F5 power amplifier - Page 130 - 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 25th June 2008, 12:54 AM   #1291
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally posted by Ed LaFontaine


Mongo is a scientist
A sad week in that Harvey "Hedley" Korman passed away.

"Work, work, work..."

or, from the History of The World Part I "Hump or Death"

my new motto "It's good to be the King".
  Reply With Quote
Old 25th June 2008, 01:36 AM   #1292
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
If you blow out the ZTX450/550's it will oscillate (at least mine did)-- I replaced them and rebiased the amplifier and everything is OK.
  Reply With Quote
Old 25th June 2008, 03:10 AM   #1293
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
And George Carlin.

Interestingly, I get a little lower distortion with the bipolars sitting
in there as limiters. The very slight non-linearity they offer is in
opposition to the natural distortion of the circuit, giving a little 3rd
harmonic cancellation.



And here's what the sun looks like through all the smoke from the
surrounding forest fires:
Attached Images
File Type: jpg smoky sun sm.jpg (65.1 KB, 1965 views)
  Reply With Quote
Old 25th June 2008, 03:43 AM   #1294
diyAudio Member
 
MEGA_amp's Avatar
 
Join Date: Oct 2003
Location: CT
PassDiy .....sweet facelift!!


Quote:
And here's what the sun looks like through all the smoke from the surrounding forest fires:
Hey, if there's any danger to your property, I know of a great safe place you can send everything
  Reply With Quote
Old 25th June 2008, 03:59 AM   #1295
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
> For the first variant see attachment,

I could not see any attachment for 1st & 2nd variant ....



Patrick
  Reply With Quote
Old 25th June 2008, 03:17 PM   #1296
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
Default Power supply for F5

Almost done with my power supply. I put together a little Picasa Album of the build and if you are a super noob, like me, this might be helpful. If I goofed anything please let me know guys.
Uriah
http://picasaweb.google.com/udailey/F5PowerSupplyBuild
  Reply With Quote
Old 25th June 2008, 07:27 PM   #1297
diyAudio Member
 
Join Date: Apr 2006
Location: Dallas, Texas
Quote:
Originally posted by Nelson Pass

Interestingly, I get a little lower distortion with the bipolars sitting
in there as limiters. The very slight non-linearity they offer is in
opposition to the natural distortion of the circuit, giving a little 3rd
harmonic cancellation.
Well that is facinating information (well, at least to a newbe like
me)! In my spice simulations, the current limiting section of the
circuit _adds_ in the ballpark of an order of magnitude of THD
(even when the output is no where close to where the transistors
start conduction).

If one could generalize, how much do the simulations vary from
the real thing?

thanks,
Robert
  Reply With Quote
Old 25th June 2008, 08:00 PM   #1298
diyAudio Member
 
Join Date: Jan 2005
Location: missouri
i bought some toshiba 2sk170bl and 2sj74bl from ampslab-do i have to match the ones i put in a F5? and could someone steer me to an article on how to do it ? thanks bubba
  Reply With Quote
Old 25th June 2008, 08:30 PM   #1299
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Quote:
Originally posted by audiorob


Well that is facinating information (well, at least to a newbe like
me)! In my spice simulations, the current limiting section of the
circuit _adds_ in the ballpark of an order of magnitude of THD
(even when the output is no where close to where the transistors
start conduction).

If one could generalize, how much do the simulations vary from
the real thing?

thanks,
Robert
With the thermal comp in my F5 I get THD+N% a little over 0.003% @1W. No trimming of the JFET source resistors either.
  Reply With Quote
Old 25th June 2008, 09:50 PM   #1300
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Quote:
Originally posted by audiorob
If one could generalize, how much do the simulations vary from
the real thing?
A lot depends on the quality of models. The Mosfet models are
understood to be the least accurate. I have seen up to 10 to 1
variations in distortion depending on the real Mosfet and the
model.

I have seen simulations from over in the Solid State forum where
a constant Vds JFET yielded pure 2nd harmonic, but on my bench
I have not been able to duplicate that - there is always some 3rd.

I personally do not depend on simulations to predict distortion
in circuits. I prefer to build them and see, although it is also
interesting to compare the results to sims.

BTW, I got about .003% on my first channel, and having built a
few now, it appears that the simple majority of them hit this
without tweaking.
  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
Rockford Fosgate Power 20001 bd amplifier power rating?? pachoorion Car Audio 8 8th May 2011 10:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 05:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 10:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 08:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 04:06 PM


New To Site? Need Help?

All times are GMT. The time now is 01:47 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