redesign amp need - 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 15th June 2006, 11:18 PM   #1
prorms is offline prorms  United States
diyAudio Member
 
Join Date: Nov 2006
Send a message via ICQ to prorms
Default redesign amp need

Could anyone get this amp to put out 250ws?
Attached Images
File Type: gif reverspoweramp.gif (79.1 KB, 345 views)
  Reply With Quote
Old 16th June 2006, 06:31 PM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
having difficulty with my neck and my eyes. Must be my age!
can you confirm the output devices? 2pair MJ15003/4, drivers 1pair MJE?
__________________
regards Andrew T.
  Reply With Quote
Old 16th June 2006, 07:11 PM   #3
prorms is offline prorms  United States
diyAudio Member
 
Join Date: Nov 2006
Send a message via ICQ to prorms
Default yes

they are mj15003
mj15004
mje15034
mje15035
bd139
  Reply With Quote
Old 16th June 2006, 07:24 PM   #4
MikeB is offline MikeB  Germany
diyAudio Member
 
MikeB's Avatar
 
Join Date: Apr 2004
Location: GŁtersloh
Okay, after having put my monitor on the side and rearranged my neck i wonder where you get your ground from ?
You should have a split supply (like 2x36v in series with ground in the middle) or have a virtual ground.
As you can see you have -10v for v- and +60v for v+. This will float as it is in its mood and you have no defined inputvoltage.
I am still convinced that your outputstage protection does not work.

Mike
  Reply With Quote
Old 16th June 2006, 07:34 PM   #5
edl is offline edl  Hungary
diyAudio Member
 
edl's Avatar
 
Join Date: Oct 2004
Sorry, but that's one of the worst amp design I've ever seen...
  Reply With Quote
Old 16th June 2006, 08:28 PM   #6
prorms is offline prorms  United States
diyAudio Member
 
Join Date: Nov 2006
Send a message via ICQ to prorms
some one think could get this to work?????????????
  Reply With Quote
Old 16th June 2006, 08:35 PM   #7
MikeB is offline MikeB  Germany
diyAudio Member
 
MikeB's Avatar
 
Join Date: Apr 2004
Location: GŁtersloh
But that would be a new design and not a redesign. Anyway, the max watts into 8 ohms would be 60watts, not 250watts.
I suggest that you start with an existing proven design, just to get experience and less frustration.

You will definitely need a symetrical powersupply, giving a +/- voltage.

Mike
  Reply With Quote
Old 17th June 2006, 05:28 AM   #8
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default Try those values, it may work fine

You will need to change some resistors into trimpot...the 100 ohms units, and also the input 1K or 1K5.....using fix plus series devices, to equalize exactly the current to both halves and to reduce the of set to minimum.

It is around 32 milivolts, and of course, can be reduced.

This amplifier was only simulated, it was not assembled.

Thank you to call me to help.

But may work fine.

regards,

Carlos
Attached Images
File Type: jpg it may work fine.jpg (96.1 KB, 164 views)
__________________
Convertion of 8 speaker output wire into standard 2 wires; https://www.youtube.com/watch?v=toZjKw3uUMo; Unbeatable!; https://www.youtube.com/watch?v=u4tGBiqMnzQ
  Reply With Quote
Old 17th June 2006, 07:51 AM   #9
diyAudio Member
 
Greg Erskine's Avatar
 
Join Date: Jan 2002
Location: Sydney/Australia
Default OT, sorry

That face looks vaguely familiar.

Nice to see you back, Carlos.
__________________
Greg Erskine
  Reply With Quote
Old 17th June 2006, 09:35 AM   #10
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
considering ONLY the output stage and ignoring the earlier comments on the design applicability.

You will need about 4pairs of MJ15003/4 for 250W into 8ohms with a phase angle of 60degrees and Tc max<45degreesC running on about 72Vrails drooping to about 69V fully loaded. This same output stage will also drive 4ohms to 35degrees phase. But most speakers have much larger reactance than this.
The suggested stage is for 8ohms speakers or above.
I do not know if the drivers could cope with 4pair but if you proceed I can do the calculations for you.

You will need BIG sinks to keep this much power that cool if you set up a large Iq (4pairs @ 50mA/pair) or squeeze lots of output power from the amp. If you can keep them cool the transistors are capable of driving your output all day at any audio frequency.
__________________
regards Andrew T.
  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
Redesign of JBL L-100 pair malovich Multi-Way 12 26th June 2013 09:23 AM
Headphone Amp Redesign? orangeshasta Headphone Systems 9 10th July 2007 06:12 PM
What to do , repair , replace or redesign. fortuosity Multi-Way 0 10th May 2006 02:23 AM
Redesign a factory speaker sazaks Multi-Way 11 14th November 2001 08:31 AM


New To Site? Need Help?

All times are GMT. The time now is 01:14 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