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Micro Bass Heads, why doesn't everyone use them?
- Thread starter Ironderby
- Start date
So if I have a benchtop power supply that is fixed voltage and variable current (say 5V at 0-1 amp) - it's a digital?
It's either on (5V) or off (0V)...
On the speaker terminals of a class-D amp, what switch-like states are on or off?
The same way a class A amp does.
What you're missing is that Class-D (generally) doesn't involve a conversion of an analog signal to digital. It involves the conversion of one type of analog signal to another type of analog signal. A different encoding scheme effectively.
Kind of like AM and FM are two different ways of modulating a signal for transmission - but both are analog.
That's been my point to. Is the actual audio from the instrument being converted from analog to digital at any point in the power supply? If not, no argument.
randysmojo said:
Agreed.
It has been said before in different wording here, but what it boils down to, is that Nofrets seems to suggest that any electronic device with some kind of discrete switching is inherently a digital device... Which is not the case of course, there are many transistor-based devices that are 200% analog.
A pulse width modulation signal can only be described digitally if you would apply a sampling rate rule to it. Since the pulse width in class D amps is analog (i.e. it can be any value, not just binary), you could see that as having a virtually infinite sampling rate, which is only limited by how fast the FETs can switch (a few nanoseconds, I believe. Nothing to be concerned about).
Read the while thread, still confused. lol. All I know is my pf 500 sound amazing and is not 2 grand and 80 pounds.
I appreciate the spirited debate on this thread! 
I think class D being a relatively new tech requires some public observation and comparison.
My interest is to explore questions and begin to think in new ways to help ourselves understand aspects of this new tech.
Although I believe class D or SMPS does not process signal input in the truest digital sense (involving A/D/A conversion of an input analog signal), I do believe some of the engineered elements possibly exhibit some "digital-like' comparisons in function.
The Truth About Digital (Class D) Amplifiers — Reviews and News from Audioholics
I honestly believe that many new digital/analog technologies are blurring previously conceived definitions of what is digital….. which isn't necessarily a bad thing.
After all, the entire concept of digitizing (quantizing) music is to more accurately and efficiently capture, edit or manipulate, represent and emulate continuous original analog waveform more effectively. Our ears hear in analog. Or do they? Or do the terminating neurons? More questions, more states blurring the lines between wave-like and particulate qualities….analog and digital properties.
Perhaps the class D doesn't quantize the original analog input signal, but perhaps it does somehow quantize dynamic changes in volume perception and/or wave amplitude? I am just asking!
Is this why I felt/heard a dynamic difference in the class D amp I owned? I honestly don't know, but I am asking.
In other words how does class D "decide" what switches are on or off and how does it interpret/manage amplitude thresholds for these on and off states? And do these thresholds affect what we hear? This is where I hypothesize possible "digital-like" behavior.
Specifically, what set of rules governs the on and off states of the switches? The individual switches? The entire set of switches? Are all the switches on? Are all the switches off? What determines which are on and which are off? If some are off, does that potentially mask some of the analog wave input? Does the pathway for one switch represent the entire frequency response of the input signal or are they assigned limited frequencies? Or are the switch functions defined by amplitude solely? How many switches are there?
I don't know the answers....but I am asking. Maybe some of the answers are proprietary to the individual manufacturer?
The biggest question to me is: does class D or SMPS interpret analog waveform (with respect to the original analog input waveform) more accurately or less accurately than older technology or amp classes?
Like with all new tech and their advent (CD's, cell phones, and more), the improvement of this new tech usually goes through multiple improvements and upgrades. Perhaps our dialogue here might facilitate some new ideas and improvements?
I am excited to see the evolution of this micro tech! I am not completely "onboard" with it yet, nor am I completely against it either. I am gathering more info though.
"Imagination is more important than knowledge"…Albert Einstein
And here is why I like this forum (my own ego aside....yah right LOL!!)
Musicians Are Probably Smarter Than The Rest Of Us
PEACE
I think class D being a relatively new tech requires some public observation and comparison.
My interest is to explore questions and begin to think in new ways to help ourselves understand aspects of this new tech.
Although I believe class D or SMPS does not process signal input in the truest digital sense (involving A/D/A conversion of an input analog signal), I do believe some of the engineered elements possibly exhibit some "digital-like' comparisons in function.
The Truth About Digital (Class D) Amplifiers — Reviews and News from Audioholics
I honestly believe that many new digital/analog technologies are blurring previously conceived definitions of what is digital….. which isn't necessarily a bad thing.
After all, the entire concept of digitizing (quantizing) music is to more accurately and efficiently capture, edit or manipulate, represent and emulate continuous original analog waveform more effectively. Our ears hear in analog. Or do they? Or do the terminating neurons?
More questions, more states blurring the lines between wave-like and particulate qualities….analog and digital properties.Perhaps the class D doesn't quantize the original analog input signal, but perhaps it does somehow quantize dynamic changes in volume perception and/or wave amplitude? I am just asking!
Is this why I felt/heard a dynamic difference in the class D amp I owned? I honestly don't know, but I am asking.
In other words how does class D "decide" what switches are on or off and how does it interpret/manage amplitude thresholds for these on and off states? And do these thresholds affect what we hear? This is where I hypothesize possible "digital-like" behavior.
Specifically, what set of rules governs the on and off states of the switches? The individual switches? The entire set of switches? Are all the switches on? Are all the switches off? What determines which are on and which are off? If some are off, does that potentially mask some of the analog wave input? Does the pathway for one switch represent the entire frequency response of the input signal or are they assigned limited frequencies? Or are the switch functions defined by amplitude solely? How many switches are there?
I don't know the answers....but I am asking. Maybe some of the answers are proprietary to the individual manufacturer?
The biggest question to me is: does class D or SMPS interpret analog waveform (with respect to the original analog input waveform) more accurately or less accurately than older technology or amp classes?
Like with all new tech and their advent (CD's, cell phones, and more), the improvement of this new tech usually goes through multiple improvements and upgrades. Perhaps our dialogue here might facilitate some new ideas and improvements?
I am excited to see the evolution of this micro tech! I am not completely "onboard" with it yet, nor am I completely against it either. I am gathering more info though.
"Imagination is more important than knowledge"…Albert Einstein
And here is why I like this forum (my own ego aside....yah right LOL!!)
Musicians Are Probably Smarter Than The Rest Of Us
PEACE
I appreciate the spirited debate on this thread!
I think class D being a relatively new tech requires some public observation and comparison.
Class-D isn't new technology.
The first patents on it for audio are from 1959.
Using tubes.
Patent US3011025 - HIGH POWER AMPLIFIER - Google Patents
As long as the pulse width of the PWM signal is analog, nothing is being quantized.
There are a number of ways to generate a PWM pulse train - the simplest being feeding a comparator with a triangle wave and the signal.
Invalid Link Removed
Depends on the amp.
That really isn't something that depends on amplifier class.
Except Class D isn't new.
The way I understand class D technology (and maybe the reason why you might hear a difference between class D and class A, for example) is, that there is a certain "dead zone" in a transistor, where the switch is neither on or off, but somewhere in-between. This effect seems to be more apparent in class D amps than in class A or B.
That "dead zone" causes a small unwanted voltage drop which in turn results in harmonic distortion. The voltage drop can be countered or buffered by a capacitor to an extent, so that the signal is effectively interpolated between subsequent transistor switches.
I might be totally off on electronics theory here, but that's what I understand from various literature. So yes, you could argue that if all of the above is correct, a class D amp will be potentially slightly less accurate in reproduction of the source signal because of the introduction of low harmonics distortion. I do still fail to see where the digital vs. analog argument comes into play then, though
That "dead zone" causes a small unwanted voltage drop which in turn results in harmonic distortion. The voltage drop can be countered or buffered by a capacitor to an extent, so that the signal is effectively interpolated between subsequent transistor switches.
I might be totally off on electronics theory here, but that's what I understand from various literature. So yes, you could argue that if all of the above is correct, a class D amp will be potentially slightly less accurate in reproduction of the source signal because of the introduction of low harmonics distortion. I do still fail to see where the digital vs. analog argument comes into play then, though
The way I understand class D technology (and maybe the reason why you might hear a difference between class D and class A, for example) is, that there is a certain "dead zone" in a transistor, where the switch is neither on or off, but somewhere in-between. This effect seems to be more apparent in class D amps than in class A or B.
That "dead zone" causes a small unwanted voltage drop which in turn results in harmonic distortion. The voltage drop can be countered or buffered by a capacitor to an extent, so that the signal is effectively interpolated between subsequent transistor switches.
I might be totally off on electronics theory here, but that's what I understand from various literature. So yes, you could argue that if all of the above is correct, a class D amp will be potentially slightly less accurate in reproduction of the source signal because of the introduction of low harmonics distortion. I do still fail to see where the digital vs. analog argument comes into play then, though
Thanks Alban!
This seems like a highly possible and reasonable observation to me!
I am not sure there is an absolute explanation for what I am hearing, but I enjoying asking questions to find out more!
I appreciate your answer.
I freely admit I do not have the answers and knowledge, but I do enjoy learning and even speculating!
Right or wrong, I just wanna learn!
My digital/analog comparison is more philosophical regarding the minimal qualifications for something being digital. When I started workin on my masters in computer science, my professor always had us pay attention to where we thought something "becomes" digital. The definition can be difficult to interpret (below just being one).
http://en.wikipedia.org/wiki/Digital
Of course the simplest state being the binary discrete nature of 1's and 0's or any analogous comparison.....like binary switches either being on and off.....which is all a computer microprocessor is. If computers are digital, is an abacus (primitive computer) digital? Is a microprocessor a glorified abacus on steroids?
Drawing the line between digital and analog can be challenging with respect to scope, and scale.
Even the performance frequency of a "digital" microprocessor can be plotted as a sine wave.....which of course does not preclude it's digital nature, but does show the interplay of analog and digital interpretation.
PEACE
I highly doubt you could identify class-D vs. other amplifier topologies in a blind test. I suspect what you heard is something particular to the voicings of the class-D amps you used.
For me - it's quantization. If there is no data quantization (outside that imposed by physics) it's analog, if there is data quantization it's digital.
If computers are digital, is an abacus (primitive computer) digital? Is a microprocessor a glorified abacus on steroids?
Yes and Yes.
Not quite sure what you mean there... but if you've ever seen LVP (laser voltage probe) of an on-die clock signal, they look frighteningly sine wave-ish in the highest speed CPUs.
If I have it right, the original question to start this post was "Why don't more players use Micro Bass amps" para phrasing... I do not have the answer to that question as I don't use one myself, but after reading what this discussion has turned into. I can say that I know why I'm not interested in science, math and engineering... Man, I'm busy playing bass in a band, not building watches... Sine wave, Topology, Rails, Dead Zones, I'm envious of your knowledge, but NOT... Enjoy your chatting...
IMHO - there appears to be a little technophobia by some about micro heads.
There shouldn't be.
They sound and work great for most people under the bell curve.
You can pick up a micro head with one digit
There shouldn't be.
They sound and work great for most people under the bell curve.
You can pick up a micro head with one digit
BurningSkies
CRAZY BALDHEAD
- Feb 20, 2005
- 27,956
- 20,348
- Disclosures
- Endorsing artist: Dingwall Guitars
In the realm of people thinking that they don't have enough power or headroom, I think they're not really getting where this can be going. Because they ARE light and small, depending upon how you design you can get WAY more power and headroom for the same or less money, given the same footprint and weight.
For eight pounds and 2 rack spaces, I can get as much voltage swing as is possible from a standard US outlet. And with more voltage comes better low end reproduction and volume.
For eight pounds and 2 rack spaces, I can get as much voltage swing as is possible from a standard US outlet. And with more voltage comes better low end reproduction and volume.
They're already here. Getting smaller and lighter and better all the time. All this obsession with "heavy is better" is just silly.
http://www.talkbass.com/forum/f4/arnopol-8-cabinet-winner-848274/
http://www.talkbass.com/forum/f4/acoustic-cab-shootout-845758/
Personally speaking, I think it all boils down to sound. I used to use a really nice Eden combo with semi parametric eq and compression etc,but once I heard Markbass I absolutely fell in love. While I wouldn't consider them in the micro, mine only weighs 6lbs, it has a tube pre and pumps out more actual volume at 800w with one markbass 410 than my sansamp w a 1400w power amp and 410 + 212 (avatar).
I have no trouble moving a head that weighs 20-50 lbs. So a micro head doesn't give me any advantage at load in/load out time... although I certainly love the micro heads - they are cool and I may buy one eventually. It's the weight and size of the cabinets that gets problematic.
bongomania
Commercial User
Technically speaking (on paper), people shouldn't be able to hear a difference between tubes and solid state.....but many do. Would love the opportunity to witness an objective more scientific cross testing of amp topologies via bass!
Gonna google it.......really haven't checked for any resources.......gotta be something!
Is anything in nature quantized? Another question my prof loved to inflict on us! LOL!
And if anything is quantized, nature or not, does it become data?Gonna google it and check it out! Sounds like quantum computing is getting closer if I am not mistaken! Sweet!
All good stuff! Appreciate the exchange of ideas!
PEACE
