Anyone built this mosfet follower (or similar)? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 7th December 2009, 10:29 AM   #1
GregH2 is offline GregH2  Australia
diyAudio Member
 
GregH2's Avatar
 
Join Date: Oct 2009
Default Anyone built this mosfet follower (or similar)?

Hi All,

I'm thinking about building this circuit and using it with a valve preamp design I have sen that can supply a +/- 20v signal:

Project 83 - MOSFET Power Follower

Has anyone tried building one of these followers or something similar? Any comments on how it sounded? Any ideas, suggestions or improvements? I'd love to hear your thoughts.

Regards,

Greg.
  Reply With Quote
Old 7th December 2009, 10:49 AM   #2
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
distorsion is high with powermos without NFB, though this one is better
than Pass s ZEN...

regards,
  Reply With Quote
Old 7th December 2009, 11:02 AM   #3
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
forgot to add that if you stick to 36V, it s better to drive it with a
quality OPAMP, a NE5532 would be very fine and much better than the
discrete preamplifier provided you use it with no more than 20 db gain...

all da best,
  Reply With Quote
Old 7th December 2009, 04:55 PM   #4
diyAudio Member
 
Join Date: Sep 2004
Location: Göteborg
Taylor Source Follower

This is a good link about source-followers.
A Taylor source-follower can give twice the current to the speaker compared to Rod Elliots project 83.
__________________
We live in a horizontal world, why use vertical topologies???
  Reply With Quote
Old 7th December 2009, 07:32 PM   #5
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by wahab View Post
distorsion is high with powermos without NFB, though this one is better
than Pass s ZEN...
regards,
Source follower resp. power follower still have a large amount of serial NFB, therefore there are only a unity gain factor (actually a bit lower than "1")
  Reply With Quote
Old 7th December 2009, 07:42 PM   #6
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by swordfishy View Post
Hi All,

I'm thinking about building this circuit and using it with a valve preamp design I have sen that can supply a +/- 20v signal:

Project 83 - MOSFET Power Follower

Has anyone tried building one of these followers or something similar? Any comments on how it sounded? Any ideas, suggestions or improvements? I'd love to hear your thoughts.

Regards,

Greg.
I have build follow:
the project about
the Power Folllower
but modify to a unity gain preamp with 1A idle current and only 9V supply voltage (for undistorted +/-1,5Vss, for the user the best preamp on this planet)
and your suggested project, but with a sziklai modification of Parvel Macura for the upper MOSFET and 3,5A idle current by 22V supply voltage (sziklai means a current feedback pair = discrete IGBT, that content follow type: IRF510 and 2SA1216) ask Parvel Macura for schematic, because this isn't online currently.

Last edited by tiefbassuebertr; 7th December 2009 at 07:44 PM.
  Reply With Quote
Old 7th December 2009, 08:41 PM   #7
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Blog Entries: 2
Quote:
Originally Posted by swordfishy View Post
Hi All,

I'm thinking about building this circuit and using it with a valve preamp design I have sen that can supply a +/- 20v signal:

Project 83 - MOSFET Power Follower

Has anyone tried building one of these followers or something similar? Any comments on how it sounded? Any ideas, suggestions or improvements? I'd love to hear your thoughts.

Regards,

Greg.
sorry - I can't comment on the sound. But I think your idea sounds good and worth building. I think it makes sense to do the experiment with the Power Follower.
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 7th December 2009, 08:51 PM   #8
AKSA is offline AKSA  Australia
diyAudio Member
 
Join Date: Sep 2001
Location: Melbourne, Australia
I did an amp several years ago using a 6SL7 as voltage amp and a very similar output stage to Pavel's follower. All distortion was low order, and the sound was indeed wonderful. If you have never heard one of these amps - or indeed the Pass Zen which was seminal too - do yourself a favour and knock one up from junk box parts.

They sound absolutely transcendental, particularly good on jazz and vocals. IMHO they tend to fall down a little with orchestral music.

Hugh
__________________
Aspen Amplifiers P/L (Australia)
www.aksaonline.com
  Reply With Quote
Old 7th December 2009, 08:58 PM   #9
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Well said, Hugh. Still more controlled than the ZEN topology.
__________________
Pavel Macura
http://web.telecom.cz/macura/audiopage.html
  Reply With Quote
Old 7th December 2009, 09:14 PM   #10
AKSA is offline AKSA  Australia
diyAudio Member
 
Join Date: Sep 2001
Location: Melbourne, Australia
The Zen was my re-introduction to electronics after a 20 year lapse.

I would never criticise it - no one does more with less than Nelson Pass.

Hugh
__________________
Aspen Amplifiers P/L (Australia)
www.aksaonline.com
  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
anyone ever built a tube mixer similar to the RCA Living Stereo type?? ncdrawl Tubes / Valves 12 23rd October 2008 06:13 PM
Does anyone has mosfet PP power follower schematic? bogdan_borko Solid State 0 11th December 2005 08:37 PM
Has anybody built 6BG6 or similar OTL amp? rnx69 Tubes / Valves 2 14th April 2004 01:25 PM
Driving a MOSFET power follower RichardJones Pass Labs 19 22nd July 2002 02:02 PM
MOSFET Power Follower help RichardJones Solid State 0 28th January 2002 06:01 PM


New To Site? Need Help?

All times are GMT. The time now is 09:00 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