Welcome, Guest. Please Login or Register
Decware Audio Forums
12/16/17 at 13:11:12 





 



Pages: 1
Send Topic Print
ZMA harmonics (Read 4961 times)
Leigh
Verified Member
**




Posts: 7
ZMA harmonics
01/01/17 at 00:20:15
 
I am the owner of one of these lovely ZMA amps. I was poking around the forum and found the video where Steve goes over biasing the power tubes for the ZMA and also looks at the harmonic output of the amp by feeding it a 530 Hz sine wave and looking at the spectral output. It is probably located at the bottom right of the page as you are viewing this post.

However I believe that the what is on the screen does not match what is being said. In the video, the "first harmonic" is referred to as the first peak to the right of the fundamental frequency. However, that is the first overtone, which is the second harmonic, located around 1060 Hz. The second and third harmonics are about equal, although the third appears slightly more dominant. From from there on out, it's every other harmonic - the odd ones, not the even ones - that are dominant.

I have a attached a screenshot that labels the harmonics.

So unlike a "typical" push pull amplifier, where all of the even harmonics are suppressed and the odd harmonics decay slowly, the ZMA has a dominant second harmonic, in addition to an equally (if not stronger) dominant third harmonic, on top of all the subsequent decaying odd ones.

I find this interesting and it jives with my overall impressions of the amp. To my ear it is not a sweet sounding amp (like a single ended design dominated by rich even ordered harmonics).
Back to top
 

zma-spectrum.png
  IP Logged
Archie
Seasoned Member
****




Posts: 688
Re: ZMA harmonics
Reply #1 - 01/01/17 at 18:34:15
 
I looked back at the Torii IV product page where Steve talks about even ordered harmonics in a push-pull amp.  His, unlike typical push-pull amps that have no even ordered harmonics (his assertion), have even ordered harmonics.  I think the ZMA video shows that although I don't know the difference between an overtone and a harmonic.  On the Torri IV page he calls the spikes "echos."  Without the scale on the bottom of the graph it's hard to tell which spike is which.  I think, based on the Torii graph, the numbers would need to shift one to the right.

http://www.decware.com/newsite/TORII.htm
Back to top
 
« Last Edit: 01/01/17 at 18:35:48 by Archie »  
  IP Logged
Lonely Raven
Seasoned Member
****


Jack of all Trades,
Master of None

Posts: 2964
Re: ZMA harmonics
Reply #2 - 01/02/17 at 21:19:46
 

Interesting observation.

I remember when I first heard the ZMA at Decfest when it was debuted - I told Steve there was something going on harmonically I couldn't quite put my finger on...but it wasn't like single ended sweetness.

He looked at me strangely...probably because I heard what that graph is showing. LOL
Back to top
 
 
WWW Lonely Raven   IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 2634
Re: ZMA harmonics
Reply #3 - 01/03/17 at 16:57:53
 
Very interesting.

Ditto for me, harmonically I can't put my finger ear on it.....but it isn't single ended sweetness here. What it is though, is so damn goooood.
I can't, really I can't go back to low power/single ended..... .

Since I run my ZMA san's pre now:
to incorporate a little sweetness, I run my Mull's for input tubes and my Tele's for inverter's

for more of a straight shooter, I run my Ediswan's for inputs and my Tungsram PCC88's for inverter's

then, for flat line straight.....my Tungsram 6922's with either the Tung' PCC88's for inverter's or the stellar Telefunken's stay in for inverter's.

I tend to agree with Bascom King, about how good the Tungsram's are. However, the Mull's I have and the Edi's and Tele....trump them. With all due respect to Mr. King....he ought to hear them in a ZMA with my setup.  ;D



NOS Platinum Tubes from Upscale Audio/Kevin:

(Great Britain) Mullard 7308/E188CC ~  2 pair (both pair Cryogenic)
(Germany) Telefunken E88CC ~ 1 pair
(US/Great Britain) Ediswan CV2492/6922 ~ 2 pair (one pair Cryogenic)
(Hungary) Tungsram 6922/E88CC ~ 1 pair
(Hungary) Tungsram PCC88/7DJ8 ~ 1 pair.

From Cryoset:
(Russia) 6N23N/P-EB ~ 2 pair

(Russia) 6N23P's ~ 2 pair/came with ZMA.  

Back to top
 
« Last Edit: 01/03/17 at 18:28:09 by stone_of_tone »  

Sony as Transport
Illuminati D-60
Audio Alchemy DTI-Pro
Audio Magic Mystic Reference I2S
Audio Alchemy DDE 3.0
Kimber Select 1030
Zen Select #76
Kimber Select 3033
Polk Audio LS-90
Tri-config/TipToes & Vibropods underneath Speakers
360 degree Rm Treats
  IP Logged
Matchstikman
Seasoned Member
****




Posts: 643
Re: ZMA harmonics
Reply #4 - 01/03/17 at 21:57:10
 
Stone, I understand not wanting to go back to low power/single ended amps.  However, I think they have a place in the home.  For me, those late night listening sessions or as a desktop setup they work fine and are even preferred.

When I've tried to use a low power/single ended amp for big sound it didn't always go the way I wanted.  The 2 watters were tough but they still fell short of what was demanded.  

I came to this conclustion after I went to the Van Alstine that had much more muscle.  I can't go back to what I had before in the living room.  Maybe others have a setup that does fine but I don't.
Back to top
 
 
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 2634
Re: ZMA harmonics
Reply #5 - 01/04/17 at 17:19:19
 
Yes, I have a big muscle Amp in the living room. Wish it was a Van Alstine. I need it to drive my Polk SRS SDA 1.2's. My Vinyl Rig resides here too. A modest ProJect Debut Carbon.

Listening Room is a whole other kettle of fish!

Anyway, I'm not knocking the little guys of 2 watts or 5.8 or 20 to 25 for that matter. I recently had a Carina in (great Amp) and a Rachael on the way. But, I had to scratch my head, and stick with what I really want out of my Listening Room and future Decware purchases. I have the Pill - S's coming for example (for my DVR/Sat Radio/living room and to experiment in my Listening Room). I owned my SE84CS for 13 years and enjoyed every minute of it. However, the Speaker's I love and modified are at 91 to 93db SPL @ 1watt/1meter and I need a little more head room for these/my Adagio's. The ZMA with them is heaven.

However, I might have Steve's new Omega in this time next year. I always keep an open mind about running 2 watts again; (but, this time with: /channel/95 to 97db SPL/1watt/1meter-speakers)! Or, better yet, road trip to Peoria by appt. and hear them this summer and MAYBE, I want them for my ZMA, even though you can fill a big room with them with 2 watts/channel.
Back to top
 
« Last Edit: 01/05/17 at 01:35:49 by stone_of_tone »  

Sony as Transport
Illuminati D-60
Audio Alchemy DTI-Pro
Audio Magic Mystic Reference I2S
Audio Alchemy DDE 3.0
Kimber Select 1030
Zen Select #76
Kimber Select 3033
Polk Audio LS-90
Tri-config/TipToes & Vibropods underneath Speakers
360 degree Rm Treats
  IP Logged
Lonely Raven
Seasoned Member
****


Jack of all Trades,
Master of None

Posts: 2964
Re: ZMA harmonics
Reply #6 - 01/10/17 at 15:17:30
 

I'm dropping off my original Zen amp with Steve to have him UFO it. I don't use it at all since getting the ZMA; the big amp just does everything so well...but I'm hoping a little Ultralinear action in a small (10' x 11' x 8') dedicated room might bring some 3d magic back into my life.

But yeah, ZMA does what I need, and lets me focus on source and room.
Back to top
 
 
WWW Lonely Raven   IP Logged
Steve Deckert
Administrator
*****


If the 1st watt
sucks why continue?

Posts: 3106
Re: ZMA harmonics
Reply #7 - 01/12/17 at 01:33:50
 
Hi Leigh,

Welcome to the forum!  In your post what you have labeled as no.1  in the picture (zma-spectrum.png), is actually the fundamental tone, not the first harmonic Smiley


Steve
Back to top
 
 
WWW   IP Logged
Leigh
Verified Member
**




Posts: 7
Re: ZMA harmonics
Reply #8 - 01/14/17 at 22:43:01
 
Hi Steve!!

The first harmonic as I understand it refers to the fundamental tone (https://en.wikipedia.org/wiki/Fundamental_frequency) - that's how I was taught/learned. 1 * fundamental tone = first harmonic. 2 * fundamental tone = second harmonic, etc. I.e., the second harmonic is usually considered an octave above the fundamental tone, right? Wouldn't that make the 1st harmonic the fundamental tone? Even harmonics are even multiples of the fundamental tone, right?

From Wikipedia: "The fundamental frequency is considered the first harmonic and the first partial. The numbering of the partials and harmonics is then usually the same; the second partial is the second harmonic, etc"

Not trying to be difficult; trying to understand.

Edit: Here's a Stereophile discussion comparing small amounts of 7th order harmonic distortion to large amounts of 2nd, with spectra: http://www.stereophile.com/content/listening-146-page-2
Back to top
 
« Last Edit: 01/14/17 at 22:51:38 by Leigh »  
  IP Logged
Archie
Seasoned Member
****




Posts: 688
Re: ZMA harmonics
Reply #9 - 01/15/17 at 01:41:20
 
Quote:
From Wikipedia: "The fundamental frequency is considered the first harmonic and the first partial. The numbering of the partials and harmonics is then usually the same; the second partial is the second harmonic, etc"


In vibration terms there is input and response.  Knock on something mechanical and it will vibrate depending on its first or fundamental, frequency then its second, third, etc.  If sound is analogous, and I don't see why it wouldn't be, the input tone wouldn't be a harmonic, first, second or otherwise.  First Fundamental Frequency is NOT the same as the fundamental tone, which is the input tone, but rather is the lowest or first resonant frequency, of the system.

This seems consistent with the Wikipedia quote you posted.  Steve is correct.


Edit: Quote:
First Fundamental Frequency is NOT the same as the fundamental tone, which is the input tone
 I may be mistaken in this statement.  Forcing function and response is confusing and I never should have made a declarative statement.
Back to top
 
« Last Edit: 01/15/17 at 19:44:07 by Archie »  
  IP Logged
Archie
Seasoned Member
****




Posts: 688
Re: ZMA harmonics
Reply #10 - 01/15/17 at 19:41:23
 
There seems to be a semantic confusion going on here.  I keep referring back to the Torii IV page where this is also discussed.  I think that page makes things clearer and seems consistent with the video that shows both even and odd harmonics present in the ZMA response.  According to the Torii page, a "typical" push pull amp suppresses even ordered harmonics.

Is the basic conclusion at issue here or just definitions?  I had originally asked Steve, in another thread, whether the ZMA preserved even ordered harmonics like the Torrii (and musical instruments) and the video was part of the reply.
Back to top
 
 
  IP Logged
Dave1210
Seasoned Member
****




Posts: 924
Re: ZMA harmonics
Reply #11 - 01/20/17 at 11:14:52
 
This was from Paul's Post today and is relevant to this thread...

http://www.psaudio.com/pauls-posts/do-measurements-matter/

Back to top
 
 
  IP Logged
Dave1210
Seasoned Member
****




Posts: 924
Re: ZMA harmonics
Reply #12 - 01/22/17 at 11:46:51
 
Back to top
 
 
  IP Logged
Donnie
Seasoned Member
****


Why does it hurt
when I pee?

Posts: 1114
Re: ZMA harmonics
Reply #13 - 01/22/17 at 15:24:39
 
Back to top
 
 

Owner of the infamous RED TORII
  IP Logged
Archie
Seasoned Member
****




Posts: 688
Re: ZMA harmonics
Reply #14 - 01/22/17 at 18:51:29
 
It's funny that in that link, http://www.psaudio.com/pauls-posts/do-measurements-matter/, there was the same confusion between Fundamental Tone and First Harmonic.  If I read the post correctly, Paul uses the same terminology as Steve in his Reply #7 above.

Somewhere there is a White Paper by Steve that, I think, says something very similar about THD as what Paul says in this link:  http://www.psaudio.com/pauls-posts/what-matters/  I think Steve even went so far as to write that given a room full of cheap amplifiers, taking the one with the worst THD would likely result in the best sounding amp.
Back to top
 
 
  IP Logged
Dave1210
Seasoned Member
****




Posts: 924
Re: ZMA harmonics
Reply #15 - 01/22/17 at 21:53:30
 
The fundamental tone is as Steve indicated (labeled as 1 in Leigh's graph above).  F=530Hz.  

The first harmonic in the graph above (labeled as 2) is an even order harmonic. Fundamental x2 = 1060Hz.  

The second harmonic in the graph above (labeled as 3) is an odd ordered harmonic. Fundamental x3 = 1590 Hz.

The confusion comes from the video where the second harmonic (@1590Hz) is mistakenly referred to as an even order harmonic, when in fact it is an odd order harmonic.  As Leigh stated, even order harmonics are present, but the odd order harmonics are slightly dominant.  
Back to top
 
 
  IP Logged
Dave1210
Seasoned Member
****




Posts: 924
Re: ZMA harmonics
Reply #16 - 01/23/17 at 01:06:59
 
Lin...the first graph in Paul's post is correct and he admitted that the second graph was labeled incorrectly.

For me, the discussion is even vs. odd harmonics, not what constitutes the first harmonic per se.  For example, the first harmonic could be even or odd depending on the amp (Steve showed that clearly on the Torii page).  That said, I don't think you are disagreeing that the even harmonic of a 530Hz tone is 1060Hz, or are you?

Leigh is correct in that odd, not even order harmonics slightly dominate the harmonic distortion spectra of the ZMA.   I thought you also agreed with Leigh's conclusion, but I can't seem to find your post any longer...

Back to top
 
« Last Edit: 01/23/17 at 01:21:49 by Dave1210 »  
  IP Logged
Steve Deckert
Administrator
*****


If the 1st watt
sucks why continue?

Posts: 3106
Re: ZMA harmonics
Reply #17 - 01/24/17 at 04:14:28
 
Quote:
The confusion comes from the video where the second harmonic (@1590Hz) is mistakenly referred to as an even order harmonic, when in fact it is an odd order harmonic.  As Leigh stated, even order harmonics are present, but the odd order harmonics are slightly dominant.


I reviewed the video and you are right, I apologize for starting so much confusion!!  I have edited the video and am grateful for having it pointed out to me!  

I have to agree with Paul at PS Audio that the harmonic distortion of the amplifier is dwarfed by most loudspeakers, and is in my experience pretty far down there in the overall voicing of an amplifier.  The main thing I've learned is that pure odd order harmonics, especially higher ones, appear to short me out a little bit even though I don't consciously hear them at my normal listening volumes.  One can speculate that adding the even order harmonics into the mix makes a new soup of the odd order and everything becomes more palpable... but the only way I know to do that is with tubes which bring so many contrasts to the table that the comparison can't really be made.  I mean, giant glass high voltage fire bottles vs. tiny pieces of flat sand running at 1/10th the voltage are apples and oranges from any reasonable perspective.

When you look at harmonic distortion in an amplifier, you have an overwhelming urge, if not need to see it gone or reduced as much as possible. You can't help it.  In my early days, while developing the 2 watt Zen Triode amplifier, I was on my 30th revision on one amp and 29th revision on the other one when things got really good. I then made the 29 match 30 which was the better of the two, and lived with the matched pair for a few months.

I then started to wonder... got the scope out and measured the amplifier's power, distortion and frequency balance and in so doing got too close to the event horizon when it happened! I got sucked in the black hole of specificationism. Two days later, the amplifier had 50% more power, and half the distortion and I was pretty firkin proud of myself and took the now perfect amplifier into the listening room and it sounded like complete shit. It's spirit was crushed, dimensionality destroyed, transparency became your enemy not your friend, and two years of voicing gone.  

This is why you always build two of everything during development. And after that experience I didn't look at any of my amplifiers on the scope until after the amp was done, production samples made, photos shot, web page done, price set, and at least two or three sold. I had to be committed to it 110% so there was no possibility of changing anything. Then and only then would I look at the scope and learn to deal with and digest what I saw from a different perspective which was and still is hard to do.

I would venture to guess that on a production product there are not too many engineers on the planet that could or would even consider designing and building an amplifier without his computer, or scope. This is exactly why despite the overwhelming number of competitors that we have, so few are really even competing. It takes balls to trust your ears in this psychotic hobby where everything is subjective and placebo driven. If it weren't so, no one would care what audio gear looked like on paper. It is this basic element of the hi-end hobby that drives the publishing of specifications in an attempt to make sense of it all and be able to predict what might sound better, and of course we already know it does not.

Steve  :)


Back to top
 
« Last Edit: 01/25/17 at 02:29:07 by Steve Deckert »  
WWW   IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 2634
Re: ZMA harmonics
Reply #18 - 01/24/17 at 17:57:45
 
WOW, so well put (Steve).
"This is exactly why despite the overwhelming number of competitors that we have, so few are really even competing. It takes balls to trust your ears in this psychotic hobby where everything is subjective and placebo driven".

Celebrated my 3rd year completion this past Sunday with your Zen Mystery Amplifier masterpiece.

Jan 22/2014 ~ Jan 22/2017.
Back to top
 
 

Sony as Transport
Illuminati D-60
Audio Alchemy DTI-Pro
Audio Magic Mystic Reference I2S
Audio Alchemy DDE 3.0
Kimber Select 1030
Zen Select #76
Kimber Select 3033
Polk Audio LS-90
Tri-config/TipToes & Vibropods underneath Speakers
360 degree Rm Treats
  IP Logged
Archie
Seasoned Member
****




Posts: 688
Re: ZMA harmonics
Reply #19 - 01/24/17 at 18:04:44
 
It's kind of weird to have a "faith based" audio system but early on I decided to trust Steve and go Decware all the way.  It's a bit like climbing Mount Everest with an experienced guide!   Smiley
Back to top
 
 
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 2634
Re: ZMA harmonics
Reply #20 - 01/24/17 at 18:07:12
 
Yes Archie, the 2nd to last paragraph of Steve's is particularly powerful (110% committed).

I remember like it was yesterday....talking to Steve on the phone in May of 2001. When I got my SE84CS to my Listening Room and my jaw dropped......"I got it".....and the number's game was over for me, then and there.
Back to top
 
« Last Edit: 01/24/17 at 18:08:29 by stone_of_tone »  

Sony as Transport
Illuminati D-60
Audio Alchemy DTI-Pro
Audio Magic Mystic Reference I2S
Audio Alchemy DDE 3.0
Kimber Select 1030
Zen Select #76
Kimber Select 3033
Polk Audio LS-90
Tri-config/TipToes & Vibropods underneath Speakers
360 degree Rm Treats
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. D*ck

Posts: 13032
Re: ZMA harmonics
Reply #21 - 01/24/17 at 18:21:08
 
It was early '98 for me and the 27th amp Steve built. I gave up on the audio press soon afterwards and it's been Decware pre-amplfication, amplification and speakers since (didn't like the sources or cabling enough to keep, but it's good stuff).

These are lifetime components that deliver musical satisfaction.

Back to top
 
 

HR-1,ZP3,ZTPRE,Torii MkIII,ZBIT,ZROCK2,Taboo MkIV;PS Audio:Soloist SE,DMP+DSD,P10,PowerBases,AC-12 pcs,Mapleshade:Dbl Helix+,SamsonV2+V3;CambrAudi CXU;Rega RP3,TTPSU,Groovetracer upgrades,Exact2;VooDoo Cremona +Amati,Iso-Pods;MD90-T SE tuner,Oppo PM-1,Audeze LCD-2
  IP Logged
Leigh
Verified Member
**




Posts: 7
Re: ZMA harmonics
Reply #22 - 01/29/17 at 17:59:57
 
Quote:
It takes balls to trust your ears in this psychotic hobby where everything is subjective and placebo driven.

Indeed and the numbers never tell the whole story, it's taken me years to really understand this on an experiential level. My experience is, if the numbers are bad, it will sound bad, but if the numbers are good, it might sound good. I think in the case of good numbers and bad sound, it's about not measuring the right thing.

The ZMA brings major happiness to my life, what more need be said! And I haven't even started tube rolling yet... I probably would have if it didn't sound so good with the tubes it shipped with. I have a matched quad of NOS RFT EL34s that keep sending me expectant vibes.
Back to top
 
 
  IP Logged
Archie
Seasoned Member
****




Posts: 688
Re: ZMA harmonics
Reply #23 - 01/29/17 at 18:29:00
 
Quote:
I have a matched quad of NOS RFT EL34s that keep sending me expectant vibes.


I'm enjoying the Tungsol EL34s that I bought from lLance.  I'm not a big fan of KT66s in my ZMA -- with my analogue front end anyway.
Back to top
 
 
  IP Logged
mark58
Seasoned Member
****




Posts: 4621
Re: ZMA harmonics
Reply #24 - 01/29/17 at 19:08:35
 
Leigh, please put in those RFTs...they are my favorite power tubes for my Torii MK IV.  I would like to get your take in the ZMA.  Mark.
Back to top
 
 

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;
The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare
  IP Logged
Leigh
Verified Member
**




Posts: 7
Re: ZMA harmonics
Reply #25 - 03/11/17 at 15:59:26
 
Quote:
Leigh, please put in those RFTs...they are my favorite power tubes for my Torii MK IV.  I would like to get your take in the ZMA.  Mark


So this is from memory, as I switched back to the stock KT66's after a couple of weeks (about 8 hours total listening time). The RFT EL34's biased easily. I biased them at 50 mA. The word I kept coming back to to describe the sound was "brown" - it was a darker sound, with that spooky EL34 midrange, but not as lively as with the KT66's. The EL34s made ZMA sound more like a "tube amp" whereas the KT66's have it sound more like a "really good clean hifi amp".

I am sure if I had spent more time with the EL34s it would have begun to sound more normal to me, but I kept longing for the clearer more "sparkly" sound of the KT66s, so I swapped them out.

The soundstaging and effortless power of the ZMA was similar between the different tubes, FYI. It was an interesting exercise but I'll probably be sticking with KT66's for this amp.
Back to top
 
 
  IP Logged
mark58
Seasoned Member
****




Posts: 4621
Re: ZMA harmonics
Reply #26 - 03/11/17 at 16:29:33
 
Thanks for your impressions.  So when are you going to sell me the RFT EL 34's?  Mark.
Back to top
 
 

"The man that hath no music in himself, nor is not moved with the concord of sweet sounds, is fit for treasons, deceptions, and spoils;
The motions of his spirit are dull as night and his affections dark as Hell. Let no such man be trusted." William Shakespeare
  IP Logged
Pages: 1
Send Topic Print