Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

20watt amplifier
20watt amplifier
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 20th August 2011, 06:55 PM   #1
shreya is offline shreya  India
diyAudio Member
Join Date: Aug 2010
Location: Andhra Pradesh
Default 20watt amplifier

Could somebody provide a 20watt amplifier that works with 12v (Only transistor based not chip)
  Reply With Quote
Old 20th August 2011, 08:04 PM   #2
Bigun is offline Bigun  Canada
diyAudio Member
Bigun's Avatar
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire UK
20watt amplifier
power into a speaker is usually quoted rms and is calculated from P(rms) = (voltage * voltage) / (speaker impedance * 2)

So, if you have 12V and I assume that means +/- 6V peak to peak, less say 1V for drop across a power device (optimistic) then you have +/- 5V.

To get 20W rms you need a load impedance of less than 1 Ohm.

Seems like a tough call with most speakers - looks like you will need to increase the voltage.
"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 20th August 2011, 09:02 PM   #3
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
Join Date: Nov 2005
20watt amplifier
Jean Hiraga's Monster is 8watt, on 12V

you could use one of those car switch mode
converts 12V into higher voltage

41hz sells classD kits for 12V
  Reply With Quote
Old 20th August 2011, 09:32 PM   #4
john_ellis is offline john_ellis  United Kingdom
diyAudio Member
Join Date: Sep 2006
Two ways to do this, assuming you want to use standard 8 ohm speakers.
1. Use an old-fashioned transformer output stage. You will almost certainly need to wind a suitable transformer but the core size would be around 29 (EI100) or bigger depending on the frequency response you wanted
There are some companies that might wind the transformer(s) for you but they won't be cheap.
2. Use an inverter
I've built two ferrite-core based inverters one using a saturating core (eugh!) and one using a low power saturating core driving a bigger non-sat transformer (better) - these aren't as flashy as a MOSFET inverter but they are simple (sort of) and fairly foolproof.
Both produced +/- 35V from 12 V but you maybe only need +/-25V. Both have worked reliably for several years. Both need filter chokes in the audio leads, so though it is in principle simple there are four coils to wind!.
  Reply With Quote


20watt amplifierHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Questions about how to decrease the PASS A-40 amplifier into a class AB amplifier. novtango Pass Labs 4 14th February 2018 05:11 PM
modding small (10-20watt) tube amp for guitar? mondogenerator Instruments and Amps 4 21st December 2009 07:11 PM
Blown 20watt 4.7uf on soft start board ben62670 Solid State 4 26th June 2007 05:29 AM
Wanted: DIY amplifier builder with experience. I need a 0.7 ohm stable amplifier Audiophilenoob Swap Meet 34 16th May 2005 11:58 PM
Need good 10-20watt design grabo454 Tubes / Valves 13 8th April 2004 07:46 AM

New To Site? Need Help?

All times are GMT. The time now is 07:08 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio