2SJ28 Vfet SE Amplifier - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 28th December 2009, 03:08 PM   #11
mos57 is offline mos57  Italy
diyAudio Member
mos57's Avatar
Join Date: Apr 2006
Location: Catanzaro - Italy
My point of view is quite different: in SE circuit we can better evaluate the intrinsic component's character. In PP there are partially cancellations for some aspects or superimposition for others.

Is SE is easy to view with a scope the lower distortion of IRF 530 against IRF540 or 240: so why we not choice always the 530 i.e or better L-Mos or V-fet?
Because, on the other hand, for musical pleasure is not only important distortion but also other things as low output impedance for example, and in this way IRF540/240 are better than 530.
Whith its higher trasconductance/lower output impedance IRF540/240 are capable of better bass quality with better damping factor (read faster bass) than IRF530. Then, if not need high power it isn't need excessive voltage swing, the bigger IRF240/540 can become the first choice for the following: the difference in distortion becomes also little meanwhile the bass response remain much better than 530.
So the advantage of use IRF540/240 is to have bass much impressive and controlled and a sound more warm (ZEN amp).

But what about the high ends and details? Pheraps the little devices are better? SURE.

But more bigger devices are better always? No.
When devices is capable to manage very high current, then it become linear at very high quiescent current, value impossible in the field of linear amplification (10-20A). In the same time the parasitic capacitors (especially the input cap) becomes very relevant and tend to close the bandwith without high freq. tones.

So at the end not exist one components better for all.
I tend to have a compromise for these opposite necessity: from my experience in audio world, i prefer unipolar devices with Id from 7 to 15 A and low/medium Gm, low Rout.

  Reply With Quote


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
Sony Vfet housing Solid State 26 26th January 2014 03:38 AM
Successors for V-FET SONY-Yamaha-TOKIN 2SJ28, 2SJ18/2SK60, 2SJ26/2SK76 and 2SK180 tiefbassuebertr Solid State 41 27th February 2012 04:07 PM
Sony TA-N7B VFET Help!! gpdavis2 Solid State 16 24th October 2009 01:20 PM

New To Site? Need Help?

All times are GMT. The time now is 12:29 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2