F5 power amplifier - Page 1140 - 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 15th December 2011, 07:20 AM   #11391
diyAudio Member
 
bobodioulasso's Avatar
 
Join Date: May 2008
Quote:
Originally Posted by arche13 View Post
good evening

What should be the maximum output voltage for the power transformer can be used f5 a voltage greater than 18VAC as drawing on original NP
I think using a voltage between 18 and 24vc before rectification and filtering what should be the bias?
thank you all
Using V2 boards, you can build a 50w F5 using 2 outputs and a cascode.
2x25v transformer. (2x33v DC) Bias about 0,85A each output leg.
See diyaudio store and Cviller's blog.

Last edited by bobodioulasso; 15th December 2011 at 07:30 AM.
  Reply With Quote
Old 15th December 2011, 05:42 PM   #11392
diyAudio Member
 
Bksabath's Avatar
 
Join Date: Dec 2007
Quote:
Originally Posted by arche13 View Post
good evening

What should be the maximum output voltage for the power transformer can be used f5 a voltage greater than 18VAC as drawing on original NP
I think using a voltage between 18 and 24vc before rectification and filtering what should be the bias?
thank you all

My 2 cents
As hi as your heat sinks alowd.

Papa said <I wold not push big ones (TO247) at more than 50 W each >
I had my F5 at 2.8 A (1.4 A each) and 35V or there about rails for a while with no problems.

Just make shure Junction temperature dont go over 75 C then is just heath sink size and how much time and money you invest in the thermal coupling

Red Kerafol heat spreaders clamping methode.

Papa also said that < at higher voltagge they sound better>

I have not made standard F5 to compare as with for 4 Homs speakers I went for big hammer first.

Just get speaker protection for peace of mind.
  Reply With Quote
Old 15th December 2011, 07:46 PM   #11393
diyAudio Member
 
triode_al's Avatar
 
Join Date: May 2004
Location: Westland
Blog Entries: 1
Quote:
Originally Posted by arche13 View Post
Good evening

Which has to be the maximal tension of exit(release) for the transformer of food(supply) of f5 can one use a tension superior(higher education) in 18vac such as on original plan.
I plan to use a tension enter 18 and 24vc before recovery and filtering what has to be the way?
Thanks to all
Bon soir. Not nearly as bad translation as chinglish! At least you give food for thought.
__________________
DAC TDA1541 S1; Kondo post-I/V filter; MC30-Super --> two stage RIAA; Pre: Kaneda ; F5 ; 300B PP ; ESL 57
  Reply With Quote
Old 16th December 2011, 06:02 AM   #11394
arche13 is offline arche13  France
diyAudio Member
 
Join Date: Jan 2009
transformers 300VA delivers 21.6 vac piece can be used with f5 base?
  Reply With Quote
Old 16th December 2011, 09:41 AM   #11395
diyAudio Member
 
bobodioulasso's Avatar
 
Join Date: May 2008
What is writen on the transformer?
Did you measure 21,6 unloaded?
If so, the transformers are 20v ac.

It's Ok for an F5.
Just set the bias to about 1,2A instead of 1,3A to keep dissipation right.
  Reply With Quote
Old 16th December 2011, 09:39 PM   #11396
diyAudio Member
 
luvdunhill's Avatar
 
Join Date: Jul 2006
Quote:
Originally Posted by jackinnj View Post
Gain of the first stage is P1/[(1/gm)+Rs] and is nominally 10, so adding 50R is going to get a bit closer to 10X from the original. You don't have to add P3 -- you can parallel values against one or the other against R1/R2 (Refdes from the original schematic).

I experimented with this and it doesn't take much tweeking of P3 to lower the THD. I'll state again, however, that right out of the box the F5 THD% is 0.006% to 0.008% @1W into 8R

As there's still a bit of water in the workshop, I won't be able to demonstrate with a chart for a while!
So, at what point when increasing the feedback resistors, say from 2x100 to 2x200 do you have to start decreasing the 10 ohm degeneration resistors or moving up to V grade JFETs? How high of gain have people experimented with? I realize it will no longer be a F5, but I'd like to take this chance and learn a bit more about the inner workings of this circuit.
  Reply With Quote
Old 17th December 2011, 12:53 PM   #11397
Pistu is offline Pistu  Italy
diyAudio Member
 
Join Date: Dec 2011
Location: Genova
best wishes for a speedy recovery! Merry Christmas and Happy New Year.😉
Massimo Bianchi🎅🎅🎅
  Reply With Quote
Old 17th December 2011, 01:37 PM   #11398
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Significate che qualcuno è malato ?
__________________
The buck stops Here
  Reply With Quote
Old 17th December 2011, 02:52 PM   #11399
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
tutti qui sono ....... genere di

__________________
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 17th December 2011, 03:15 PM   #11400
Pistu is offline Pistu  Italy
diyAudio Member
 
Join Date: Dec 2011
Location: Genova
I am sorry ... I did not read the date of the post of Nelson. Merry Christmas
Massimo
  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 11:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 06:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 11:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 09:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 05:06 PM


New To Site? Need Help?

All times are GMT. The time now is 06:31 AM.


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