A NEW METHODOLOGY FOR AUDIO FREQUENCY
POWER AMPLIFIER TESTING BASED ON PSYCHOACOUSTIC
DATA THAT BETTER CORRELATES WITH SOUND QUALITY
BY
Daniel H. Cheever

II. A new audio test philosophy…………………………………………………….. 34
1. Harmonic consonance.………..……………………..………...……....…… 35
2. The sound pressure level dependence of the aural harmonic
envelope……………………………………………………………………….
41
3. Intermodulation distortion.………………..…..…………..…………...…… 49
4. Pre-transient noise bursts.………………..…..……....…………….....…… 51
5. The fallacy of negative feedback as a cure-all……………………………... 52
III. Measurement protocol of the Total Aural Disconsonance figure of merit……...
64
1. Device measurements……………………………………………………... 64
2. A measurement protocol for the Total Aural Disconsonance figure of
merit………………………………………………………………………..
68

• A NEW METHODOLOGY FOR AUDIO

I keep trying but few seem to really be willing to look at real references rather than pass around superficially impressive looking papers that just happen to be on the web

and the AA response
http://www.audioasylum.com/forums/prophead/messages/2816.html

quote:
I'm afraid I haven't got the time to read right now.

Don't bother, it was a terrible piece of work. Amazing he got that thesis passed.

• diyaudio guys opinion

I'll read that. Seems like I remember the fuss, but disregared it as noise. The fuss I mean, not the thesis. The thesis was written for a purpose, so regardless of its conclusions, it had a reason for being. But anyway, I never took the time to read it, got busy and forgot. I'll try to remember this time to check it out and see what Cheever says.

What were your thoughts?

Wayne

some one on diyaudio noted that his evaluation scheme gives his amplifier a better score, and a perfect amplifier will actualy still have a bad score...or something!!
This guy seems a little low on proof after making a statement.

Personally i prefer Douglas self,he seems more facts based
at the moment im scrolling through his amplifier design book,im just starting the part on the 8 distortions of amplifiers...then im getn into the input differential pairs, vas stage and outputs,its SO IN DEPTH ! :-)

I know that the thesis should be read in a way that it was intended for...as a thesis,not as an AES publication ;-)

I would actualy like to make a little 2x20w BJT with a 'warmness' knob on it!! apparently unmatched differential pairs cancel 2nd harmonics quite well when designed well,il look into it :-)

but those cost $$ !

I like having facts not subjectivism in audio. Its always down the the experience ofcourse..but the facts keep you firmly rooted in the swirling storm-market of audio!

oops i contradicted myself..

MATCHED differential input pairs CANCEL 2nd harmonics well!

The THD+N numbers hes stating for his spice models are so low the noisefloor makes it hard to see the distortions.

THe more i read the more i understand.

its great stuff!
now reading how,4ohm loads always distort more :-)
(think of the car audio guys running 0.5ohm loads with quad coil 15"s!)

Also ..how he prefers class A or class B rather than class a/b.
He seems very intimate with his spectrum analyser also! its like his best bud! trusty FFT providing a basis of proof of improvement.

Cheers