Can I use-35-0-35 volt DC for Leach 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 8th August 2005, 03:10 PM   #1
Wynand is offline Wynand  South Africa
diyAudio Member
 
Wynand's Avatar
 
Join Date: Mar 2005
Location: Cape Town
Default Can I use-35-0-35 volt DC for Leach Amp?

The subject line saiz it all...if not, what is the minimum voltage rails required? ANY info will be appreciated.
  Reply With Quote
Old 8th August 2005, 03:25 PM   #2
loek is offline loek  Netherlands
diyAudio Member
 
Join Date: Feb 2005
Location: The Hague
Default leach psu

My old Leach(1980) runs fine on 2x 40v DC...
Loek
  Reply With Quote
Old 8th August 2005, 06:26 PM   #3
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
your peak output voltage will be about 28V.
this limits your power to about 50W into 8r, about 90W into 4r and about 130W into 2r. I have assumed a 300VA transformer driving both channels at the same time.
All these speakers can be of the severe rating (60degree phase angle) since the low voltage rails do not stress the output transistors.
Since it performs so well into 2r you could consider bridging if you need more power;- 180W into 8r at 60degree phase angle. The 300VA and two PCBs now form a single channel amp. It would be cheaper to buy a higher voltage transformer for more power.
__________________
regards Andrew T.
  Reply With Quote
Old 8th August 2005, 06:57 PM   #4
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
Leach version 4.5 needs in excess of 40 volts to perform at its best - that is the reference voltage for the input stage cascode. Earlier versions did not use these zeners, and may perform well on lower rails. IIRC, Dr. Leach recommends >45V minimum.
  Reply With Quote
Old 9th August 2005, 07:56 AM   #5
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
Easy to change the zener, or run a high voltage tier for the front end.
  Reply With Quote
Old 9th August 2005, 10:31 AM   #6
skaara is offline skaara  Slovenia
diyAudio Member
 
Join Date: Jun 2002
Location: Europe, Slovenia
Just change the zeners and it should work fine, i did that once for +-36V supply voltage and it worked well.
  Reply With Quote
Old 9th August 2005, 01:55 PM   #7
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Quote:
Originally posted by AndrewT
you could consider bridging if you need more power
Now, what would be the slewrate of a bridged Leach amplifier ?
__________________
No More Mr Nice Guy
  Reply With Quote
Old 10th August 2005, 07:10 AM   #8
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
Slew rate is not important.

Since good audio performance is 2V/µS per peak volt of output, what we are specifing is rise time.

The rise time is substantially unchanged in bridge mode, as the slew rate doubles to go along with the doubling of the voltage swing.
  Reply With Quote
Old 10th August 2005, 10:41 AM   #9
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
And if voltage of the output rails is halved, then bridged ?
Same output, double slewrate, halve the risetime ?
__________________
No More Mr Nice Guy
  Reply With Quote
Old 11th August 2005, 07:24 AM   #10
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
The rise time shouldn't really change, and that's all that matters.
  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
My Leach Amp Clone (LEACH 150) panson_hk Solid State 32 22nd May 2014 11:25 AM
High Current Leach/leach super amp bowdown Solid State 41 2nd March 2011 02:15 PM
Switching 230 Volt Transformer to 120 Volt OMNIFEX Parts 10 6th April 2008 04:34 PM
Leach Superamp vs Leach 4.5 Samuel Jayaraj Solid State 4 26th October 2002 09:20 AM
Leach amp vs super Leach amp supernet Solid State 0 21st February 2002 10:16 PM


New To Site? Need Help?

All times are GMT. The time now is 02:19 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