The No.1 Website for Pro Audio
 Search This Thread  Search This Forum  Search Reviews  Search Gear Database  Search Gear for sale  Search Gearslutz Go Advanced
What about harmonics above 3rd?
Old 29th August 2015
  #31
Lives for gear
 
bogosort's Avatar
Quote:
Originally Posted by Ienjoyaudio View Post
Ok. I think I got it now.

The 3rd order harmonics are associated with Neve products. However this is not because of the class A design but rather the particular op-amps used.

2nd order harmonics can be produced from class A gear however again it depends on the circuit design and the op-amps used in the circuit.

Is that correct?
No, if you want to be correct then say that asymmetrical distortion emphasizes even-order harmonics while symmetrical distortion emphasizes odd-order harmonics. But the truth is that it's not useful to think this way. Real-world processors aren't perfectly symmetrical or asymmetrical, and real-world signals -- such as music -- don't produce simple harmonic distortion products. Trying to characterize audio processors by their ratios of even to odd harmonics is a bit like trying to determine the personality of a person while he's sleeping.

Quote:
Another question. How does all this apply when designing a digital converter? Seems like an A/D could be greatly affected by these design principles.
The foremost design principle in audio converters is linearity, which means no distortion. Obviously perfect linearity is impossible, but it's much easier to design a linear system when you don't have to amplify a signal. More challenging is making an amplifier behave linearly at high gain settings. Ironically, this is precisely what console designers work hard to achieve.
Old 29th August 2015
  #32
Deleted 7f9cade
Guest
Quote:
Originally Posted by bogosort View Post
No, if you want to be correct then say that asymmetrical distortion emphasizes even-order harmonics while symmetrical distortion emphasizes odd-order harmonics. But the truth is that it's not useful to think this way. Real-world processors aren't perfectly symmetrical or asymmetrical, and real-world signals -- such as music -- don't produce simple harmonic distortion products. Trying to characterize audio processors by their ratios of even to odd harmonics is a bit like trying to determine the personality of a person while he's sleeping.



The foremost design principle in audio converters is linearity, which means no distortion. Obviously perfect linearity is impossible, but it's much easier to design a linear system when you don't have to amplify a signal. More challenging is making an amplifier behave linearly at high gain settings. Ironically, this is precisely what console designers work hard to achieve.

Very interesting. I'm a complete noob when it comes to signal processor design and electrical engineering. Thanks for sharing this.
Old 29th August 2015
  #33
Quote:
Originally Posted by Deleted 7f9cade View Post
Another question. How does all this apply when designing a digital converter? Seems like an A/D could be greatly affected by these design principles.
Besides the usual THD and IMD, you have another factor, harmonics related to the clock, not the waveforms. Those distortions are offensive as they are not harmonically related to the input signal.

To learn these effects there are a couple of tools you can try out.
One is a Hammond organ. Pull out the white drawbars, those are 2nd, 4th, 8th, all harmonically related to the even orders. Then pull out the black drawbars, those are the odd partials, not so musical.

For the digital clock distortions and related harmonics, listen to a Pro Tools mix.
Old 29th August 2015
  #34
Lives for gear
 
XKAudio's Avatar
 

Very happy to see this topic up.

If your newb to this stuff a great things to lookup:
Overtone series
Fundamental frequency
Harmonics
Harmonic distortion (odd and even)
Non harmonic overtones (noise) vs harmonic overtones (tones)

That last one is the biggest ahha moment for me in understanding tonality in sounds for composing and mixing in general
Old 29th August 2015
  #35
Lives for gear
 

What a great thread. @ bogosort - you have a clear way of explaining things, thanks.
Old 29th August 2015
  #36
Lives for gear
 
XKAudio's Avatar
 

Quote:
Originally Posted by Matt Nolan View Post
But, for sake of explanation, musically speaking, 2nd harmonic is an octave, 3rd harmonic is an octave and a perfect 5th, 4th harmonic is a double octave, 5th harmonic is a double octave and a major third, 6th harmonic is a double octave and a perfect 5th, 7th harmonic is a double octave and an augmented 6th / minor 7th, 8th harmonic is a triple octave, 9th harmonic is a triple octave and a second, 10th harmonic is a triple octave and a major 3rd, 11th harmonic is where the odd harmonics start to fall in-between notes, 14th harmonic is where the even harmonics except the power 2 ones (16th, 32nd, 64th, etc.) start to fall in-between notes.

^ this was huge when i understood that harmonies sound good because of the fact that they are in the harmonic overtone series, which really was just a ratio of the fundamental frequency and the harmonic.

Ei, the 3rd partial which is the 2nd harmonitc/overtone is a 5th over the fundamental frequency. which is also the most simple harmony, being 2/3 ratio between the two.
Old 30th August 2015
  #37
Deleted 7f9cade
Guest
Quote:
Originally Posted by Jim Williams View Post
Besides the usual THD and IMD, you have another factor, harmonics related to the clock, not the waveforms. Those distortions are offensive as they are not harmonically related to the input signal.

To learn these effects there are a couple of tools you can try out.
One is a Hammond organ. Pull out the white drawbars, those are 2nd, 4th, 8th, all harmonically related to the even orders. Then pull out the black drawbars, those are the odd partials, not so musical.

For the digital clock distortions and related harmonics, listen to a Pro Tools mix.
The PT mix thing make sense to me. Although I couldn't describe why I don't like it with the accuracy you do. Summing mixers and Antelope clock here.

For everyone reading this is a moot point. Lets keep this thread on circuit design and its related harmonics. Please no summing or clocking debates. Please?


Another question. There seem to be a lot of talk about the op-amps. How much do they contribute to the harmonic characteristics of the circuit? BLA always wants to change the op-amps on their converter mods, any unit, always the first thing they seem to mention is an op-amp upgrade.

Are they just one part of a the entire circuit design? or do they play a bigger part?

Thanks
Old 16th September 2015
  #38
Deleted 7f9cade
Guest
I decided to bump this thread up as I think its some really good stuff and the conversation should continue.

Can anyone tell me more about specific op-amps and how they contribute to the harmonics of a circuit? Do op-amps have the most influence when it comes to the harmonic response of any given signal processor?

Thanks
Old 16th September 2015
  #39
Lives for gear
 
GreenNeedle's Avatar
 

Quote:
Originally Posted by bogosort View Post
ACrunchy jazz chords don't typically sound good.
Maj7#11, M6, min 9, any add2 etc. depends on the rig but jazz chords can sound amazing with distortion. It can be very voicing dependent though.
Old 16th September 2015
  #40
Lives for gear
Quote:
Originally Posted by Ienjoyaudio View Post
I decided to bump this thread up as I think its some really good stuff and the conversation should continue.

Can anyone tell me more about specific op-amps and how they contribute to the harmonics of a circuit? Do op-amps have the most influence when it comes to the harmonic response of any given signal processor?

Thanks
It is an interesting thread, and I don't have an answer about opamps, however it is strange how no one even mentioned cascading partial lattices. As evident in this instrument, the sort of swirling partials in lattice form are synthesized by the mixtur-trautonium, and early electronic instrument:

https://www.youtube.com/watch?v=-tQQEChMq1A

This is one of the later versions of the instrument, which Sala built himself.IT's crazy how he is able to control the harmonic series while still playing melodically and harmonically. Gorgeous string sounds.
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump