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Review and Measurements of Schiit Aegir PWR Amplifier

March Audio

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I - like Amir - use the point where the THD starts degrading severely (i.e. "shooting up") as the point of clipping. Schiit uses 1% THD. I can see where they're coming from, but unless the amp clips softly (which the Schiit doesn't) I think it's more honest to use the point where the THD+N graph shoots up.
Also note that Stereophile tends to use quite few points in the sweep, so the difference in output power between the data point with THD below 1% and the data point with THD above 1% can be quite significant. That's another way of "cooking the books".

I'm not suggesting that one method is right and another is wrong, only that I find "my" method (which Amir also happens to use) to be more honest. Then again, my honesty will probably limit my business potential as my output numbers will always be lower than "the other guy's".



That's no longer a case of reading a graph in a certain way then. That's a case of a "music power" spec. Or perhaps a made up "spec". Either way, I'm disappointed that stuff like this makes it to the "recommended" list.

Tom
Ive mentioned this recently to @amirm that ASR should settle on a consistent THD figure for amp power ratings as at the moment its still variable. Hypex, like Schitt use 1% and I think this is fairly common throughout the industry. However in mine, and probably most peoples opinion is thats too high.

Its a little arbitrary what figure to settle on so long as its not considered a significantly audible level of distortion. Equally I dont think we should shoot for ridiculously low figures.

0.1% or 0.01% Personally I actually consider 0.1% a pretty sensible compromise.

Opinions everyone?
 
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maty

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* SS -> 0.1 %

* Tubes -> 1%

It always bothers me to see specifications of class D amplifiers at 1% and 10%, something too usual.
 

audimus

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Heh. I suppose that if you define marketing as "never, ever be honest about the cons of your products" then yeah, any sort of honesty about your product's weaknesses is bad marketing. That is certainly one way to market one's products, but thinking that's the only way to market is... a limited understanding of marketing. Honesty (or the appearance of honesty, if we're being cynical) is a strong marketing tactic and that's always been their brand. Example from their $99 Magni 3 FAQ, which is AFAIK largely unchanged from their Magni 1/2 marketing copy:
This is not about being honest. I am guessing you are more in a technical career than a marketing career who thinks what the latter does is mostly dishonest. I was in that boat once until got slapped around by market reality when I got a broader role.

There is a difference between dumping everything about the product and only putting the best part of your equipment in the description. The section I quoted only appeals to hard core tech geeks. Saying it still runs hot is unnecessary in that section. Have a faq somewhere if that happens to come as a question that people ask. Or link to a technical white paper.

Just because you don’t dump everything into the beginning paragraphs of a overall description, it is not being dishonest.

That description won’t attract anybody that doesn’t know a Class A from a Class foobar nor care about such things which is probably 90% of the potential customer base. That is why I say they are marketing idiots. The fact that a few tech geeks resonate with that tech porn does not make them good marketeers.
 

Jimster480

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Interesting amp... but I am confused as to who it would be for.... because with such low power output you aren't going to power many speakers to any decent volume.
I think people would be better off with cheaper self powered bookshelf or satellite speakers than to buy amps like this to power such small speakers?
 

Fred Jacquot

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Isn't "know your customers" the rule number 1 in marketing? If they target tech geeks in the 30-40's, their communication seems quite appropriate.
I know they are not amongts the most popular brands here, but I personally find their communication refreshing in a sector where the simple idea of having fun seems like a sin.
Not sure that being different is a mark of idiocy.
 

maty

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Talking about class A amplifiers, atm (jalejos) not only assembles Hypex and PURIFI modules, it also designs its own class A.

[Spanish] https://www.acoustic-technology.com/es/blog-atm/etapa-de-potencia-modelo-epm50

to English:

* https://translate.google.com/translate?sl=auto&tl=en&u=https://www.acoustic-technology.com/es/blog-atm/etapa-de-potencia-modelo-epm50

* https://www.translatetheweb.com/?re...om/es/blog-atm/etapa-de-potencia-modelo-epm50

[ EPM50 power stage development

...Based on our EPM1 model (of which there will be a new update shortly) we have developed a new model that will have more output power, about 50W (just double that of the previous model). For this we will use 50% more output transistors that will supply more current, thus raising the power.

We start with the power supply that is based on a 400W toroidal transformer of very low noise and low dispersion, high speed rectifier diodes and a CRC filter with Panasonic metal oxide resistance, Wima polyester capacitors for RFI / EMI elimination and Mundorf MLytic series electrolytic capacitors with very low resistance and a total capacity of 132,000uF. ]

[PDF] http://www.mundorf.com/english 1.1/Broschuere Einzelseiten/MLGO.pdf

[IMG, link] http://maty.galeon.com/WP-imagenes/hum/Mundorf-MLGO-table.png
 
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audimus

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Isn't "know your customers" the rule number 1 in marketing? If they target tech geeks in the 30-40's, their communication seems quite appropriate.
I know they are not amongts the most popular brands here, but I personally find their communication refreshing in a sector where the simple idea of having fun seems like a sin.
Not sure that being different is a mark of idiocy.
First, targeting a very small niche market if that was indeed by design is not a winning strategy. Second, it is not doing the right marketing even for tech geeks correctly. This forum is over-represented by tech geeks and yet most don’t like this company’s products. Because tech geeks also look for proof of technical quality of the product, not just shop talk.

So, rather than assume that they know exactly what they are doing, it would be far more likely that they are communicating the only way they know how, and that is with tech porn. The latter would certainly look refreshing to tech geeks but not sufficient if the products are “Schiit”. Except perhaps for a certain group of people that talk meaningless tech porn in the units they buy like the size of their subwoofers, the number of speakers and amps you can embed in a car, how loud their systems can go up to, etc., and for whom this company might look like a technical genius. Sort of the blue-collar equivalent of the people who buy Bose lifestyle products.
 

Fred Jacquot

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You are assuming that all geeks are electrical engineers. That's an assumption like another.
What is redeshing is not what you call tech porn, it's the "all this is not really serious".
 

Willem

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Whatever their marketing, I don't like this product for two simple reasons:
1 It does not have enough power for nearly any situation
2 The technology is not energy efficient
 

AudioSceptic

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Ive mentioned this recently to @amirm that ASR should settle on a consistent THD figure for amp power ratings as at the moment its still variable. Hypex, like Schitt use 1% and I think this is fairly common throughout the industry. However in mine, and probably most peoples opinion is thats too high.

Its a little arbitrary what figure to settle on so long as its not considered a significantly audible level of distortion. Equally I dont think we should shoot for ridiculously low figures.

0.1% or 0.01% Personally I actually consider 0.1% a pretty sensible compromise.

Opinions everyone?
The trouble with the 1% point is that the curve is usually very steep by then, near vertical in many cases, so you can get a huge difference in the power figure depending on the resolution of the measurements (or graph if estimating it visually). If a figure has to be used, rather than a "break point" where the curve starts a rapid rise, then 0.1% makes a lot more sense than 1%.
 
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These might work with my 4367.
 

peng

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For THD+N measurements, I prefer the following test conditions:

For preamp output

0.01 %THD+N FBW at 1 Vrms and rated output (or 2 Vrms) using 20-20,000 kHz stimulus source signal sweep, I am not sure if it is necessary to also specify the load impedance (e.g., 1 kOhm minimum?) or we can assume the input impedance of most power amps are too high for this to be a factor, even in the case of AVRs that don't have preamp mode so the pre-out has to drive the internal amp as well as the external amp?
If 20-20,000 sweep is not possible/practical, okay then I would settle for 1 kHz as long as the harmonics vs frequency measurements are also provided.

For power amps (including AVRs) output, I would like to see measurements for 0.1% THD+N at 1/4 W and rated output into 8 and 4 ohms, two channels driven simultaneously and continuously (according to FTC standard), 20-20,000 Hz sweep.
 

KSTR

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"Industry standard" has been to state power at 1% and/or 10% distortion, sometimes 0.1% as well. So, no standard, effectively.
And remember power has to log-weighted. The difference between 100W and 150W appears to be huge ("look Ma, 50% more power!"), but is insignificant actually, an SPL increase of only 1.7dB which translates to a precieved loudness increase of about 10% or even less, depending on sound pressure levels. Going from 80dB to 82dB "at the onset of clipping" is different than going from 110dB to 112dB, at the listening position.
Also, when the power amp doesn't use a stabilized regulator or SMPS, the mains voltage is affecting the power reading big time and every power test should either monitor the mains voltage or use a precision mains generator.

Personally, when I had to make statements of output power of a product, I've often just eye-balled the onset of distortion on the oscilloscope (something like 3% or so), read rms voltage from the meter, de-embedded any mains voltage difference to nominal, round up a litte to give a nice number with a '0' or a '5' for the last digit and call it a day. It's good enough. Stating power with 3 significant digits like 134W and using that for product ratings is nonsense. Even two digits is overkill.
 

KSTR

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And, as Mr. Nelson Pass coined it: The first Watt is what counts for sound quality. Unless you're clipping the amp all the time (ever wondered why consumer power amp seldom have clipping indicators?) max power isn't that important. And if you clip a 20W amp, you'll clip an 100W amp almost equally hard. For a voltage headroom of 4...5, which would prevent clipping if you clipped your amp way too often before, you need 20...25 times the power...
 

anmpr1

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Its a little arbitrary what figure to settle on so long as its not considered a significantly audible level of distortion. Equally I dont think we should shoot for ridiculously low figures. 0.1% or 0.01% Personally I actually consider 0.1% a pretty sensible compromise.

Opinions everyone?
In the days of toobs a lot of manufacturers specified power ratings at 1% within a FR range. For SS, 0.1 seems like the bare minimum that ought to be achieved in a production unit. The fact that some brands are not even offering full specs is unacceptable IMO.
 

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