Initial Project: 300W Power Amp - 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 6th January 2010, 01:02 AM   #1
bharfhy is offline bharfhy  Brazil
diyAudio Member
 
Join Date: Apr 2005
Location: Sao Paulo
Send a message via ICQ to bharfhy
Default Initial Project: 300W Power Amp

I found this on Google. power amp 300W
I am very interested in riding. I already started the scheme in KiCad
As I am inexperienced in sound I'd like information from an expert on the quality of the project.
It is worthwhile to mount it or recommend me a better design?
  Reply With Quote
Old 6th January 2010, 02:12 AM   #2
diyAudio Moderator Emeritus
 
Iain McNeill's Avatar
 
Join Date: Oct 2007
Location: Santa Cruz, California
This is definitely not a first time project. Learning on something that has such power capability is a recipe for electrocution or house fire.

I would recommend something much more simple. Check out Nelson Pass' designs in his forum here or at his website. Also, look at the "chip amp" designs which can sound just as good (not as loud) but are more forgiving for beginners.
  Reply With Quote
Old 6th January 2010, 09:54 AM   #3
diyAudio Member
 
Aldotin's Avatar
 
Join Date: Dec 2009
That's the ETI-466 amplifier (designed by Barry Wilkinson).
This link may help:
ETI-466 Amplifier Technical Review
  Reply With Quote
Old 6th January 2010, 11:47 AM   #4
GK is offline GK  Australia
Account disabled at member's request
 
Join Date: Jan 2006
I've still got all the original magazines featuring these projects. That ETI design wasn't noted for its reliability. The CFP-like output stage with voltage gain was prone to oscillation and smoke. Cloning the design today with modern versions/makes of the same power output devices may even be risky due to the fact that the fT's are likely to be higher than they were back then.

The 300W Playmaster of the same vintage was a much better and stable design:

Electronics Australia Playmaster 300, 300W Amplifier Module

Last edited by GK; 6th January 2010 at 11:50 AM.
  Reply With Quote
Old 6th January 2010, 12:19 PM   #5
diyAudio Member
 
Aldotin's Avatar
 
Join Date: Dec 2009
Looks like a nice solid design from the 70's era!
For public address purposes it's OK, but as Hi-Fi/audiophile amplifier it's outdated now...

Anyway the Q14-Q16 driver pair seems to be underrated. I'd choose a stronger driver pair - for example the MJE15030/31 pair from Onsemi would do the job!

Quote:
Originally Posted by GK View Post
I've still got all the original magazines featuring these projects. That ETI design wasn't noted for its reliability. The CFP-like output stage with voltage gain was prone to oscillation and smoke. Cloning the design today with modern versions/makes of the same power output devices may even be risky due to the fact that the fT's are likely to be higher than they were back then.

The 300W Playmaster of the same vintage was a much better and stable design:

Electronics Australia Playmaster 300, 300W Amplifier Module
  Reply With Quote
Old 6th January 2010, 01:46 PM   #6
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
Quote:
Originally Posted by Aldotin View Post
Looks like a nice solid design from the 70's era!
For public address purposes it's OK, but as Hi-Fi/audiophile amplifier it's outdated now...

Anyway the Q14-Q16 driver pair seems to be underrated. I'd choose a stronger driver pair - for example the MJE15030/31 pair from Onsemi would do the job!
the only thing thing that is outated are the bjts
wich are quiete old and can be bested by more recents parts..
for the rest, the dual differential proposed in this thread has no
advantages, moreover, the compound output stage is less safe than the
classic one on the australian amp..
  Reply With Quote
Old 6th January 2010, 02:28 PM   #7
diyAudio Member
 
Aldotin's Avatar
 
Join Date: Dec 2009
I referred to the "Playmaster", not the "ETI-466".
Playmaster's OP stage is EF and differential stage isn't dual.

Quote:
Originally Posted by wahab View Post
the only thing thing that is outated are the bjts
wich are quiete old and can be bested by more recents parts..
for the rest, the dual differential proposed in this thread has no
advantages, moreover, the compound output stage is less safe than the
classic one on the australian amp..
  Reply With Quote
Old 6th January 2010, 02:55 PM   #8
diyAudio Member
 
andrewlebon's Avatar
 
Join Date: Feb 2008
Default playmaster 300 watts

Great amplifier for pa using 4 pairs 2n3773 still going strong built 12 years ago
will post pictures tomorrow can it be modified for higher output using newer
semis
thanking you
andrew lebon
  Reply With Quote
Old 6th January 2010, 03:09 PM   #9
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
that is a difficult first project.
Start with something much simpler and much lower voltage.

BTW, the 200W into 8r0 is probably right. If the 310W into 4r0 is also correct then it indicates that this is a bad design for a 4ohm speaker.
Don't use it on 4ohm or 4 to 8ohm speakers.
It might work with 6ohm speakers, but you should take the others advice and select a better DIY 200W design as your second or third project.
__________________
regards Andrew T.
  Reply With Quote
Old 6th January 2010, 03:26 PM   #10
diyAudio Member
 
Aldotin's Avatar
 
Join Date: Dec 2009
Quote:
Originally Posted by AndrewT View Post
BTW, the 200W into 8r0 is probably right. If the 310W into 4r0 is also correct then it indicates that this is a bad design for a 4ohm speaker.
Are you sure?
A 300W/4Ohm rated conventional PA amplifier usually gives ~200W on 8Ohm load.
  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
Ohmite 32 ohm 300W rheostat power resistor boywonder Swap Meet 0 31st May 2009 02:37 AM
need power supply advice for future power amp project. boricuaso Chip Amps 13 6th February 2008 03:24 PM
4 sale or Trade:TAS5261DKD 300w Digital Power amp IC"s!!! Minion Swap Meet 4 18th January 2007 06:05 PM
300W Power Amp bostjancek Solid State 10 7th December 2005 08:35 AM
sam's 300W or eti-466 : power supply bigpanda Solid State 3 1st April 2005 09:17 PM


New To Site? Need Help?

All times are GMT. The time now is 04:29 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