It is noise what you see, not distortion. The second plot has so high distortion that it is always above noise - you like it, elektroj?
many amps are dominated by noise at lower than full power levels. What one ought to be shooting for is a lack of 'curve' --- such as this quiet CFA power amp's distortion:
THx-RNMarsh
THx-RNMarsh
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Frank obvious you are into Fenky , try reading the bench report , the amp is well, Fenky , at 15k not acceptable , same as the brystons falling on their face below 8 ohm...
Ps: been there done that with both Bryston and Mac, Nothing special
Except that the lowest THD is reached shortly before amp goes into clipping 😉
I very much prefer this kind of amp behaviour:
An externally hosted image should be here but it was not working when we last tested it.
Agree ...
Yes they are longway from Mac of old ......
The system we listened to had a total of 6 meters going all at once , amp , pre-amp , et al , everything had a meter ....
🙂
Actually both curves would sound colored, guess which one would produce that SS GLARE most try to hide from ....
Yeah ..🙂
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Now we're starting to get somewhere ... that 'glare' is distortion due to system misbehaviour, somewhere - it is not due to the amplifier having quite excellent distortion measurements!! The amplifier with poor distortion figures is simply a workaround, to hide that the system has problems, gives the setup a 'Doris Day lens' (who knows that expression?, 🙂) - it's not solving the real problem!!
The amp with 'SS GLARE' is doing a great job of highlighting the system problems, and the latter is what has to be addressed - not changing the amp, and pretending the problem is not there!
So what's causing the SS GLARE, then? - that's the hard bit, this is where troubleshooting comes into it, one needs to work out precisely where the problem or problems are in the system - but this is how the real progress is made!
Just my 2 cents worth, 😀 ...
For once again I would have to agree with Frank that the distortion numbers on that Mac aren't bad before clipping and that is a bunch of power before you get there. So what is the problem with that amp, besides the shutdown under a partial load, which shouldn't happen in an amp that cost so much? Obviously they could use larger heat sinks but what is causing the poor sound quality?
I'm watching the game and Time Warner has messed up all their channels! Everything frozen on all channels!
Apparently so weak technically that John Atkinson ended his measurements with:
... 🙄
Bad sound is a system issue, not a component part issue ...
Whats The problem? Chris voiced that well and Imo it has avg sonics , granted i have only spent 3 hrs in two different systems, listening and the sound was consistently The same , avg. Time for MAC to ditch that transformer and get on with it ...
Just saying ...
Seems Mac has always used a transformer on the output. Some seem to like that way of doing things for matching weird speaker loads.
I have an old integrated Mac in my collection but it isn't working right now. I need to get my hands on an Oscope so I can trouble shoot it. It is an old MA6100 I think or something like that. 90 watts per channel and sound okay, not super but usable.
> Some seem to like that way of doing things for matching weird speaker loads.
I think someone mentioned (along those lines) being able to better keep within
the output devices SOA per achievable output power .
I think someone mentioned (along those lines) being able to better keep within
the output devices SOA per achievable output power .
I had some really old tube Mac's years ago and they always have output transformers and they seem to have carried that into their SS designs for some reason.
Isn't there something about "Choke based PSU's" that they don'tSS Amps with Choke based PSU's tend to not have the famous SS glare ...
work with class b (ab) ......
something like sustaining current ?
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