Axiom Home Page Forums General Discussion Stereo Anyone need a new amp with some umph!!!!

I do love a good amp thread.

You guys are great.

But it sure would look cool!

Rick,


Now, THAT'S funny!

I got down to 24 db. Whatever that means in terms of percent THD.

I got down to -30dB before I couldn't tell.

Here a page which converts between distortion attenuation (what the test measures), and % THD: http://www.sengpielaudio.com/calculator-thd.htm

-30dB is 3% THD!

And to go back to my example. 0.2% THD is -54dB, while 0.02% is -74dB.

Good to know.

Let's not forget that the THD is also at max output, lower volume levels would have much less THD, this leads to the idea of having extra horsepower available being a good thing in that the THD you hear(or don't hear) would most likely be non-existent at most listening levels with higher powered amps.

And Tom, it is still working great. So good in fact, I had to stop myself from buying another one just "because" when Guitar Center was advertising a 70% off sale over Labor Day ($400 - 70% = CHEAP). The fan noise fix may discourage some, but for the price the fear should be minimal. And to my surprise, it only makes detectable heat when the high current rails kick in, which is very seldom. (ala, FredK's comment about only never really needed the whole 800 watts.)

But when it's time to really enjoy the music, it gets hot, but sounds great. None of the sonic limits of my Denon AVR (which i can still find via A/B switching when I use the center ch signal from the AVR - certain sounds have a harshness that stands out (to me anyway!).

As for stats, I found the Peavey amp I tried had noticeable hiss, and a related (I think) higher THD and SN Ratio. So don't assume all pro amps are the same. Try them first.

Thanks Rick, cool site now I just need to know what the different tests represent. I ask because my scores varied quite a bit depending on the test. For example on the “octave” test I hit -45dB four out of four times but in the others I varied anywhere from a little above to slightly below the mean. Is any one of those tests more representative of “real” music?

I did the test with both my Axiom M80s and Sennheiser HD600s and got results that were mostly dead on with a few exceptions where they were within +-3dB of each other.