Can somebody break it down in layman's terms for me? Why is it that sometimes an amp that has a high watt rating (like, say, a lot of class D amps do) don't seem to always have the balls that much lower rated A or AB amps do? I have heard some people say, "It's not the watts, it's the power supply." Are they talking about big honkin' toroidal transformers? I know opinions vary on a speaker like, say, Magnepans - Maggies love power, right? A lot of people caution against using class D amps to drive them and then will turn around and say that a receiver like the Outlaw RR2160 (rated at 110 watts into 8 ohms) drives Maggies really well! I'm not really asking about differences between Class D, A, or AB so much as I am asking about how can you tell the POWER an amp has from the specs?
Power is the product of the signal voltage * current * the cos(phase angle between them). That cos term and the ability to act as an ideal source as the load impedance drops, is what makes most of the difference when it comes to balls. The cos term varies between +1 and 0 as a factor depending on whether the load is completely inductive or capacitive, or something in between, at a given frequency. A purely resistive load will always be a factor of 1. The impedance, usually simplistically thought of as 8 or 4 ohms, can often vary as low as 1 ohm or as high as 20 ohm, as a composite of resistance, inductance and capacitance. A good indicator of the balls of an amp is if it can double its’ output power down to loads as small as 1 ohm. Most can’t. Then there’s the concept of bridging or strapping an amp to make it a mono-block. In the case of bridging an amp, the two outputs are connected in series, out of phase, potentially doubling the voltage swing, but the same current capability, across the two pos terminals. This can result in a potential V**2/R power increase of 4x. Strapping places the two outputs in parallel, resulting in the same output voltage swing but with a potential doubling of the current capability. You might think that this could also result in an I**2*R 4x power increase but it doesn’t because the required voltage level can’t be met. What this means is that in my opinion, the strapped output results in a much ballsier amp, able to easily drive difficult loads, than the bridging case. The BAT VK tube amps, and Accuphase A200 or A250 comes to mind. If you have a relatively easy load, the bridged case will likely provide greater volume or power levels but will peter out (current starved) if trying for the same levels with a difficult load loudspeaker.
Class D and linear amps have the exact same rail voltage limitations. They often have the same linear power supply front ends. Certainly audiophile Class D amps. They also get more oomph out of the same sized capacitor bank for real music.
It's torque at the wheels that moves a car, not engine torque. I can always convert more horsepower to more wheel torque with gearing.
Many consumer brand receivers have poor ability to drive difficult loads and poor damping factor. The more audiophile brands even though rated lower watts at 8 Ohm tend to be much better.
Everything is designed to a price point. Not doubling in power into 2 ohms (continuous) is often just a factor of the limitation of the transformer. It can only transfer so much power. A nice capacitor bank can give you much of the benefit for real music (not simple sine wave power tests).
The difference in acoustic power delivery between amplifiers regardless of design class eventually comes down to the maximum instantaneous peak voltage the power supply can deliver relative to its RMS average power rating. Music can demand peak to average power ratios as high as 10 times or more the average output. Class D amps are limited to the maximum rail voltage of the power supply. A more traditional power supply with large transformers and very high capacity filter caps can potentially deliver several times the rail voltage on peak demand as the caps discharge before hitting clipping.So an amplifier with deep voltage and current reserves beyond it's nominal rating can deliver higher average power in relation to peak demands than one with a lesser power supply of the same rating.
I don’t care about all the mumbo jumbo on how things are calculated just like I don’t care about how cubic inches relates to horsepower. IME, quality SS amps that doubles its power from 8 ohms down to 2 have been better sounding amps to me. Tube amps sound like they produce more power than its ratings vs SS amps but the tube amps I’ve had or I’ve listened to can’t control the bass drivers compared to SS amps. Nobody here has mentioned anything about how McIntosh amps state there ratings. Most of their higher end models produce the same watts at each ohm. They have autoformers/power guard systems that others don’t, good or bad. I have tested this watt vs current scenario using my old Totem Mani II’s that are very difficult to drive. This was 15 years ago, I had a 200 watt Classe 200 amp that doubles down for each ohm. In my home theater room, I had an audio receiver with a 200 watt rating but didn’t double down or even close. The audio receiver made the Totems sound thin and lifeless. I Took my Totems to my friends audio room that we hooked them up to a pair of Mcintosh 1000 watt monoblocks and they sounded fantastic at very high spl levels. I think the mani’s state wattage up to 150 watts and we were well over 240 watts according to the meters on the amps. I’ve tried many times trying to get buy with integrated amps claiming they have good wattage with high damping claims, but always end up with a separate amp that has the same wattage as the integrated but has much more power that controls the speakers much better than the integrated
I always looked at wattage between Classes of Amps like horsepower. Some cars have high horse power with very low torque. some have lower horsepower with Higher torque. Torque is WATT moves The car.
Chokes on electrical items with a switched mode power supply Halide Bridge USB to coaxial reclocker Akiko Triple AC Power Enhancer Audio Prism Ground Control spades on speakers RCA shorting plugs for inputs on my amp. Akiko Tuning Caps on amp outputs. Akiko Fuse Box Tuning Chip. 1 x Shumann Resonator Chatres SE + power supply
1 x Schumann Resonator CHARTRES Mk3
Black Ravioli pads for amp, Dac and power supply
Vibrapod isolation cones and feet Akiko Universal Tuning Sticks on speaker cables. iFi AC iPurifier. MCRU Mains Filtration plug Mad Scientist Nitro Nano power cables. ’LOA audio tweak’ chip. Signal Ground solutions SGS-1 Groundng Box. 3 x Bybee iQSE - one on power board. High Fidelity Cables MC-0.5 XLR Noise Stopper Caps. Russ Andrews ’The Silencer.’ Audioquest Jitterbug. iFi USB Silencer. SR Orange fuses
redstarwraith All I thought I was doing was asking a simple question. Honest.
Safety behind a keyboard. Seems what some are doing. Their true personality appears. You can't treat your family like this. Or your friends. Workmates wouldn't put up with it either. And it ruins the forum.
In general if an amp can double down (100wats @ 8 ohms, 200 @ 4, 400 @ 2) that means it has a well made power supply and can supply the necessary current. It also usually means there is usually good power reserves to cover transient peaks. The only reason all amps don't all double down is because the designer got cheap and the power supply can't keep up.
No to belabor a point, but someone that accuses others of trolling I understand has even sent private messages to people asking them to report threads they did not like.
Oh come on Clearthink. You can do better than that. I am not sure that rant is even worthy of inclusion in my book, "Clearthink's Practical book of Impractical Rants". I have come to expect much more of you.
Because that would suggest that ALL amplifiers with different operations
classes, types of FET and wiring singel ended/Push pull. Gives the SAME
constant and relationships so only from wattage and resistance you can
get the I and V.
This is correct even though you don't believe it. If a given amp makes a certain power into a certain load, then it will be making exactly the same voltage and current as any other amplifier that can do the same thing.
What might be tripping you up here is output impedance plays a role. If the amp has a higher output impedance, more of its output power will be dissipated in the output section itself rather than the load when presented with a low impedance load. Since no loudspeaker is a flat impedance from top to bottom, this means that different amps can sound different, even though at certain impedances of the speaker they might all make the same power.
audiozenology"amplifier power tests, right or wrong are made into constant resistance loads"
This is true of course when amateurs, hobbyists, and inexperienced users conduct such tests but when performed by experts, engineers, and designers a much more thorough, complete, and extensive composition of tests is undertaken to accurately assess how a Music Reproduction System component will perform in real-world conditions by the end user.
Optimize, amplifier power tests, right or wrong are made into constant resistance loads. The equations I posted are simple extensions of ohms law. All that is required is to use RMS values. They work.
With inductive and capacitive loads there may be other thermal limits placed on the available power, at least with non switching amplifiers.
If you know P and R, then you can calculate I and V.
But I could not really wrap my head around WHY the correct formulas could work to calculate I and V on a amplifier output.
Because that would suggest that ALL amplifiers with different operations classes, types of FET and wiring singel ended/Push pull. Gives the SAME constant and relationships so only from wattage and resistance you can get the I and V.
That is something I don’t believe is true at all!
And I think I found the missing link.. Why you think that we kan use those formulas on the output power for a amplifier!
That is logical when you measure on a constant like between different phase conductors in your home and I believe it is not applicable on the any given amplifier output.
But I can be wrong maybe any other more gifted than I could share a light on the subject. :)
I don’t care what a gullible snake oil voodooist thinks. Because whatever they say is BS. And what you have done here to your system below is most probably the ultimate I’ve seen in voodoo BS
Chokes on electrical items with a switched mode power supply Halide Bridge USB to coaxial reclocker Akiko Triple AC Power Enhancer Audio Prism Ground Control spades on speakers RCA shorting plugs for inputs on my amp. Akiko Tuning Caps on amp outputs. Akiko Fuse Box Tuning Chip. 1 x Shumann Resonator Chatres SE + power supply
1 x Schumann Resonator CHARTRES Mk3
Black Ravioli pads for amp, Dac and power supply
Vibrapod isolation cones and feet Akiko Universal Tuning Sticks on speaker cables. iFi AC iPurifier. MCRU Mains Filtration plug Mad Scientist Nitro Nano power cables. ’LOA audio tweak’ chip. Signal Ground solutions SGS-1 Groundng Box. 3 x Bybee iQSE - one on power board. High Fidelity Cables MC-0.5 XLR Noise Stopper Caps. Russ Andrews ’The Silencer.’ Audioquest Jitterbug. iFi USB Silencer. SR Orange fuses
audiozenology"You make many claims about amplifier performance that are not founded and would not be made by someone with a somewhat deep understanding of amplifier topologies and what drives their performance limitations."
You are really taking you’re newly discovered moral authority, obligations, and superiority to new heights, achieving a position of enlightened wisdom to dispense to the masses at you’re sole determination!
audiozenology"if you post erroneous information that you can’t back up, people like me are quite warranted, perhaps even morally obligated to call it out."
The claim to heeding, following, and possessing a moral obligation certainly places you in a realm far above, beyond, and superior to many in this group and makes me wonder if you’ll be citing the bible next to explain, justify, and defend you’re mistaken, confused, scientifically absurd and laughable technical claims that are rooted in your incomplete, inaccurate, and ignorant grasp of elemental theory. I am still laughing over that convoluted and twisted "argument" you asserted regarding fuses as I recall that completely and totally overlooked induction as a basic electric principal you are "too funny" as Americans would say, so you’re superior "morals" and integrity can’t save you from embarassment but might make you feel better, smarter, and justified because of you're superior character and spiritual "enlightenment."
Who asked you and what was that last post in aid of, to incite more conflict? cretin. I wouldn’t say too much with your reputation for being an "anti Pass Labs" advocate starting threads and posting on it. While at the same time praising anything Class-D.
Your just as bad as sunshine above, no, worse he likes Pass Labs, even though they are Mosfet.
audiozenology but if anyone is stalking, you are stalking me. I posted 6 times in this thread before you did.
And BTW sunshine, not one of my posts were addressed to anything you said in your first 6 posts You are the stalker. Now please don’t stalk!!! Can I make that any clearer
Nice try ghi, but if anyone is stalking, you are stalking me. I posted 6 times in this thread before you did. You are free to post whatever you want, but if you post erroneous information that you can’t back up, people like me are quite warranted, perhaps even morally obligated to call it out.
You make many claims about amplifier performance that are not founded and would not be made by someone with a somewhat deep understanding of amplifier topologies and what drives their performance limitations.
That you don’t even understand the operation of the underlying technology of the product you sell further calls into question your technical abilities which you appear to use to justify the validity of your other statements, since you don’t justify them from a circuit design / architecture standpoint.
You have no idea, all you know is how to stalk someone and put **** on something else they do for a living that’s not even related to this thread. Go away and stop your stalking, you are a pest for a new not even 1 month old member.
When you keep sticking your foot in your mouth and showing lack of knowledge, even about the things you claim to be the expert on, are you surprised I would expect you lack knowledge in amplifiers , things of which you keep making erroneous statements on?
So let me get this right. You design with Cadmium Photocells but you don’t know they are ACTIVE semiconductor devices? That’s right, active semiconductor devices. Period. End of story. Not debatable even.
My gosh. You don’t even know how a CdS photocell works. It does not change its chemical properties when exposed to light. It is a doped semiconductor. Exposing it to light increases the availability of free electrons for conduction.
Teletronix limiting amplifiers, first released in late 1950’s, early 1960’s used CDS Photocells to control audio level. That was later built into other equipment. YOU absolutely did not introduce photocells to audio for level control.
Hello redstarwraith. From all the responses, you can see that opinions differ, and some folks just like to argue. Layman's terms? "Not everyone tell the truth. Manufacturers want to sell stuff." POWER should be a simple matter of math. An amp that doubles it's 8 ohm output into 4 ohms should sound better than one that doesn't. Many ad writers have no idea what they are talking about. Many amp designers feel they make the perfect amp and if your speakers don't like them, too bad. Even today, many amp designers don’t realize that the power supply of the amp is it’s most important section. Some amp designers want to help out the speakers with some electronic wizardry. Some speakers don't like wizards. Some do. And that's why speaker cables matter. In general, small speakers are less efficient than large speakers, but not always.
If you have Maggies (I've had two pair of them and think highly of them), realize they have a weakness; they are less "dynamic" than cone loudspeakers. their diaphragms cannot move large distances and thus cannot move large amounts of air. What they have is near magical clarity and exemplary electrical behavior. With almost any amp, they will sound less dynamic (flashy, zippy, theatrical) than some other speaker. Add a subwoofer if you want more "impact" from your music system. Emotiva's amps do well with Maggies; I suspect Shiit amps will do well also. You can buy them on line and send them back if they don't work well for you. NAD is famous for making amps that "sound bigger" than their ratings. Use at least 14 gauge zip cord for speaker cables. Keep them short if you can. Cables matter. Many highly rated speakers have dreadful electrical characteristics and count on a very tolerant amp to get good results. Tolerant amps tend to be pricey. You can build very good amps, speakers, and cables for relatively little money. If the website lets you, contact me directly for "how to" info.
The room matters more than we like to think. You won't get good sound in a closet full of clothes. Does your room have surfaces that reflect or absorb sound? Speaker placement within the room is critical. Six inches one way or another can make a huge difference. It is a particular problem in the bass. Away from walls is better than close to walls, but I insist on being able to walk across my room without bumping into speakers.
A good 100 watt, class A/B (that means it shifts between two operating modes, A and B), should be enough for most situations, excepting stadiums. Do not rely on advertiser's claims. Your practical experience is more important than anyone's words. Enjoy the hobby!
You adapted the compression circuit from mixers to make a pre-amp billed as passive, though technically not passive.
Wrong again, once again you’ve gone "completely off thread subject" and dare to attack my product (remember what happened last time), again do a search back to the 1970’s when I first introduced it into audio.
Also the signal goes through nothing but a passive device called a Cadmium Photo Cell (CdS cell) that chemically changes it’s characteristics with any sort of light exposure, and which has no electrical active properties running through it at all. https://ibb.co/JmQS31T All this little baby needs is light to make it work, so it’s totally passive https://ibb.co/Q6jKBGZ
Did my research. Stand by my post. You don't seem to have actual amplifier architecture design experience. You adapted the compression circuit from mixers to make a pre-amp billed as passive, though technically not passive. No obvious experience with any serious design of BJT or FET amps.
Yeah whatever, do a search to see what I’ve built in the passed, it may open your eye’s, as for now you can see the forest for the trees, just like in your passed life.
I guess you didn't get a new record for Christmas. Ghi, I think you would be surprised what can be built for a $150 in parts when you purchase in volume.
Oh George, maybe someone will give you a new record for Christmas. Yours appears to be broken.
You have never actually designed an amplifier. That much seems obvious to me. Guessing you don't know much about speaker performance versus damping factor either.
Your holy grail wrt power doubling from 4 to 2 ohms ... Says more about the power supply AND feedback level than the output devices. An amplifier designer would know this.
Oh come on George, I don’t know any amplifier vendor that publishes independent data, only reviewer data.
When I say that it’s Stereophile, Miller Labs, Newport
Test Labs ,ect ect and like that are independent that give you the truth. If you want to believe the BS many manufacturers give you that’s your problem.
As more and more these days the manufacturers are "grossly understating their 8ohm wattage" to make the the 4ohm look like it’s closer to doubling, same goes for the 4ohm to the 2ohm, and Stereophile test confirm it. And if you don’t know this then you’ve been hiding under a rock, and can’t see the forest for the trees. But I already knew this.
It’s easy to drive into 2 ohms with complimentary MOSFETs.
You will not get anywhere near the current performance what same amount of complimentary BJT’s can do into 2ohms. That’s why all the very best amps that deliver huge current into 2ohms are all BJT (bi-polar) again your under a rock
Oh come on George, I don’t know any amplifier vendor that publishes independent data, only reviewer data.
Your comment about MOSFETs is ignorant. It’s easy to drive into 2 ohms with complimentary MOSFETs. Purely an architecture thing. I don’t know why you insist on this repeated ignorant. Please learn more about amplifier design before posting on this. You know the Behringer is rated into 2 Ohm ... Why would you say what you do?
Optimize,
P = v * I
P = v^2 / R
P = i^2 * R
If you know P and R, then you can calculate I and V.
I am not aware of any commerical audio amps designed as current sources ... Not practical as it would not work with off the shelf speakers as it would screw up the crossover operation.
Class-D and complimentary mosfets poweramps fall down miserably when asked to deliver current into 2ohms so they can double the wattage all the way. That's why they never advertise "true" independently tested 8, 4, 2ohm wattage's just before clipping, because the 2 usually goes backward in wattage, indicating sever current starvation or limiting.
Optimize, yes we do know what you are asking if say they give a spec into 8, 4 and 2 ohms which many do..
No they do not. No manufacturer what I have seen have been given what ampere (current) spec into 8, 4 and 2 ohms.
Only wattage and maybe the distortion. We are in the dark of how much current (and voltage) there were when we got the power (wattage).
Internet know hows and reviewers say now and then. "The speaker X need a high current amplifier".. How would they know?! They do not have any other specifications that we all get.. There is specific amplifier designs that are primarily designed to be current sources. So they can have relatively low wattage but for producing that wattage it gives high amount of current and low voltage.. Or are missing something here? Were is the ampere and the voltage in the specifications?
Most tube amps don't have "guts" in the bass due to low damping factor.
You may prefer that or you may not and that will be room / speaker
dependent.
Bandwidth also plays a role, as well as the match between the amp and speaker. You can have an amplifier with very low damping factor that plays bass great, with plenty of guts. If that's a tube amp, just put it on a 16 ohm load rather than 4 and see how gutzy it gets!
Current is just as important if not more than watts
This statement is a common myth and is false. Current cannot exist without watts; they have a simple mathematical relationship. 1 Watt = 1 Volt times 1 Amp; its that simple.
So if an amplifier has the 'current' it will also have the watts- they go hand in hand.
Where we consumer only have wattage then we can not know much of each component the amp gives for example get 100 watts.
Is it 2 amp and 50 volts ? OR Is it 4 amp and 25 volts ? OR Something completely else?
The issue is speakers being matched to amps and this is a historical problem. Most speakers these days are meant to be played on an amplifier that acts as a 'voltage source' which is to say for a given output voltage, that voltage is invariant with regards to load impedance. No amp can actually do that but many can do perfectly well on most speakers but not all. But to further complicate matters not all loudspeakers are meant for voltage sources and these speakers will not sound right unless they get an amplifier that matches them. Some examples of loudspeakers of this type are ESLs, many horn loudspeakers, many full range single-driver loudspeakers, some box speakers both acoustic suspension and bass reflex. So you have to know the intention of the designer! For more on this see http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
With regards to low impedance, in the world of high end audio one of the main goals is to get things to sound real. To this end amplifier distortion is a huge deal because it is distortion that are the differences we hear in amplifiers. Higher ordered harmonics are interpreted by the ear as harshness and brightness even in very small amounts (as our ear has to be keenly sensitive to those harmonics as it uses them to determine sound pressure). Lower orders (2nd-4th) contribute to 'warmth' and 'body'. The ear converts all forms of distortion (THD, IMD, aliasing) into tonality.
With most amplifier topologies it is not possible to add enough feedback in a way that prevents the feedback itself from contributing to higher ordered harmonic distortion. This is at the root of the tubes/transistors debate; the way the industry has gotten around this problem (insufficient gain bandwidth product) is to use an old technique known as 'lying'. They simply don't measure the amps at frequencies where we can see what happens in the range where the ear is most sensitive (Fletcher Munson) so we never get to see the real score. This is why there are amps with no feedback at all and consequently much higher output impedances. The idea with such amps is that tonality caused by distortion can be more important to the ear than actual frequency response errors. Good luck finding all this out on a simple spec sheet.
I've never heard one of these, I like that they used Bi-Polars (BJT's) to achieve this performance into low impedance's as complimentary mosfets would have trouble doing these sort of figures.
While a neat idea, I question the lower voltage rail, then high voltage rail used when even wattage is required for transients or louder passages, as the "sound" characteristics of those output transistors will be different for those two voltages used, I don't know if this is easily detectable while listening or not.
@georgehifi ....thx! Yea, I've seen that video and specs when I was researching some Proton amps. Mind boggling! A tech with 40+ years exp had told me about them when I was looking for info on the Dahlquists. Said he'd owned several sets and had powered them with Bryston, Carver, PL and the Ampzilla. Said the Proton sounded better than any of them. I figured since we're talking low power, high current....I'd ask. Appreciate the info
sejodiren There’s a guy on CL selling this Proton ’beast’. What’s your impression of the review? He wants $750 for it.
This if in good working order >25 years old now (any bad caps have been renewed) it should be a good BJT (bi-polar) amp, at least if the specs are right (typo 175w should be 275w), and increases it’s wattage substantially for each halving of impedance all the way to 2ohms. BTW nice twin R-Core transformer also.
"The D1200’s output clipped at rms 155 watts into 8 ohms 275 watts into 4 ohms 350 watts into 2 ohms
With peaks of 593 watts - 8ohms 1,187watts - 4ohms 1,800 watts - 2ohms,
@audiozenology.....thanks for the feedback. I don't comment on here much.....too much back and forth banter. So I just read and form my own opinion. I've become a lot more 'tech savvy' than I used to be. There's a guy on CL selling this Proton 'beast'. What's your impression of the review? He wants $750 for it. I know they are rare. Not trying to hijack this thread....haha Judging from your answer, you like the Proton specs I'm guessing.
http://www.hifi-classic.net/review/proton-d1200-165.html
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