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.

Leach Amp PS
Leach Amp PS
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 6th July 2001, 03:53 AM   #1
peter5 is offline peter5
diyAudio Member
Join Date: Jun 2001
I just completed a two channel Leach Amplifier but I can't get the power supply to work. There are three output leads on my transformer; two rated at 44 volts and one rated at 0 volts. They can either be connected in series for 44 volts at 9 amps or in parallel for 88 volts at 4.5 amps. I attempted to wire the leads in parallel by connecting the 0 volt lead to central ground and the other two leads to the ac connectors on the bridge rectifier. I don't think any current is drawn when the amp is on, but I have verified that the power plug, socket and switch all work.

Thank you.
  Reply With Quote
Old 6th July 2001, 04:14 AM   #2
GRollins is offline GRollins  United States
diyAudio Member
Join Date: Feb 2001
Location: Columbia, SC
The Leach, I believe, uses a standard power supply arrangement where the center tap of the transformer (0V) is connected to ground. The other two leads will go to the rectifier, yielding + and - DC which should go to separate banks of caps.
Always observe proper polarity on electrolytic caps.
The negative terminal of the cap on the positive rail will go to ground. The positive terminal will receive positive charge from the rectifier.
The positive terminal of the cap on the negative rail will go to ground. The negative terminal will receive negative charge from the rectifier.

  Reply With Quote
Old 6th July 2001, 04:16 AM   #3
grataku is offline grataku  United States
diyAudio Member
Join Date: Dec 2000
Location: -
are you doing exactly what it says here?


From your email I think you may be confused about series and parallel.

  Reply With Quote
Old 6th July 2001, 03:07 PM   #4
peter5 is offline peter5
diyAudio Member
Join Date: Jun 2001
Yes, my caps are attached correctly, but perhaps they could be broken. I have no way to test them. Also, could it be that they are too large? Right now I have 42,000 micro farads/rail. I checked the wiring diagram and everything is attached correctly. I did have my series/parallel explanation wrong. Sorry, it was a late night. I want the transformer leads in series. By your explanations, it seems that I have the transformer wired correctly, but what else could it be? Thank you for your help.

  Reply With Quote
Old 6th July 2001, 03:24 PM   #5
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
vdi_nenna's Avatar
Join Date: Oct 2000
Location: PA, USA
Leach Amp PS Send a message via Yahoo to vdi_nenna
Default Testing Caps

You can get a go/no-go reading from an analog multimeter.

Take the caps out of the circuit. Set you meter to a high ohms read, like kohms. Then attach the positive lead to the positive side of the cap, then the same for the negative.

If the cap is ok, the meter w/ jump to less resistance and work its way higher resistance. If it is a small cap, this will happen quickly. It is more obvious w/ large power supply caps.

If it is broken, you'll get infinite resistance.

Best practice would be to discharge the cap w/ a 5 to 10 watt 1k ohm resistor, just to be safe.

If you are using a bridge rectifier, make sure you have the AC end of the transformer going into the correct leads of the bridge. Some bridges are marked w/ ~ ~ for the AC input and then, + - for the DC output to the circuit.

Good luck,

  Reply With Quote
Old 6th July 2001, 06:45 PM   #6
peter5 is offline peter5
diyAudio Member
Join Date: Jun 2001
Ok, I found my problem and I feel like an idiot but I'll post my solution for those who are having a similar problem or are just in need of a good laugh. When I attached the transformer leads to the power cord I forgot to sand off the second layer of insulation. Anyway, thanks for all of the prompt help.

  Reply With Quote


Leach Amp PSHide 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
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
anyone have leach PCB? ilyash Group Buys 2 7th September 2007 10:36 AM
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 05:52 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio