How much wattage do you use, on average?
- Thread starter b-rider
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I think we can both agree that no class AB amps have such disproportionately large power supplies. If you want an amp with a power supply that disproportionate to your power needs, you'd need to look well into triple figures wattage ratings.
Poultrygeist
Lunatic Member
When folks like to post how extremely powerful their amps are I'm reminded of this quip from Paul Klipsch.
"Bragging about input power is like bragging about how much fuel your car can burn"
"Bragging about input power is like bragging about how much fuel your car can burn"
Pass said something similar comparing throttle peddles to volume knobs and having to turn them to 3 o'clock to get adequate volume. It's perfectly fine if it gets you the speed or volume you want.
Pyrrho
Super Member
If you look at the numbers on the scale on the left of each graph, the solid state amplifier is more linear at low power than the tube amplifier, for the entire range shown. The fact that the distortion goes down at higher power levels means it is vastly more linear at those higher levels. So, that solid state amplifier, as far as can be told from the data you have given, is just better at all power levels. It is more linear at low power and much more linear at high power. It has less distortion at all power levels that are shown in the graphs (from 1/10 of a watt on up).
So, the evidence you have provided is in favor of high powered solid state, not what you originally seemed to be asserting. Being higher power does not cause it to have more distortion at 1/10 of a watt; it has less distortion at 1/10 watt.
My statement was "solid state amplifiers are more linear as they approach rated output" you asked for data proving as such, you even quoted that exact statement and asked for proof, you have your proof. And now that you have your proof you want to sidestep out if it lol. If you like I can copy and paste my statement here if you want to dispute such.
As for how much distortion at either end, that is a $9,000 amplifier lol. If I felt the need, which I don't, I could easily pull up graphs where the solid state amp didn't look as good at flea wattage output.
Just so there's no confusion on just what you asked for.
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Nope. You can easily find some that exceed the joules per watt ratio of yours.
DIY F5-35 joules/25 watts = 1.4
Audio Research REF75SE-520 joules/150 watts = 3.4
Parasound JC-1+-1240 joules/400 watts = 3.1
Atma Sphere MA-1-600 joules/140 watts = 4.3
My amp runs both triode and tetrode. In triode mine comes close:
VTL MB-450-250 joules/200 watts=1.25
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Pyrrho
Super Member
Yes, that is what I asked regarding this post:
The point being, the information you posted does not support the idea that lower powered amplifiers have less distortion at low power levels than high powered amplifiers.
Having more power than needed is not a problem, which your evidence proves.
Having high distortion at low power would be undesirable, but having a high powered amp does not mean that one must have high distortion at low power.
I don't have 25 watt F5's.
And where did you get 35 joules for an F5 power supply? It's more like a minimum of 200 for a stereo power supply, and the power supply in mine will belt out a hell of a lot more than that.
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Mea culpa. They are 30 watt DIY F5s. That reduces the ratio to 1.2.
Did the math. 120,000 uF running 24V rails. Similarly, Nelson recommends between 23 and 25V.
I'm thinking you don't understand the formula: J=C*V*V/2
For a power supply with 120,000 uF to have 200 joules, the rail voltage would need to be 58V. Or, if by stereo pair you mean 240,000 uF, then the rail voltage would need to be 41V. Or, assuming your design follows Nelson's recommendations, it would need 700,000 uf for 200 joules.
Clearly voltage is the key determinant. My power amps have but 1650 uF of C - but run 550V rails! Conversely, the LPS 1.2 power supply for my ultraRendu endpoint has 60 farads of C - but only at 7V.
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Sure it does.
Not necessarily. I purchased an AR Integrated amp to drive Advents when I was 15. At high power, it sounded great. Resolution, however, fell apart at low levels. This was a valuable lesson that I had never fathomed. Avoid designs that are largely class B!
Nine years later, I purchased a Threshold Stasis 3 amp which proved to be the antithesis of the Acoustic Research. It resolved down to a whisper.
I would hardly characterize this Pass Lab amp as exhibiting "high distortion at low power"
No, no, no, Grasshopper! That's not how this works at all!
First of all, the power supply needs to deliver a constant 90 watts just to idle one channel. That idle load is less than 1/8th the rated output of that power supply. If all that the power supply could output was 35 joules, it would be impossible to set the idle, much less melt the outputs, and I've done both.
Joules have a time domain function and I'm not sure how that factors into this. A joule is the heat from 1 amp at one volt through a 1 ohm load for 1 second. If the amp is idling 1.4 amp at 32V per output device, it's obviously dissipating way more than 35 joules. Power supplies are much more than capacitor banks.
Sorry, clearly you don't understand the formula.
The measure of energy storage has nothing to do with an amp's idle current.
Output devices dissipate current. Joules is a measure of power supply energy storage.
Matters not to me whether or not you accept the definition.
I use a spreadsheet, but here's a web resource:
https://www.electronics2000.co.uk/calc/capacitor-charge-calculator.php
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Take two Levinson amps, both with the same THD figures at the extreme left and at their rated outputs. The only difference between the two is total output power, one 30watts, the other 300watts.
Superimpose the two graphs, both at .005 THD at the extreme left, the lower power amp will be more linear all the way until it runs out of gas. The more powerful amp will still not be at the most linear part of its output until it also approaches "it's" rated output.
That still doesn't change the fact the lower powered amp is more linear at lower levels, whether you can hear it or not. But this may explain why so many report their lower powered amps sounding so sweet with Klipsch, and others stating they don't come alive until they give them some juice from their powerhouse amps.
A good argument for having multiple amps, that's my story and stick'n to it lol. And if you tell the little lady any different I'll deny it.
Superimpose the two graphs, both at .005 THD at the extreme left, the lower power amp will be more linear all the way until it runs out of gas. The more powerful amp will still not be at the most linear part of its output until it also approaches "it's" rated output.
That still doesn't change the fact the lower powered amp is more linear at lower levels, whether you can hear it or not. But this may explain why so many report their lower powered amps sounding so sweet with Klipsch, and others stating they don't come alive until they give them some juice from their powerhouse amps.
A good argument for having multiple amps, that's my story and stick'n to it lol. And if you tell the little lady any different I'll deny it.
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Show me where I said "high" distortion lol?Not necessarily. I purchased an AR Integrated amp to drive Advents when I was 15. At high power, it sounded great. Resolution, however, fell apart at low levels. This was a valuable lesson that I had never fathomed. Avoid designs that are largely class B!
Nine years later, I purchased a Threshold Stasis 3 amp which proved to be the antithesis of the Acoustic Research. It resolved down to a whisper.
I would hardly characterize this Pass Lab amp as exhibiting "high distortion at low power"
View attachment 1855643
Look at my last post, you're reading things into what I'm typing. One amp being more linear doesn't mean the other has "high" distortion, only "more" distortion.
Done here, return to your regularly scheduled bickering.
Sorry, clearly you don't understand the formula.
The measure of energy storage has nothing to do with an amp's idle current.
Output devices dissipate current. Joules is a measure of power supply energy storage.
Matters not to me whether or not you accept the definition.
I use a spreadsheet, but here's a web resource:
https://www.electronics2000.co.uk/calc/capacitor-charge-calculator.php
I don't understand your formula because it's not a formula for calculating joules. I joule is the force of a volume of current over a time span. Your formula doesn't describe anything like that.
And yes, output transistors DO dissipate watts in the form of heat. They're basically big resistors when operated in their linear region. That warm stuff coming off my amps isn't current. It's heat.
Sure. In post #152, you quoted Pyrro's comment:
"...does not mean that one must have high distortion at low power."
And replied "Sure it does".
Maybe you didn't mean what you posted lol.
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