F5 Cascoded - an alternative for my interest in the Balanced F5 - Page 4 - 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 22nd January 2011, 07:50 PM   #31
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
Thx NYCOne. As I said there are things I left out. My description was a little biased towards only raising the rail voltage and choosing to cascode to protect the input and attempt to lower distortion. Many here are interested in pairs or triplets of output devices also. This would be necessary due to the increased power dissapation of a higher rail but, a convinient method to increase output power also. Trouble is, it takes more current to drive the extra xistor capacitances or the high frequency's will suffer. Cascoding the input JFETs can help in this case also. Raising the Iq of the input stage should help in this regard. If I maintain 8Vds on Q1,2, I can easily operate the first stage at 12.5mA instead of 5mA In this situation an acompanying change in the R3,4 to some lower value. This however may cause a problem with lower input stage gain. Multiple output transistors will however increas output stage gain. These tradoffs are very likely to cause a change in the sound?
__________________
"It was the perfect high end audio product: Exotic, inefficient, expensive, unavailable, and toxic." N.P.
  Reply With Quote
Old 22nd January 2011, 07:59 PM   #32
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by NYCOne View Post

It would save a lot of time if there is an answer.
maybe there is none
the cascode does nothing else than what its supposed to do, "sharing" the voltage
theres is nothing to hear
and thats what have been stated
it works, and is inaudible

flg, your evaluation is interesting
  Reply With Quote
Old 22nd January 2011, 08:48 PM   #33
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
maybe I should also note that it is your right as a member to ask questions

and it is also a member's right to decide for himself whether he wants to participate

but ofcourse it all works better when there are members showing interest in other projects than just their own
  Reply With Quote
Old 22nd January 2011, 09:58 PM   #34
Banned
 
Join Date: Nov 2006
Quote:
Originally Posted by flg View Post
These tradoffs are very likely to cause a change in the sound?
Change in sound is not necessarily a bad thing - Hence the reason for F1 to F5, as well as Aleph J, J2, M2, they all sound different.
It's ok to be different.
  Reply With Quote
Old 22nd January 2011, 10:14 PM   #35
Banned
 
Join Date: Nov 2006
Speaking of different.
How about this one?

Edit: I was too lazy to add the gate resistors
Attached Images
File Type: png Lateral output.png (63.7 KB, 371 views)

Last edited by Melon Head; 22nd January 2011 at 10:19 PM.
  Reply With Quote
Old 22nd January 2011, 11:03 PM   #36
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
and - what's benefit ?

instead of patch-work of existing amp , better use some small mosfets (TO220 ) as drivers , with adequate current
__________________
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 22nd January 2011, 11:46 PM   #37
Banned
 
Join Date: Nov 2006
Just maintaining the same voltage gain. IRFP240/9240 has higher transconductance than IRF610/9610

Yes you could use those as well as many others I am just lazy. Actually not lazy just don't have the time.

I have to get back to painting a pergola. See Ya
  Reply With Quote
Old 22nd January 2011, 11:50 PM   #38
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
2SJ76 ringing a bell ?

__________________
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 23rd January 2011, 12:17 AM   #39
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
are you talking Aleph design now, I wonder

actually there are IRF TO-220(AB) with quite high transconductance, if thats requested

http://docs-europe.electrocomponents...6b80dcb1be.pdf
http://docs-europe.electrocomponents...6b807910f2.pdf
http://docs-europe.electrocomponents...6b807910ff.pdf
http://docs-europe.electrocomponents...6b80dcb3ae.pdf
http://docs-europe.electrocomponents...6b807913d7.pdf
  Reply With Quote
Old 23rd January 2011, 12:24 AM   #40
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
no - I'm talking about MH's follower-ed F5, from post #35
__________________
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
Balanced F5 question NYCOne Pass Labs 1153 23rd February 2011 06:42 PM
F5 Williams Audio Pass Labs 9 11th June 2010 09:13 PM
I need Help with my F5.... rtate Pass Labs 15 1st December 2009 11:07 PM
Anybody help with F5? yammy1688 Pass Labs 2 28th October 2008 03:50 PM
Yet another variation on cascoded balanced line stage jwb Pass Labs 10 27th October 2002 05:22 PM


New To Site? Need Help?

All times are GMT. The time now is 06:59 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