F6 Amplifier - Page 186 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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
Reply
 
Thread Tools Search this Thread
Old 14th September 2012, 05:46 PM   #1851
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Quote:
Originally Posted by lhquam View Post
Told me what? Do not forget that high values of Rswip1 and Rswip2 mean higher output impedance and lower damping factor. There is a tradeoff between lower THD and lower Zo. Also consider that small "tweaks" to the relative values of Rswip1 and Rswip2 are comparable to minor adjustments to Rs to correct for transconductance differences of the output FETs and reduce 2nd harmonic.
Forget pot and do same thing with different Rs and cap positioning. Both caps don't have to be in same place. All things affect everything and just simmig only goes so far. Listen to cap above on both.( I know you have it that way). Now take upper cap and connect bellow top Rs. Listen and then test not only THD but also harmonic breakdown. Shape the sound man.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 14th September 2012, 06:01 PM   #1852
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
You cannot get the 2nd harmonic minimum with just the above/below combos unless you try many many combinations of Rs-above and Rs-below. The variable adjustment greatly simplifies things and does not require readjustment of the DC bias.
Quote:
Originally Posted by buzzforb View Post
Forget pot and do same thing with different Rs and cap positioning. Both caps don't have to be in same place. All things affect everything and just simmig only goes so far. Listen to cap above on both.( I know you have it that way). Now take upper cap and connect bellow top Rs. Listen and then test not only THD but also harmonic breakdown. Shape the sound man.
  Reply With Quote
Old 14th September 2012, 06:39 PM   #1853
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by buzzforb View Post
.... Shape the sound man.



my man Buzz ...... that's good enough for sig
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 14th September 2012, 09:25 PM   #1854
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
Perhaps my post with the THD vs Freq plots wasn't clear. These were NOT simulations, they were measurements of the actual PCB using the pots.

Quote:
Originally Posted by buzzforb View Post
Forget pot and do same thing with different Rs and cap positioning. Both caps don't have to be in same place. All things affect everything and just simmig only goes so far. Listen to cap above on both.( I know you have it that way). Now take upper cap and connect bellow top Rs. Listen and then test not only THD but also harmonic breakdown. Shape the sound man.
  Reply With Quote
Old 14th September 2012, 09:29 PM   #1855
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
I just ran some measurements....
that was pretty clear
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 14th September 2012, 09:39 PM   #1856
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Ilquam,
You are the man. You have put forward a tremendous effort and have offered lots of information that has been helpful, but I am weird. I want to know what you hear.
What differences you perceive, and why you think they are occurring. I am trying to take advantage of your knowledge to help shape my sound, but i cant do that with measurement, solely. I am perhaps asking for the wrong thing(my ignorance again), as I think i want the frequency sweep showing the breakdown of the harmonic structure. Simple version is seen in 3rd pic of this link.

Using FFT spectrum analysers for audio amplifier design
__________________
...Shape the sound , Man!
  Reply With Quote
Old 14th September 2012, 09:40 PM   #1857
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
ZM: How much more performance-wise can be squeezed out of the F6 Conceptual Schematic beyond what I am seeing? How will I know when I am getting close?

Quote:
Originally Posted by Zen Mod View Post
that was pretty clear
  Reply With Quote
Old 14th September 2012, 09:51 PM   #1858
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Quote:
Originally Posted by Zen Mod View Post
Pa is having fun

zillion of posts ,based on teaser
Perhaps in the future I will let you guys do all the work.

In the meantime, I will suggest that you have taken it about as far as
it will go, now that you are just down the choices of the Rs values.

I'm at the coast finishing the F6 article up, and no doubt you will be
pleased with yourselves when you see it.

  Reply With Quote
Old 14th September 2012, 10:18 PM   #1859
willamp is offline willamp  United States
diyAudio Member
 
willamp's Avatar
 
Join Date: Dec 2011
Location: Austin, Texas
Quote:
Originally Posted by Nelson Pass View Post
Perhaps in the future I will let you guys do all the work.

In the meantime, I will suggest that you have taken it about as far as
it will go, now that you are just down the choices of the Rs values.

I'm at the coast finishing the F6 article up, and no doubt you will be
pleased with yourselves when you see it.

I have been watching this whole affair since it started waiting for a working schematic from Mr Pass. And, at the same time being amazed by the talents of this community. I don't have the skills to go from the teaser to working circuits myself but I have tried to follow all the great minds posting their thoughts here. Kudos to all who have elevated a simple audio transformer to the celebrity status of being the centerpiece of over 1800 posts.

While I was waiting I've started collecting parts for an F4 to join my F5. Will I be able to complete it before I'm compelled to collect the parts for an F6?...time will tell.
  Reply With Quote
Old 14th September 2012, 10:23 PM   #1860
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by Nelson Pass View Post
.....


proud Pa

Attached Images
File Type: jpg St.-Stephen.jpg (27.8 KB, 229 views)
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New F6 diy coming soon ? Nounours18200 Pass Labs 37 31st August 2012 04:35 PM
Hi Vi F6 box ioro Multi-Way 4 15th April 2012 08:27 PM
Whats happening with F6? jugoslavija Pass Labs 1 1st November 2011 07:39 AM
Hi-Vi F6 kkosiba Multi-Way 14 9th November 2007 08:38 AM
F6 traw Pass Labs 7 2nd November 2007 07:09 PM


New To Site? Need Help?

All times are GMT. The time now is 04:21 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2