The Much Coveted Jump Factor - Friend or Foe

[Folsom]

morricab... That's a bit confusing. You say it has nothing to do with power, yet say it's the ability to track the whole dynamic range. You can't track the whole dynamic range if the power runs out before peak... But I agree that I don't think jump factor is related to power (or peak). I think A complete unclipped (most clipping is inaudible in a good amp) swing is just showing SPL capabilities, not jump factor. So I'm back to the definition of earlier, that Ron described. But I don't specifically think that you need horns to have it.

Microphones probably aren't the best at picking up the attack, because they themselves are imperfect. SET + horn can be shifting it back, albeit artificially to some degree. They have velocity and a little bit of distortion, and a little signal exaggeration. That is their "magic". I've heard it be good, and bad. There's no reason to think of any of those attributes as negative IMO. Just take it case by case basis for which equipment pieces you like.

Roger, who said anything about the distortion being a negative effect? I'm saying it's deemed good. It's irreproachable that audiophiles in large quantitative numbers prefer gear that has some, as opposed to vanishing amounts. You do get some that prefer the very low distortion type stuff, but it's rare to find someone that doesn't want to mix a bit.

You might be aiding removing corruptive influences with large grounding straps, but those using grounding boxes are doing the total opposite - and with pleasure and leisure do they like the results. We don't all like the same thing, and not all descriptors that are bad in an objectivist engineering description are bad in audio playback.

 

[RogerD]

Folsom,
When you say distortion are you talking about distortion of the devices ie tubes,transistors? Transformer coloration? Or leakage? Noise?
My first tube amp was a VAC 70/70 which used a 3 position ground switch. Kevin Hayes had employed a eloraborate star ground scheme for the amplifier and the switch actually had a effect on the reproduction. I found this quite interesting.
I agree with you that people hear differently and do gain a preference to a sound. Unfortunately it is a double edged sword...there are trade offs in the status quo.
I believe the high end has crossed a important threshold...,a very limited distortion and noise free paradigm where the total SQ can now bring the listener to new levels of enjoyment...actually hearing all the information captured on the original recording.
Nothing really new here because the removal of common mode noise has been done by studio electricians for years. If recordings were distortion free and common mode noise free and our playback systems were now capable of doing the same..I would expect clean powerful dynamics,great clarity,saturated tonal purity and a holographic dimensional soundstage that provides a exceptional level of realism and suspension of dis belief.
Nothing new here except a greater understanding of methods that actually have a real impact on the audio signal. I call it research and common sense.

 

[Kal Rubinson]

Also Class D's power supplies often mix rather poorly with power conditioners. It's a two factor deal where the Class D supplies are designed marginally for being in an AC environment not by themselves, and that there's nearly nothing on the market for conditioners that is fully compatible with class D power supplies.

Class D amps come with different power supply configurations. Some use switching power supplies and some use linear power supplies and, even ignoring the variations within each category, their interaction with power conditioners and the AC line, itself, will be different. I would not generalize.

 

[Folsom]

You only see a few with linear PSUs. But the topology of the actual amplifier often still has a tendency to be suited for dumping on ground.

 

[stehno]

I appreciate the responses. Even Folsom’s.

Since our auditory skills are all over the map in high-end audio, why rely on our own perceptions of what we think is true? Especially since the invention of google and youtube?

Here’s a video of a live performance of Tchaikovsky’s 1812 Overture as the cameras pan the musicians (who should experience more jump factor than anybody) and a bit of the audience. This is fairly exhilarating, exciting, and otherwise dynamic performance with horns, bass drums, crashing cymbals, cannons, fireworks, bell towers, the works.

I challenge anybody here to point out a single instance where even one participant or observer appears even once to experience anything even close to YOUR OWN definition of the “jump factor”. How about the musicians sitting about 4 feet in front of the cymbals at the 10:00 min mark? Did they even bat an eye when the cymbals clanged directly behind them?

I skimmed a few other 1812 Overture videos like this and could find no evidence of a single participant or observer’s focus, demeanor, posture, or attitude change. Not even when the fireworks or cannons were exploding during the crescendo.

If high-end audio’s highly coveted jump factor is so real in live music, then why don’t these musicians and/or audience members seem to even once reflect that emotional impact? Much less, over and over again especially during the crescendo?

Watching a couple of these videos and my previously shared experience, is making me become a bit more dogmatic about my supposed findings on the jump factor. In fact, I’ll use this opportunity to clarify my definition of high-end audio’s jump factor.

High-end audio’s jump factor can be equated to an unusually and exceedingly pronounced and surprising music note, usually its initial attack, that causes an emotionally startling-like reaction from the listener because the note was larger, louder, and/or closer than anticipated. Since jump factors are rarely if ever found in live performances unless the audience is exceptionally close to the performers, the implication is during playback a jump factor is most always the result of amplified distortions that expands/exaggerates a note’s borders making the instrument sound in some instances multiple times larger than actual size, significantly closer, harsher, and/or louder than expected. Especially in comparison to other surrounding music notes.​

​

In other words, the jump factor is an overly distinct (think unnatural) initial attack of a note that includes one or more unexpected (think unnatural) characteristics induced by amplified distortions that causes an unexpected (think unnatural) emotional response in the listener where in small doses could be misconstrued as a positive, exciting, and dynamic attribute giving a false sense of being there but in larger doses will render the entire playback performance unnatural and unmusical.​

Don’t get me wrong as I’m a huge fan of dynamics and to be honest, for several reasons I seriously doubt there exists a more naturally dynamic playback system than my own. But I’m an even bigger fan of keeping it real.

More importantly, just because something has been believed and propagated in high-end audio for 30 or 40 years doesn’t necessarily make it true. Even if the most renowned speaker or amplifier designers claim something to be true doesn’t make it so. Remember, every last designer’s playback system is just as prone to the effects of the very same distortions as the rest of us.

Now there’s always caveats and conditions. For example. An instrument could be more closely mic’ed over other instruments. There’s always potential for inferior sound engineering or mastering. Or lower playback volume levels would keep jump factors to a minimum. FWIW, depending on the recording and genre, nearly all of my listening volume ranges between maybe 83 and 105db with the overall average being probably about 96db.

Next time you attend any live performance and you’re more than 20 feet away from the soundstage, count how many times you experience anything remotely close to your own definition of this highly coveted jump factor. If the total count is even once or twice, it’s probably the guy behind who unexpectedly sneezed.

 

[RogerD]

I must admit jump factor is rare. IIRC Professor Johnson of Reference Recording said he was disappointed in that his recordings did not sound more faithful to the actual event that was recorded...imagine that. Now play his recording of Crown Imperial...does that giant drum wack in about the middle...scare the crap out of you? Lol
In this case it’s all about moving lot’s of air with headroom to spare. Of course I wasn’t present for the “wack”....but for it to be explosive and concussive in a system many things need to come together and high volume is not required.

Btw movie soundtracks can provide plenty of jump....Red Violin, Previn’s Four Horseman and Raintree County come to mind. Watch out for the cymbal crashes on Four Horseman. Years ago when I had a Hafler 500 and played Copland’s Theme for the Common Man On Telarc. I had the volume set straight up at 12 and those Morel tweeters never had a chance. I don’t do that with my Dyn tweeters....10’oclock is tops and that’s pushing it.

 

[the sound of Tao]

It has not been my experience that any of the effects you are describing increase what most would consider "jump" factor. Exaggerating leading edge detail and creating a forwardness or harshness to the sound is not what is meant by "jump" factor. Jump factor is the ability to startle because the dynamic envelope is greater than anticipated by the listener. This can indeed happen live with large dynamic swings and particularly when close to the action. As you likely know, most recordings are not made with a mid-hall perspective and even most classical recordings have a quite front row perspective. I agree i have rarely been startled in a live concert at mid-hall distance but I have for sure been given a jolt when sitting close to the orchestra or even a piano.

Most playback equipment is hinderd in its ability to track the full dynamic envelope of a musical peak...even relatively small shifts can be blunted or masked. When a system tracks this well you feel that the system is more lively and "alive", this is just as important on the low level end as the high level end, although the low level end will not startle you it might surprise when a small woodwind blat or burp comes up suddenly. The blunting on the high end has a lot to do with speaker's dynamic envelope and not just how loud they will play if you put enough power into them. It is more about instantaneous heating of voice coils and thermal compression (or in some cases dynamic compression from reaching mechanical limits). The lower the sensitivity of the driver, the earlier the onset of a thermal effect. This is why, generally speaking, horns and other high sensitivity designs will track dynamics more accurately. I have found ribbons and e-stats will track faithfully as well but up to a much lesser level...however, this is more mechanical limits rather than thermal ones so the effect is not quite the same in practice. They can have very good jump up to middle volume levels and then sort of just hit a wall, so to speak. Low sensitivity cones just kind of flatten out and the peaks are blunted rather than scaling properly.

The low level dynamic shifts have to do with responsiveness of the drivers to small input signals, their inherent noise floor (including box, driver breakup, losses in the crossover etc.). If a small signal goes into the speaker and the speaker goes "what was that??" then it is likely that small but important dynamic shifts are probably getting lost and a loss of realism and "jump" will be gone.

As for the electronics, well the things you describe are exaggerations of detail likely enhanced by high order harmonic distortion and noise related IMD. This has the effect of exaggerating the leading edge of notes and bringing things forward and flattening images and soundstage dimensionality. I find this to be often the killer of dynamics and especially low level resolution and information (often spatially relevant). I have also found that amplifiers that use significant amounts of negative feedback are lacking in "jump" like a heavy hand sits on the sound not letting it come free. I have also found that Jump has virtually nothing to do with power. My 25 watt SET has far more explosiveness and jump than, for example, a 200+ watt Devialet on the same speaker...even low sensitivity ones (we had this comparison with the 83db Boenicke W5 and it was no contest...people were ho hum with the Devialet and with the SET it was jaws on the floor time).

So, jump factor is the ability of a component and a system to swing the full dynamic envelope without blunting on the high end of the range and without obscurring the low end of the range. It is also the ability to resolve small dynamic shifts (like an flute flutter)in the middle of an orchestral temptest. This unrestricted feeling that comes live but is rarely really there in reproduction.

Not all recordings will allow this either. We become conditioned to what the envelope of our system can do and this is why when you hear a new system that can track the dynamic envelope better than your own you may be startled by some peak even in a familiar piece of music that is particularly but unexpectedly dynamic.

Exaggeration of leading edges and forward "in-your-face" presentation does not fit my definition of "jump" factor.

There are so many good things in this post thanks Brad.

Your explanation of the difference in the way horns, (ribbon and stat) panels and low efficiency cones play out in the way they tend to scale up seems spot on. I currently have all three speaker types and their dynamic responsiveness play out very much as you say.

The LM 508 SET amp with Zotl pre pairing that I have now has been one of the very real finds for me in my current polyamorspeakerous system expansion (a mate has recently accused me of having a three way lol) and this 50 watt SET has all that dynamic explosiveness and real verve that even kicks the Harbeth 40.2s into fantastic lifelike action. But then this same amp is really just purely magically effortless when driving the OB Pap horns on which the amp can scale up with a real striking speed while still completely nailing nuance and micro resolution and still being superbly natural in tone. The jump factor with the horns is utterly and effortlessly mercurial and is still at the same time fantastically fluid and maintains a beautiful kind of unfolding elasticity.

The biggest surprise is the way this SET horn combo is also playing hard and fast and sweet at the same time and then even out rocking the big harbys on some fairly challenging and raw and grungy explorative Jamie Saft fair. Feels live but beautiful and still filled with the energy and rawness of live pub music. Think I might have to consider doing some matching horn sub W bins or scoops and maybe just amp it up a bit more again.

 

[morricab]

There are so many good things in this post thanks Brad.

Your explanation of the difference in the way horns, (ribbon and stat) panels and low efficiency cones play out in the way they tend to scale up seems spot on. I currently have all three speaker types and their dynamic responsiveness play out very much as you say.

The LM 508 SET amp with Zotl pre pairing that I have now has been one of the very real finds for me in my current polyamorspeakerous system expansion (a mate has recently accused me of having a three way lol) and this 50 watt SET has all that dynamic explosiveness and real verve that even kicks the Harbeth 40.2s into fantastic lifelike action. But then this same amp is really just purely magically effortless when driving the OB Pap horns on which the amp can scale up with a real striking speed while still completely nailing nuance and micro resolution and still being superbly natural in tone. The jump factor with the horns is utterly and effortlessly mercurial and is still at the same time fantastically fluid and maintains a beautiful kind of unfolding elasticity.

The biggest surprise is the way this SET horn combo is also playing hard and fast and sweet at the same time and then even out rocking the big harbys on some fairly challenging and raw and grungy explorative Jamie Saft fair. Feels live but beautiful and still filled with the energy and rawness of live pub music. Think I might have to consider doing some matching horn sub W bins or scoops and maybe just amp it up a bit more again.

I can imagine the LM + PAP gives a very lively sound. Big, high sensitivity woofers and horn mid/high gives an effortlessness to the sound. The open baffle I guess really helps on the coloration side of things as well I can imagine. Only a horn bass amps it up more but they are tricky to get aligned right because of the long horn and the time delays involved...

 

[the sound of Tao]

100% the widebander PAP horn with a big iron LM SET is a near ideal pairing. The Zotl pre beautifully dances along the line between speed and richness.

That said the box Harbeth 40.2s are doing something different again and are musically so communicative I am very happy swapping week around between these and the horns.

There is an additional meatiness coming out of the Harbys that is soulful and deeply satisfying and easy. There is a more viscous fluidity with the Harbeth that is alluring. The horns are in some ways more ether and harder to reduce down to a simple description. That said neither can quite energise a space exactly the way the ribbon panels do in the Maggie 20.7s. These are just mesmerising when in full action.

Three very clearly different perceptual states. I could happily live with any of these ... let alone all three. Now, to just work out how I can get the sensitivity of the Maggie 20.7s up just enough that they will also be completely happy with the LM SET. That’d be another version of pure heaven. The word neodymium springs to mind. Maybe that might be worth exploring.

 

[morricab]

100% the widebander PAP horn with a big iron LM SET is a near ideal pairing. The Zotl pre beautifully dances along the line between speed and richness.

That said the box Harbeth 40.2s are doing something different again and are musically so communicative I am very happy swapping week around between these and the horns.

There is an additional meatiness coming out of the Harbys that is soulful and deeply satisfying and easy. There is a more viscous fluidity with the Harbeth that is alluring. The horns are in some ways more ether and harder to reduce down to a simple description. That said neither can quite energise a space exactly the way the ribbon panels do in the Maggie 20.7s. These are just mesmerising when in full action.

Three very clearly different perceptual states. I could happily live with any of these ... let alone all three. Now, to just work out how I can get the sensitivity of the Maggie 20.7s up just enough that they will also be completely happy with the LM SET. That’d be another version of pure heaven. The word neodymium springs to mind. Maybe that might be worth exploring.

Our Dynamikks! speakers do something like both your PAP and Harby, they have 96db sensitivity with a meaty, powerful sound.

 

[stehno]

There are so many good things in this post thanks Brad.

....

Really? I didn’t read morricab’s post that way at all.

I thought I read some confusing contradictions and/or lack of consistency in use of terms and/or definitions. At the very least I’m pretty sure we’re talking apple and oranges here regarding the jump factor.

For example. Morricab said, “It has not been my experience that any of the effects you are describing increase what most would consider "jump" factor. Exaggerating leading edge detail and creating a forwardness or harshness to the sound is not what is meant by "jump" factor.”

I’ve no doubt that’s not been his experience. Remember, we’re talking a characteristic that’s been coveted for 3 or 4 decades. A few questions might be in order.

• What might the sound effects be when a note’s leading edges or borders are exaggerated that create a forward and/or harsh sound?
• At what volume levels does morricab usually listen?
• Could any system generate morricab’s definition of a jump factor at elevator music volume levels?
• Could or should any genre of music be able to generate morricab’s definition of a jump factor? Might a string quartet be able to induce morricab’s definition of a jump factor?
• Music has a tempo and is often times somewhat repetitious. Thinking of this 1812 Overture video how many time during say the crescendo should a sufficiently musical playback system exhibited morricab’s definition of a jump factor? Once, 20 x’s, or maybe 50 x’s?

Morricab also said, “Jump factor is the ability to startle because the dynamic envelope is greater than anticipated by the listener.” Not sure why, but apparently my claims of notes exaggerated beyond their borders by amplified electronics-induced distortions could not possibly be the cause of morricab being startled by a dynamic envelope being greater than anticipated. Oh, well.

Anyway, here morricab used the word startle. Ok, since we all seem to agree that being startled at a live performance is a very real possibility, how many times in that very dynamic 1812 Overture video did anybody look startled? How many times is morricab startled on his own playback system when he listens to a dynamic version of the 1812 Overture’s crescendo? Might it be more than what is counted in this video?

Could anybody here provide ANY video of a serious live performance where any of the musicians or audience members show evidence of being “startled” by dynamic envelopes?

Morricab said, “This can indeed happen live with large dynamic swings and particularly when close to the action.” This seems confusing to me. Being startled, jolted, or jumped is usually the result of a sound that occurs instantaneously or moment in time. I would think a large dynamic swing could not quite fit that description. But I'm open for examples.

Morricab said, “As you likely know, most recordings are not made with a mid-hall perspective and even most classical recordings have a quite front row perspective.” Well, yeah. I’ve been startled by sitting rather close to a mariachi band in a very intimate venue. But if that’s the jump factor we’re supposed to be coveting, how many would buy the recordings of such close-mic’ed performances?

Morricab said, “I agree i have rarely been startled in a live concert at mid-hall distance but I have for sure been given a jolt when sitting close to the orchestra or even a piano.” Ok, maybe now we’re getting somewhere. So morricab has rarely been startled but when sitting close to the orchestra or even a piano he’s been jolted.” By rarely, does morricab imply once or twice in his lifetime or per performance he’s been startled at a live performance sitting mid-hall?

Let’s forget about the jolting. But going back to the rather dynamic 1812 Overture video, why didn’t the musicians sitting 4 ft in front of the cymbals seem startled even once? Or those musicians in front of the tympani or horns? Surely morricab was not sitting closer to the instruments than these musicians were to the cymbals.

Again, maybe if somebody provided a video of a serious live performance where anybody at the performance was startled, jolted, jumped, or even changed facial expression because of a dynamic swing would sure help.

Could it be that morricab is one who has believed perhaps for decades the jump factor is a highly coveted character and is trying to justify its validity? He even admitted that when not sitting close he has rarely heard it at a live performance. Could that performance have been more dynamic than the 1812 Overture performance in the video?

But I also think we’re confusing this jump factor with minimum requirements of a system for this artifact er, um jump factor to even occur.

For example. In an earlier post Ron Resnick was describing a component perhaps an amplifier’s rise and fall time and associating slow or lethargic as part of his definition of a lack of jump factor. But what Ron was really describing with the slow vs fast rise and fall times is what determines a recording’s perceived tempo. So Ron was correct in that a slow amplifier exhibiting a slow rise and fall time would probably prevent any real opportunity for a jump factor to occur but a fast or at least faster amp with quicker rise and fall times is probably a necessary requirement. But slow or fast, the tempo itself is not the jump factor.

Even by just a few admissions in this thread the jump factor is rarely if ever heard in a live performance. If so, why would anybody strive so hard to hear it routinely in our playback systems? I can only think of one reason. In small doses, it induces a certain level of excitement.

I have to believe that excitement from the perceived “jump factor” is cherished and coveted because, in all honesty, many playback systems lack much of the excitement that a live performance delivers. So we have a tendency to cling to anything generating any level of excitement and call it good.

I started this thread to bring the jump factor’s validity into question because of my experience and shared in detail what some rather extreme amplified electronics-induced distortions did to playback presentation and how those effects were quite similar or identical to the jump factor but on turbos. But I think this rather dynamic 1812 Overture performance in the video was able to hammer it home.

Anyway, I’m tellin’ ya, this jump factor thing is just another one of high-end audio’s many old wives’ tales that’s been passed down through the generations.

 

[KeithR]

I think accentuated, unnatural leading edge is often mistaken for jump factor and Class D amplifiers are prone to doing this moreso than others (but not all- see the Spec)

I focus on the "whole note" and don't want exaggerated leading edge or truncated decay. Jump factor is a totally different thing.

 

[stehno]

I think accentuated, unnatural leading edge is often mistaken for jump factor and Class D amplifiers are prone to doing this moreso than others (but not all- see the Spec)

I focus on the "whole note" and don't want exaggerated leading edge or truncated decay. Jump factor is a totally different thing.

Yes, KeithR, as I explained earlier. Even though Class D amps are not digital, because of their high-speed switching modules they will induce a bi-directional digital-like noise that goes back up the AC and into other components or channels. A stereo Class D amp, which is really two Class D amps under one chassis, will share its bi-directional digital-like noise between the L and R channels at the common AC inlet. So there's a nice extra dose of distotions at both channels. And because an integrated amp must borrow AC from one of the channels and then amplified via the gain stage, the distortions are siginficantly worse if it's an integrated Class D amp.

But this does not mean Class D amps are bad by any means. You just need to be aware that stereo Class D amp will perpetuate this distortion. Class D mono-block amps can be just as musical as potentially any other amp. Especially when attached to superior line conditioners.

But if anybody still wants to pursue the jump factor as a highly coveted characteristic, I'd suggest a high-powered Class D integrated amp, crank up the volume to near live music levels, and you'll be there in spades.

 

[Folsom]

Not all classD does as you describe. It might generate "noise", inherently as the carrier signal, but it isn't a guarantee it gets back onto the mains or to the other channel. It does happen with a lot of cheaper ones, but many others have it dwindled down to nothing. And their distortion figures are extremely low, at least phase ones, linear isn't quantified, which is what gives you the "jump" factor you're talking about. But I wouldn't describe classD as having jump factor really, myself. I've heard it with and without.

 

[stehno]

Not all classD does as you describe. It might generate "noise", inherently as the carrier signal, but it isn't a guarantee it gets back onto the mains or to the other channel. It does happen with a lot of cheaper ones, but many others have it dwindled down to nothing. And their distortion figures are extremely low, at least phase ones, linear isn't quantified, which is what gives you the "jump" factor you're talking about. But I wouldn't describe classD as having jump factor really, myself. I've heard it with and without.

I've only dealt with 2 Class D amp manufacturers and based on my limited experiments, they both seem to generate much the same type of bi-directtional digital-like noise. A few insiders whom I hold in high regard tell me it's the nature of Class D amplification. Whether that's true for all Class D amps for certain, I'll never know nor do I really care all that much.

Not that it matters what any other Class D amps may or may not do. In my own case, owning various pairs of Class D mono-blocks from one vendor for which I was a dealer at one time and a pair of Class D mono-blocks from another vendor, I've conducted near identical experiments of 2 mono-block amps with with seemingly nearly identical audible results.

So in the case of these two vendors it would seem guaranteed enough for me they were exchanging noise between the channels. Moreover, the fact that i seemed to have correctly diagnosed the problem with the integrated Class D and the intended remedy cured the problem tells me my limited experience with Class D was right on the money. At least in that case. Moreover, when i informed the Class D amp designer of my findings with his int. amp, he agreed with my findings. For his designs.

The same experts who tell this bi-directional noise likely goes all the way back to the service panel but nobody said here anything about it's guaranteed travel to the mains. But if you say this bi-directional noise stops short of the mains, please tell me where the bi-directional noise stops being bi-directional.

Of the cheaper Class D amps you're experienced that provide this problem would you please provide that list of amp mfg'ers and models? As long as your at it, would you also provide the list of the many others you claim have this distortion dwindled down to nothing? This would be good information.

As for the amps you claim are giving me this jump factor, that you wouldn't describe as having jump factor yourself, and you claiming to having heard it with and wihtout, please explain in as much detail as you like. I'm all ears.

While you're at it, since it seems most have varied definitions of the jump factor, why not start off your response by providing your definition of a jump factor. Just to ensure we're talking apple to apples.

 

[Folsom]

Well, it's not like you've taken measurements...

Hypex amps in the top tier have vanishing distortion, and their power supplies are very low noise. I've heard them for example with class A fronts, and they don't have the "jump factor" type you describe anymore, not in the same way. But that "jump factor" sound is very obvious IMO on something like Crown's series of different amps but they're strangely polite at the same time. Pascal's seemed to be fairly mild mannered, but half way there. ICE depends on the model really. All the ones you find in receivers and all that low level integrated stuff kinda sounds like plastic, and don't have clean PSU's on the same level - filtered but not well. But they often have that heightened edge but might sound really weak.

 

[morricab]

Yes, KeithR, as I explained earlier. Even though Class D amps are not digital, because of their high-speed switching modules they will induce a bi-directional digital-like noise that goes back up the AC and into other components or channels. A stereo Class D amp, which is really two Class D amps under one chassis, will share its bi-directional digital-like noise between the L and R channels at the common AC inlet. So there's a nice extra dose of distotions at both channels. And because an integrated amp must borrow AC from one of the channels and then amplified via the gain stage, the distortions are siginficantly worse if it's an integrated Class D amp.

But this does not mean Class D amps are bad by any means. You just need to be aware that stereo Class D amp will perpetuate this distortion. Class D mono-block amps can be just as musical as potentially any other amp. Especially when attached to superior line conditioners.

But if anybody still wants to pursue the jump factor as a highly coveted characteristic, I'd suggest a high-powered Class D integrated amp, crank up the volume to near live music levels, and you'll be there in spades.

"But if anybody still wants to pursue the jump factor as a highly coveted characteristic, I'd suggest a high-powered Class D integrated amp, crank up the volume to near live music levels, and you'll be there in spades"

It won't give you any sort of jump factor or realistic feeling of dynamics (what I mean by jump-factor in case you missed it) but it is highly likely to give you a splitting headache...

 

[morricab]

I've only dealt with 2 Class D amp manufacturers and based on my limited experiments, they both seem to generate much the same type of bi-directtional digital-like noise. A few insiders whom I hold in high regard tell me it's the nature of Class D amplification. Whether that's true for all Class D amps for certain, I'll never know nor do I really care all that much.

Not that it matters what any other Class D amps may or may not do. In my own case, owning various pairs of Class D mono-blocks from one vendor for which I was a dealer at one time and a pair of Class D mono-blocks from another vendor, I've conducted near identical experiments of 2 mono-block amps with with seemingly nearly identical audible results.

So in the case of these two vendors it would seem guaranteed enough for me they were exchanging noise between the channels. Moreover, the fact that i seemed to have correctly diagnosed the problem with the integrated Class D and the intended remedy cured the problem tells me my limited experience with Class D was right on the money. At least in that case. Moreover, when i informed the Class D amp designer of my findings with his int. amp, he agreed with my findings. For his designs.

The same experts who tell this bi-directional noise likely goes all the way back to the service panel but nobody said here anything about it's guaranteed travel to the mains. But if you say this bi-directional noise stops short of the mains, please tell me where the bi-directional noise stops being bi-directional.

Of the cheaper Class D amps you're experienced that provide this problem would you please provide that list of amp mfg'ers and models? As long as your at it, would you also provide the list of the many others you claim have this distortion dwindled down to nothing? This would be good information.

As for the amps you claim are giving me this jump factor, that you wouldn't describe as having jump factor yourself, and you claiming to having heard it with and wihtout, please explain in as much detail as you like. I'm all ears.

While you're at it, since it seems most have varied definitions of the jump factor, why not start off your response by providing your definition of a jump factor. Just to ensure we're talking apple to apples.

The noise and distortion with Class D you are describing has been in my experience also to lesser or greater degree there (I have more extensive experience than you it seems given I have owned a few of them for experimentation purposes and heard many more at friend's places). The result is the anti-thesis of natural dynamics and jump factor. These are some of the least live sounding electronics I have experienced.

 

[morricab]

Really? I didn’t read morricab’s post that way at all.

I thought I read some confusing contradictions and/or lack of consistency in use of terms and/or definitions. At the very least I’m pretty sure we’re talking apple and oranges here regarding the jump factor.

For example. Morricab said, “It has not been my experience that any of the effects you are describing increase what most would consider "jump" factor. Exaggerating leading edge detail and creating a forwardness or harshness to the sound is not what is meant by "jump" factor.”

I’ve no doubt that’s not been his experience. Remember, we’re talking a characteristic that’s been coveted for 3 or 4 decades. A few questions might be in order.

• What might the sound effects be when a note’s leading edges or borders are exaggerated that create a forward and/or harsh sound?
• At what volume levels does morricab usually listen?
• Could any system generate morricab’s definition of a jump factor at elevator music volume levels?
• Could or should any genre of music be able to generate morricab’s definition of a jump factor? Might a string quartet be able to induce morricab’s definition of a jump factor?
• Music has a tempo and is often times somewhat repetitious. Thinking of this 1812 Overture video how many time during say the crescendo should a sufficiently musical playback system exhibited morricab’s definition of a jump factor? Once, 20 x’s, or maybe 50 x’s?

Morricab also said, “Jump factor is the ability to startle because the dynamic envelope is greater than anticipated by the listener.” Not sure why, but apparently my claims of notes exaggerated beyond their borders by amplified electronics-induced distortions could not possibly be the cause of morricab being startled by a dynamic envelope being greater than anticipated. Oh, well.

Anyway, here morricab used the word startle. Ok, since we all seem to agree that being startled at a live performance is a very real possibility, how many times in that very dynamic 1812 Overture video did anybody look startled? How many times is morricab startled on his own playback system when he listens to a dynamic version of the 1812 Overture’s crescendo? Might it be more than what is counted in this video?

Could anybody here provide ANY video of a serious live performance where any of the musicians or audience members show evidence of being “startled” by dynamic envelopes?

Morricab said, “This can indeed happen live with large dynamic swings and particularly when close to the action.” This seems confusing to me. Being startled, jolted, or jumped is usually the result of a sound that occurs instantaneously or moment in time. I would think a large dynamic swing could not quite fit that description. But I'm open for examples.

Morricab said, “As you likely know, most recordings are not made with a mid-hall perspective and even most classical recordings have a quite front row perspective.” Well, yeah. I’ve been startled by sitting rather close to a mariachi band in a very intimate venue. But if that’s the jump factor we’re supposed to be coveting, how many would buy the recordings of such close-mic’ed performances?

Morricab said, “I agree i have rarely been startled in a live concert at mid-hall distance but I have for sure been given a jolt when sitting close to the orchestra or even a piano.” Ok, maybe now we’re getting somewhere. So morricab has rarely been startled but when sitting close to the orchestra or even a piano he’s been jolted.” By rarely, does morricab imply once or twice in his lifetime or per performance he’s been startled at a live performance sitting mid-hall?

Let’s forget about the jolting. But going back to the rather dynamic 1812 Overture video, why didn’t the musicians sitting 4 ft in front of the cymbals seem startled even once? Or those musicians in front of the tympani or horns? Surely morricab was not sitting closer to the instruments than these musicians were to the cymbals.

Again, maybe if somebody provided a video of a serious live performance where anybody at the performance was startled, jolted, jumped, or even changed facial expression because of a dynamic swing would sure help.

Could it be that morricab is one who has believed perhaps for decades the jump factor is a highly coveted character and is trying to justify its validity? He even admitted that when not sitting close he has rarely heard it at a live performance. Could that performance have been more dynamic than the 1812 Overture performance in the video?

But I also think we’re confusing this jump factor with minimum requirements of a system for this artifact er, um jump factor to even occur.

For example. In an earlier post Ron Resnick was describing a component perhaps an amplifier’s rise and fall time and associating slow or lethargic as part of his definition of a lack of jump factor. But what Ron was really describing with the slow vs fast rise and fall times is what determines a recording’s perceived tempo. So Ron was correct in that a slow amplifier exhibiting a slow rise and fall time would probably prevent any real opportunity for a jump factor to occur but a fast or at least faster amp with quicker rise and fall times is probably a necessary requirement. But slow or fast, the tempo itself is not the jump factor.

Even by just a few admissions in this thread the jump factor is rarely if ever heard in a live performance. If so, why would anybody strive so hard to hear it routinely in our playback systems? I can only think of one reason. In small doses, it induces a certain level of excitement.

I have to believe that excitement from the perceived “jump factor” is cherished and coveted because, in all honesty, many playback systems lack much of the excitement that a live performance delivers. So we have a tendency to cling to anything generating any level of excitement and call it good.

I started this thread to bring the jump factor’s validity into question because of my experience and shared in detail what some rather extreme amplified electronics-induced distortions did to playback presentation and how those effects were quite similar or identical to the jump factor but on turbos. But I think this rather dynamic 1812 Overture performance in the video was able to hammer it home.

Anyway, I’m tellin’ ya, this jump factor thing is just another one of high-end audio’s many old wives’ tales that’s been passed down through the generations.

You are assuming the experience of listening live and recorded are exactly the same and they are not. Excpetations in our own heads will affect whether you can be startled or not. In a live setting you have a different expectation of dynamic envelopes than the reduced experience of hearing reproduced. The musicians hear live all the time and have rehearsed the same pieces over and over...they will not be startled because their expectations are different. Same with the audience. However, I have been startled in a live setting a number of times, particularly once I went to hear Shoshtakovich's 12th symphony...the crescendos were beyond my expectations clearly and startled me. Also, I was in attendance to a home concert with string quintet at close range...there were a couple of moments of at least mild surprise at the surge in the sound.

As you rightly pointed out most systems lack realistic dynamics and we are conditioned through experience to accept this. That is why when a system and recording overachieve it can be startling...your expectation is for "meh" and you got "wow!". This is not coming from this exaggerated leading edge noise hypothesis you have come up with, which would be ever present, but from what I have described, which is why it is only occasionally and with really superb dynamic recordings that it happens...if at all. I never get this from electronica or standard rock music even when played loud. If your hypothesis were correct I should hear exaggerated dynamics and increased "jump" from noisy and/or distorted gear...this really doesn't make a lot of sense and flies in the face of experience. No rock recording startles or gives me the live feeling of dynamics...I have almost exclusively experienced this with classical very wide dynamic range recordings.

As for my listening levels, they are probably lower than most on this forum. Howveer, I don't get startled at low listening levels only somewhat louder ones. That said, I have at low-moderate levels had my attention particularly caught where I went "hmmm that was interesting!" but again not with heavily compressed recordings and not with ANY Class D or SS amps.

 

[christoph]

It won't give you any sort of jump factor or realistic feeling of dynamics (what I mean by jump-factor in case you missed it) but it is highly likely to give you a splitting headache...

Jump factor like you want to jump up and leave the room?