ATST there is nothing wrong with comparing empirical data that can be measured and expressed in numerical terms. Like comparing the same wattage amps and observing their outcome as compared to each other via empirical data.
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Jad Freer Sisma Mega Thread.
- Thread starter gtirard
- Start date
Andrea Lo
Commercial User
- Feb 21, 2022
- 196
- 843
- 47
- Disclosures
- Jad Freer Audio, Ibanez Guitars, Aluminati Guitars, Citron Guitars, Dogal Strings, Plick the pick
Oh sure, we do that all the time here in the lab. We have ab'd almost any amp available.ATST there is nothing wrong with comparing empirical data that can be measured and expressed in numerical terms. Like comparing the same wattage amps and observing their outcome as compared to each other via empirical data.
Yes, it would be helpful to know which amps were compared with the Sisma.
Personally, I'd like to see frequency response graphs for every amplifier, along with THD, IMD plots, etc.... But the thing is, while I like to see test reports, graphs, etc... too, none of that technical data means much if one doesn't like the tone. And specs often don't tell you much about the sound quality. And with bass gear, tone sculpting and manipulation are perhaps more important than sterile reproduction.
That said, I've A/B'd many CD players and DACs and found reliably discernible differences in sound quality, even though they all measure nearly the same. Recently, I was surprised to find that I preferred the sound of a late 1980s PCM1701 multibit DAC to modern Sigma-Delta DACs. Yet I can't explain why and I'm not sure measurements would either. Similar story with op amps....
Personally, I'd like to see frequency response graphs for every amplifier, along with THD, IMD plots, etc.... But the thing is, while I like to see test reports, graphs, etc... too, none of that technical data means much if one doesn't like the tone. And specs often don't tell you much about the sound quality. And with bass gear, tone sculpting and manipulation are perhaps more important than sterile reproduction.
That said, I've A/B'd many CD players and DACs and found reliably discernible differences in sound quality, even though they all measure nearly the same. Recently, I was surprised to find that I preferred the sound of a late 1980s PCM1701 multibit DAC to modern Sigma-Delta DACs. Yet I can't explain why and I'm not sure measurements would either. Similar story with op amps....
I only use oxygen-free, ethically-raised, free-range, copper cables.
Kidding aside, audio subjectivists and objectivists both tend to make straw men out of their opposition. I see value in both perspectives, but not snake oil. Some aspects of musical sound reproduction are not that easily quantifiable, especially when looking into the psychoacoustic aspects. And when it comes to making music, if it sounds good, then it is good. I say that as someone who has been delving deeply into bass distortion for the past while... not pretty in an objective sense... but the sound is glorious to the ear... well, some ears anyway.
- Feb 12, 2006
- 60,981
- 5
- 220,746
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
If something is not quantifiable, then don’t quantify it incorrectly.
As a data point, virtually all class G/H pro audio touring amps have been replaced by class D amps, these are in products that are not in the least bit budget conscious.
As a data point, virtually all class G/H pro audio touring amps have been replaced by class D amps, these are in products that are not in the least bit budget conscious.
Do you feel there no audible differences between the different classes of amps? So as long as you are not pushing it into distortion, the cheapest/loudest/lightest is the best choice?
Also, when you say one class is more efficient, that just applies to how much power it draws, correct? So 100 clean watts output should be equivalently loud for all classes.
If both are clean (no distortion and no compression) that is not true.
Why wouldn't that be true ?
A tube amp is approximately 2.5 X the output of a Solid State at the same Power output. Because it can carry more voltage on that wattage than a Solid State.
If it is not true. Why is there 100W Ampeg Tube amp on big stage and not 100W solidstate ?
Most solidstate amp that push that much are around 700W.
I heard an Ampeg Tube head 100W, a Darkglass 900W and a Darkglass 500W the same night. The 100W tube head has to my hears a full tone with fat lowend and a big punch, the Darkglass 900W hit me in the chest a bit like the 100W Ampeg but the 500W was ridiculously thin in comparison and the Volume was really high on this one and not that much on the Ampeg
I'm a member on a technical motorcycle board.
When posters post inaccurate information, they are removed by moderators and posters are reminded to stick to the facts. If they don't know the facts or like to confuse them, they are removed.
This mis-information makes me hate it here somedays.
@Franz975, amplifiers are rated for performance by frequency response at a rated distortion level.
Let's say the freq. response for 2 amps is similar and the distortion figure is 5%.
Amplifiers rated at 100 watts, no matter what the type (class A, AB, H, D, etc.), put out the same amount of power.
The tone of the instrument, amp settings, and different speakers can influence ones judgement.
Agreed that a distorted tube amp can be louder, but the distortion figure would be higher.
When posters post inaccurate information, they are removed by moderators and posters are reminded to stick to the facts. If they don't know the facts or like to confuse them, they are removed.
This mis-information makes me hate it here somedays.
@Franz975, amplifiers are rated for performance by frequency response at a rated distortion level.
Let's say the freq. response for 2 amps is similar and the distortion figure is 5%.
Amplifiers rated at 100 watts, no matter what the type (class A, AB, H, D, etc.), put out the same amount of power.
The tone of the instrument, amp settings, and different speakers can influence ones judgement.
Agreed that a distorted tube amp can be louder, but the distortion figure would be higher.
- Feb 12, 2006
- 60,981
- 5
- 220,746
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
There can be the perception of difference in power depending on how overload is managed by each particular design. That said, some designs are intended to be driven into clipping and clip more gracefully than others. This is (or can be) completely independent of class.
Efficiency is defined by Power out/Power in x 100%. Therefore, using my previous example of a 90% efficient typical class D amp and a 60% efficient class G/H amp, if the amps were both rated at say 500 watts rms, at rated power the class D amp would be drawing 500/90% = 500x.9 = 555 watts. The class G/H amp would be drawing 500/60% = 500/.6 = 833 watts. Therefore, it would be correct to conclude that this class D amp is more efficient than this class G/H amp by (833 watts - 555 watts) = 278 watts (the difference is waste heat dissipated by the amp).
This is factually incorrect. A tube amp rated at the same power and same distortion level as a solid state amp will have exactly the same output.
What happens is that IN GENERAL, most tube amps will clip more gracefully and in a more pleasing manner than most solid state amps. This means that it's possible to drive the amp harder into clipping with a tube amp and still find the sound acceptable. This was especially true of older school solid state amps that clipped particularly ungracefully, but in recent years, designers of higher quality solid state products have closed this gap by developing ways to mimic the more graceful clipping of tube amps using a variety of soft clip, compression, limiting and dynamics management methods.
This is all part of the perception which can, when misunderstood, lead to incorrect conclusions even when there are real, perceived differences.
Why is there that much volume difference when I hear a 100W tube amp (clean) and a 500W Class D clean ? :/
Because the Tube one sound way bigger and the solid state one sounded super thin and didn't push that much air in comparison.
Hearing a Mesa Carbine M6 compare to a Darkglass 900W was the same feeling.
I didn't wanted to talk about efficiency but just the output we hear.
The louder guitar amp I heard for the moment was a Mesa Boogie MarkIIC+, 90W, that was way way louder than a 100W solid state guitar amp.
The SS amp was cranked high and it didn't hurt my ears, the Tube one was way too loud at low volume
Andrea Lo
Commercial User
- Feb 21, 2022
- 196
- 843
- 47
- Disclosures
- Jad Freer Audio, Ibanez Guitars, Aluminati Guitars, Citron Guitars, Dogal Strings, Plick the pick
What I read is 100% correct but I would not suggest to get rid of an Ampeg SVT thinking that an ice-power equipped 350W class D head will perform the same. I would ask anyone to try that and then come back here for the perceived differences.
I heard live an SVT (not driven by itself but by a Darkglass B7k) and a 900W darkglass with a B7k in front and the SVT hit me in the chest way more. I don't know about theory on those things like the other but from what I have heard live and at the shop (at the shop was a Darkglass 900W and an SVT3 Pro 375W) I don't think I needed to use theory to know the one that was the louder there.
Still interesting to see a bit of theory for my knowledge
