session, only to later discover that eq was bypassed. Rethinking the situation, you WILL remember actually hearing the boosting going on. But as I did, you probably passed it off as a temporary flaw. It's not.
Emulation-plugin user interfacing simply harvests effects like this.
Last time I talked to one of Soft tube's development engineers, he told me that they still extract something like half the perceived sound quality from the interfacing - off course depending on how such aspect is quantified. And mind you, these guys are not kidding, if anything they're among the heavier players in good-sounding emulation business..
Another aspect forming environmental cues to plugin perfection is telling the ever-occurring very public story about how NOW the plugin is fully perfect (the old version wasn't), and with this and that celeb endorsing it, we're legitimizing your use of it..
I just recently realized that if we could somehow harvest this effect for music, not gear, we could make things shift to a whole new level.. Still working on that part though
/Jakob E.
edit:
Note that I'm not in any way implying that using this effect is limited to plugins/emulations - I see examples of pro audio hardware that heavily preys on this effect too..
And yes, I'm very aware that with my commercial Gyraf range I'm harvesting some of this effect too, BUT: I defend myself with the fact that I go out of my way to ensure maximum coherence between user interface and its description of actual (although often subjective) function as primary goal - trying NOT to mislead my user's ears by going the other way around. And as I mention above - "the other way around" has been seen in hardware pro audio, some times to a scary degree - and not at all always purposefully deceitful.
/Jakob E.
I like that idea.Something along these lines might have been partially attempted already by the many 'remastered' classic albums. Some of which, at first listen, might be 'better' or more 'modern'-sounding from a purely technical or engineering point of view, but which often fall short in aesthetic terms -- or let's say they run a risk of losing 'their mojo' (here aesthetic expectation). Personally I like things ('music) that has some sort of quirk (clearly noticeable or not). But I guess you mean something different.
I alluded to perception bias back about 40 years ago but probably didn't call it that, when discussing the "Meter readers" vs "Golden Ears" debate. I suggested decades ago that product designers need to study the ergonomic or psychological factors that influence how people perceive products and use those tools in new designs to increase product satisfaction.
Over the years I had many deep discussions with a fellow console designer (now RIP) about the sundry subtle factors that influenced console user's perception of quality.
JR
soapfoot
Well-known member
I appreciate that these "user experience" factors are being approached here in a manner beyond dismissiveness, because I do agree that it matters--even to the end result of the work.
Assuming a vintage analog synthesizer versus a plug-in emulation: Even in a world where the two could be definitively proven to perform identically, interacting with the old piece of hardware would almost certainly impact the creative and thought processes of the performer. They'll produce different work!
This is not trivial.
Assuming a vintage analog synthesizer versus a plug-in emulation: Even in a world where the two could be definitively proven to perform identically, interacting with the old piece of hardware would almost certainly impact the creative and thought processes of the performer. They'll produce different work!
This is not trivial.
Some have described the hand stamped faceplates I make as retro. I find that interesting as they don’t reference any past pro audio design I’ve ever seen. They are home made looking. Besides the OKW knobs and NKK switches made from modern looking plastic there is only aluminum. The only indicator as to era is plastic of a type that wasn’t used more than 30 years ago. Handmade is assumed to be old.
One of the many aspects of circuit design I know nothing about is electromagnetics, but I won't let that stop me having a crack at describing an idea I've had running around in my head for a while now...
Sometimes I play around with imagining a piece of vintage gear, for example a Gates STA-Level, not as a collection of tubes and wires through which audio signals pass, but as an assemblage of all the electromagnetic fields created by each component and the current. Each would contribute to the whole field of the device, and things like component placement and wiring influence of the overall shape and behaviour of this field, through which the audio passes. If this is a useful way to imagine a circuit's behaviour, then maybe the best sounding pieces of gear (with 'mojo') create an electromagnetic field that has its own input to the overall sound, kind of like harmonic resonance but magnetic rather than sound waves. Spacing of transformers and alignment of cores is something that springs to mind, but I might be overstating the influence of these factors in overall sound...
Stephen
Sometimes I play around with imagining a piece of vintage gear, for example a Gates STA-Level, not as a collection of tubes and wires through which audio signals pass, but as an assemblage of all the electromagnetic fields created by each component and the current. Each would contribute to the whole field of the device, and things like component placement and wiring influence of the overall shape and behaviour of this field, through which the audio passes. If this is a useful way to imagine a circuit's behaviour, then maybe the best sounding pieces of gear (with 'mojo') create an electromagnetic field that has its own input to the overall sound, kind of like harmonic resonance but magnetic rather than sound waves. Spacing of transformers and alignment of cores is something that springs to mind, but I might be overstating the influence of these factors in overall sound...
Stephen
Indeed, all components in a piece of hardware react together in a way that is not on the schematic.
One quite notable case is guitar combos, where the loudspeaker's vibrations are transmitted to the tubes and introduce a specific distortion that several musicians have noted as being part of the sonic signature.
To a lesser point, layout impacts the distribution of parasitic coupling between stages, which often results in instability or even oscillations. Fixing these issues often result in changing the overall tone.
A famous example is the Fender amps of the CBS era, where the layout was changed for productivity reasons, which resulted in very retive amps that needed drastic measures to tame. These amps were not considerd sounding as good as their predecessors.
Usually, these effects are really of second order and may be perceptible to a fraction of users/listeners. Anyway, since they are not easily predictable, most designers tend to minimize them from the start, by caerfully separating power stages from low-level ones, thoroughly decoupling power rails and orienting transformers in a way that minimizes interaction.
Most of the designers of coveted vintage gear were very much aware of this and tried to minimize unpredicted behaviour.
One quite notable case is guitar combos, where the loudspeaker's vibrations are transmitted to the tubes and introduce a specific distortion that several musicians have noted as being part of the sonic signature.
To a lesser point, layout impacts the distribution of parasitic coupling between stages, which often results in instability or even oscillations. Fixing these issues often result in changing the overall tone.
A famous example is the Fender amps of the CBS era, where the layout was changed for productivity reasons, which resulted in very retive amps that needed drastic measures to tame. These amps were not considerd sounding as good as their predecessors.
Usually, these effects are really of second order and may be perceptible to a fraction of users/listeners. Anyway, since they are not easily predictable, most designers tend to minimize them from the start, by caerfully separating power stages from low-level ones, thoroughly decoupling power rails and orienting transformers in a way that minimizes interaction.
Most of the designers of coveted vintage gear were very much aware of this and tried to minimize unpredicted behaviour.
Barn Finds. Although I lost my mojo a decade and a half ago I do recall enjoying random finds. Tube Amps and Pedals mostly.
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