I know. The next time NAD was mentioned in conversation a few years later, I was informed the model in question had 6db headroom.
lesson learned.
However, NAD can't touch Meridian in sq.
lesson learned.
However, NAD can't touch Meridian in sq.
When your 100 watts X 5 channel surround sound receiver has a skinny cord and a 2 or 3 amp fuse at 120 volts, I think it defies the laws of physics to get 500 watts out of it.
Long ago I did roadie work at rock concerts and 500 watts of pro gear was vastly louder than my "500 watt" stereo. The 100 watt per ONE channel PA amp I just got for announcements at a club I help out must weigh 3 times what my 500 watt stereo does too 🙄
* edit - to be clear I am not thinking a "tube watt" is special, more like some extremely fanciful calculations went into solid state watts that cannot possible resemble steady state output. If I had to guess, my 500 watt stereo would probably be quite lucky to get 100 watts total out of ALL the channels combined.
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I read many stories across the internet blogs about clipping amps and blown speakers.
And I have to wonder...... why is that?
Do these poor losers drive their systems to the max all the time?
Where do they live, that they can crank the volume up to destruction levels?
I'm talking consumer-grade equipment, designed for home use.
Because consumer-grade equipment isn't, or was never designed for such abuse, despite the fact that the volume knob can actually go to "10".
And I have to wonder...... why is that?
Do these poor losers drive their systems to the max all the time?
Where do they live, that they can crank the volume up to destruction levels?
I'm talking consumer-grade equipment, designed for home use.
Because consumer-grade equipment isn't, or was never designed for such abuse, despite the fact that the volume knob can actually go to "10".
Tube watts are no louder than SS watts. The majority of the claim was repeated by guitar players, when SS amps like the Fender Frontman sucked. Funny now they are going back to them and saying, 'they are not bad little amps'. Also the Vox Pathfinder.
But back to the watts. I did an experiment, took a SS amp and output to a speaker at one watt, did the same for a tube amp with 1W measured with a voltmeter. Used a SPL meter to measure the sound output.
No difference.
No surprise to me. Although (guitar related) if you had an amp with poor dampening, one with no negative feedback, you could hear more bass at the resonance and highs with the rising impedance of the speaker as compared to a SS amp. But add some NFB, no difference.
There has been inflated claims for amplifiers from time to time. With a SS amp you do not know what the manufacturer put under the hood but with tube if you have a pair pf EL84's and the claim is 100W, it will be called out rather quickly. Not to say Mr. Tubelab could not coax some impressive numbers out of a tube set, but normally no. Also tubes clip softer. Again, if there is any NFB the scope trace will not look too much different than a SS amp. Again, it is in the design.
But back to the watts. I did an experiment, took a SS amp and output to a speaker at one watt, did the same for a tube amp with 1W measured with a voltmeter. Used a SPL meter to measure the sound output.
No difference.
No surprise to me. Although (guitar related) if you had an amp with poor dampening, one with no negative feedback, you could hear more bass at the resonance and highs with the rising impedance of the speaker as compared to a SS amp. But add some NFB, no difference.
There has been inflated claims for amplifiers from time to time. With a SS amp you do not know what the manufacturer put under the hood but with tube if you have a pair pf EL84's and the claim is 100W, it will be called out rather quickly. Not to say Mr. Tubelab could not coax some impressive numbers out of a tube set, but normally no. Also tubes clip softer. Again, if there is any NFB the scope trace will not look too much different than a SS amp. Again, it is in the design.
A generalization.
Can’t remember the name, it has THD similar to very good SS, high NFB, low Rout and it clipped very hard.
Soft clipping is more an execution thing and to do with amplifier design.
dave
I've been to plenty of parties - sane parties mostly.
I don't recall one gathering that would require destruction-level audio.
For lowend home theater gear yes actually, the big numbers on the box are total BS.. the amp might produce the rated individual channel output in some form* with only 2 channels driven but it will be a fraction of that when all are driven.
*Nobody uses sinewaves to rate audio equipment anymore, the current AES standard specifies a noise signal with 6dB or 12dB crest factor and peak ratings are simply a mathematical doubling of that figure that the amp in question may or may not be able to produce.
But it simply isn't true that all solid state components are junk, cheap audio products are cheap for a reason. A box that contains a ton of audio DSP and video processing, can switch between dozens of inputs, has 5 or 7 or more amplified channels, and costs $399 or less isn't going to do anything really well. The whole "amplifier" is a on single chip and might cost the manufacturer $5, that's all you get for this kind of money.
But spend $1k + on a dedicated 5ch solid state power amplifier and the results will be very different, this amp will totally outclass the cheap HT receiver in every way.
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I bought a Marshall 100 watt SS amplifier.
I opened it up expecting a discrete amplifier.
It had one tiny chip amp in it !
The design was terrible, the fan only blew into the box and the box had no out vent.
There was a big pcb in it but that was for front end processing and the effects module plugged into it the main pcb.
I opened it up expecting a discrete amplifier.
It had one tiny chip amp in it !
The design was terrible, the fan only blew into the box and the box had no out vent.
There was a big pcb in it but that was for front end processing and the effects module plugged into it the main pcb.
I test my amplifiers in my own way....
It's established that AC line voltage/current/wattage are real things, and according to Ohms Laws, it is the way we judge actual circuits, right?
Well, 60 Hz AC is also a part of audio, isn't it?
So, I set the signal generator for 60Hz into an amp with an 8 Ohm load and oscilloscope on it.
I bring the level up to just clipping, and read the resulting AC voltage...
Simple, huh?
If the amp is putting out a clean 25.5 volts AC into that 8 Ohm load, I gather it's putting out 150 watts RMS of "continuous" bass, which is a relatively decent stress test.
To hell with all those "peak power" readings.
That is fine... but a chip amp will fail that test because the manufacturer doesn't spec it with that signal since a steady state sine wave does not represent music. A chip amp will cut it's output back to protect itself after 1,5,10 seconds depending upon how well it's cooled so this test isn't now and never was a good measure of real world amplifier performance.
An SS amp is often rated into 4 ohm load. Use 8 ohm speaker and you halve the available power. 100W amp into 4 ohms becomes 50W amp into 8 ohms.
Valve amp, use the 8 ohm tap, no power reduction.
Valve amp, use the 8 ohm tap, no power reduction.
True, but how LOUD an amplifier will play before gross distortion sets in tends to be very tightly correlated to how much sine wave power it can deliver, and not some instantaneous single cycle peak. Why? Because the best amplifier designs out there have a “dynamic headroom” or additional peak output capability, at 8 ohms, of about 1.5 to 2dB more. This falls out of the math, due to supply voltage regulation, if your transformer is maximally utilized. This additional headroom is inaudible, and the amp can only keep it up for milliseconds at a time. So the real limit on “loudness” is driven more or less by the continuous capability. For an exotic amp with an extremely stiff power supply (and poor power factor that goes with it) you get LESS dynamic headroom. Unless they rate the amp 3dB lower than what it can actually produce. I have seen this. Another thing that may come as a surprise is just how much visible clipping you will see on music waveforms before you hear obvious distortion. So clipping is more common than you think if you play loud at all.
By “how much sine power it can deliver” - this only means how much it can do a few seconds, long enough to make the test. In normal use it won’t need to do it any longer. Old-school solid state amps could for minutes at a time, or even close to indefinitely on amps like the CS800 or BGW750. New stuff can’t unless you spend a fortune. Those old school amps would cost a fortune if you bought one made today. They’d probably charge five grand for a new production 1977 model CS800. You can build one any way you want - it’s your money. Tube amps on the other hand will usually deliver sine wave power indefinitely or at least close to indefinitely. This has to do with the way they are biased. Single ended class A is self explanatory. But class AB push pull tends to run a high quiescent bias compared to solid state. This often puts quiescent power dissipation ABOVE what it is at full power so there is no heat penalty for running it hard. You may run up against screen dissipation limits instead. You can also run tubes as conservatively as you want, especially considering the cost of a retube.
