Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Understanding distortion mechanism
Understanding distortion mechanism
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 3rd March 2005, 12:59 AM   #11
adx is offline adx  New Zealand
diyAudio Member
Join Date: Mar 2004
Location: Christchurch
Hi - and yes, you're right, my reasoning above was flawed. Roughly the same level of fundimental is present in the second stage as in the first. The 10dB drop I saw IS a sizeable reduction (1/3rd). I'm sure I could null out the 2nd harmonic with ease, if I didn't have to get an amp ready for a demo tonight...

It's a pity audio signals are still shown using the old log scale tradition, the reality is that our response is closer to linear (pressure) and this is a much more "visually relevant" presentation. Even the a linear frequency scale is better than log for some jobs (like designing speaker crossovers). I was going to write an article or some sort of paper on this at some stage, but that was a while ago now!

Oh well, back to this amp. One day I might even sell one.
  Reply With Quote
Old 3rd March 2005, 01:11 AM   #12
thorstenlarsen is offline thorstenlarsen  Denmark
diyAudio Member
Join Date: Jun 2004
Location: Copenhagen
Hi adx !

Good luck whith the amp. I`m going to sleep to dream about a super-simple amp. Goodnight.

  Reply With Quote
Old 3rd March 2005, 11:14 PM   #13
darkfenriz is offline darkfenriz  Poland
diyAudio Member
darkfenriz's Avatar
Join Date: Jun 2004
Location: Warsaw
hi all
to be mathematically precise:


=Asin(t)+0.25A^2 -0.25*A^2*cos(2t)+...

McLaurin series and powering keeps all secrets


  Reply With Quote
Old 9th March 2005, 08:19 AM   #14
adx is offline adx  New Zealand
diyAudio Member
Join Date: Mar 2004
Location: Christchurch
Woaaa! Maths. At least I verified that (ax^2+bx)^2 results in an x^3 term. That's about as high tech as it gets for me.

I think I see what's going on in those formulas, which I think implies x^n results in only harmonic "n" being added to the output, and demonstrates how exponential distortion gives an infinite number of harmonics.

I modified my program to do y = ((1-yy/10)^3-1)*10 and got a 2nd harmonic as well, as shown. I guess this is because the waveform is offset and scaled before it goes into the "cuber" (something I'd usually associate with cooking or garden waste processing or something like that). Interesting to see all this working.

The gif is clearer this time - the latest version of freebasic doesn't scale graphics slightly off any more. BTW I thoroughly recommend this to anyone wanting to do lash up quick utils and programs without a big learning curve. I've been searching for years.

Well, I got my amp going and debugged (a Gainclone), so onto the next one!
Attached Images
File Type: gif cubed.gif (16.9 KB, 31 views)
  Reply With Quote


Understanding distortion mechanismHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Best CD drive mechanism Hyldal Digital Source 197 23rd January 2017 08:00 PM
A cueing mechanism to buy/DIY theskintman Analogue Source 1 30th June 2008 12:47 PM
Cueing mechanism BluesMagoos Analogue Source 0 1st May 2007 07:17 PM
Philips 12.1T/06 Mechanism stj Digital Source 0 28th April 2004 01:19 AM
Best way to clean CD mechanism? Nicwix Digital Source 1 5th June 2003 07:00 AM

New To Site? Need Help?

All times are GMT. The time now is 08:16 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio