Power amp output - BJT or MosFET? - Page 3 - 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
Thread Tools Search this Thread
Old 25th April 2004, 04:58 AM   #21
diyAudio Member
slowhands's Avatar
Join Date: Feb 2004
Location: Silicon Valley
Default Re: About vertical and lateral mosfet

Originally posted by lumanauw
I have built amp with K1058 pairs, it is lateral mosfet. In the manufacturer's datasheet it is definitely for audio use. But why I feel that with vertical mosfet (IRF) the sound just seems tobe have more character?
There is also controvercy about a certain device is good or bad for audio, like 4558 opamp.
Is it if a device is said for audio it is not automaticly that it will sound good?
The laterals are inferior for switching, compared to vertical MOSFETs. Their on resistance is too high, dissipation capability and currents too low. But they have the wonderful ability to share current in parallel, and avoid thermal runaway, for the simple reason that their transconductance decreases with temperature. This makes them ideal for audio use.

The main reason they have survived as a product is continued demand in the audio market. It is questionable whether there is enough demand to ensure long term availability from the manufacturers. The major player, Hitachi, has transferred its discrete semiconductor manufacturing to Renesas, a joint venture company (with Mitsubishi). Toshiba supplies a few parts, but is rumored to be ending production. There are several boutique semiconductor makers who produce them, but I personally would not bet my company on them.

The vertical MOSFETs have higher transconductance, lower on resistance, and higher power capability, and with care can perform as well or better. They usually need to be matched for parallel operation, and need temperature compensating bias generators for reliable operation in audio amps.
  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
Best MOSFET for output stages millwood Solid State 151 11th July 2014 02:23 PM
Lateral MOSFET, How do I calculate power output synonymous Solid State 4 18th December 2007 07:54 AM
mosfet output conversion engel dela pena Solid State 15 13th October 2007 11:16 AM
power output calculations, rated power and required power output metebalci Tubes / Valves 7 22nd February 2004 06:49 PM
output mosfet driver lazy Solid State 5 30th March 2002 05:13 AM

New To Site? Need Help?

All times are GMT. The time now is 02:00 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