diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Solid State (http://www.diyaudio.com/forums/solid-state/)
-   -   will this work (http://www.diyaudio.com/forums/solid-state/137500-will-work.html)

rtill 28th January 2009 09:03 PM

will this work
 
2 Attachment(s)
just curious if this would work

Tube_Dude 28th January 2009 09:33 PM

Re: will this work
 
Quote:

Originally posted by rtill
just curious if this would work
Yes! :cool:

pacificblue 28th January 2009 10:00 PM

Second schematic. See also the updated version P3A.

AndrewT 28th January 2009 10:03 PM

The Vbe multiplier is ineffective due to the limiting effect of the two series diodes.
That 1.2V to 1.3 volts will probably bias the amp into ClassB

Do not put the wiper of the vbe multipler to the base of the transistor. If the wiper goes open circuit it can lead to a blown output stage and that in turn could blow your speaker.

One pair of robust output devices can give 100W into 8r0 using ~+_50Vdc.
But to get 100W from the +-42Vdc requires one to use 4r0. This is asking too much from one pair of small output devices.

rtill 28th January 2009 10:51 PM

I was planning on using 4 ohm speakers.

darian 28th January 2009 11:01 PM

Just buy an AKSA amp. That is what your schematic is (except the 2 useless diodes). This type of topology has been working for years and will be working forever.

Where have you been? :) LOL

thunderpld 29th January 2009 02:24 PM

Could use a current source.

lineup 29th January 2009 05:42 PM

Quote:

Originally posted by AndrewT

One pair of robust output devices can give 100W into 8r0 using ~+_50Vdc.
But to get 100W from the +-42Vdc requires one to use 4r0. This is asking too much from one pair of small output devices.

42 Volt rails.
50 Watt into 8 Ohm, yes.
For 100 Watt at least 45 and probably like AndrewT suggest 50 Volt
(40x40) / (2x8) = 100 Watt into 8 Ohm
where 40 is the peak voltage from supply.

Your drawn amplifier will work even if it is very basic.
There is nothing wrong with your circuit in schematic. :)

AndrewT 29th January 2009 05:51 PM

but extracting 100W into 4ohms is more onerous than 100W into 8ohms.
One pair will struggle to deliver into a 4ohm load.

ostripper 30th January 2009 02:00 AM

Quote:

Just buy an AKSA amp
AKSA is $$$$.. I think trill wants something economical.
DX amp with 2 pair OP devices or my Frugalamp 1 would
do 4 ohms nice..
Or Quasi NMOS.. all these amps have support, PCB work
and cost 25-50$ (not including power supply) as well
as using very common devices..

OS


All times are GMT. The time now is 11:54 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