Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

Another Very different clone as promised.
Another Very different clone as promised.
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 15th March 2011, 01:53 PM   #1
tom wesley is offline tom wesley  United Kingdom
diyAudio Member
tom wesley's Avatar
Join Date: Jun 2010
Location: Pickering, North Yorkshire
Default Another Very different clone as promised.

Here is the second LM 3875 amp i mentioned at the end of my previous post.

This begn life as a disco light i was given by a pub landlord as it kept blowing all the pubs fuses??. (seized motor). Any how i always had the idea of puuting an amp in it and after a couple of years finally did. I bought a 2nd kit from Audio sector for my girlfriend Gemma who did most of the soldereing and made a great job. We then had to very carefully get it in the chassis. This caused a few rows but we got there, only the one heatsink is actually in use with the left channel. The right is mounted further bck on the mounting bracket boss which works fine. the fan runs on a seperate small 12v traffo in PSU box and she wants to mount white LEDS in it now???

I have also shown the PSU which is one of a identical pair i made using a 160va with twin 25v secondariers in a CT type setup with a 35a can type rectifier in the amp chassis. The Psu chassis is saftey grounded which is then taken to the amps pwr star which is the mid point on the neg speaker outs.
Dual inline 3a fuses mounted at rear of PSU and also a IEC outlet lead to power its twin if i build monoblocks.
The light runs off 240v mains and is from a kitchen extractor fan with the added bonus of not being the other side of the traffos.

This amps DC rails are running 38 - 40v do to the PSU giving 27 - 28v ac because of wall V. At this voltage the amp to me sounds more powerfull not in the obvious sense i cant really explain what i mean. My girlfriend uses it at hers along with rack mount active x-over and vintage sonics cabs (8ohm, 20w, 93db @1w/1m). Sounds great and with these extremley sensitive old cabs is V.Loud without any audible distortion. We dont want to damage cabs so re carefull and the fans a must in this chassis!

We wanted the amp to resemble a V-Twin engine and The PC heatsinks work to do this, she is going to spray them i think. All in all a very challenging build but well worth it. This amp is so compact it cn be just picked up and is v. portable so is good for doing small parties etc.


Gems Internal.JPG



gems V-Amp front.JPG

gems amp back.JPG
Attached Images
File Type: jpg gems v-amp inside.JPG (823.0 KB, 196 views)
File Type: jpg 160 VA 25v Toroid.JPG (153.1 KB, 166 views)
  Reply With Quote
Old 18th March 2011, 10:41 PM   #2
ianpengelly is offline ianpengelly  United Kingdom
diyAudio Member
ianpengelly's Avatar
Join Date: Oct 2006
Excellent reuse of an old disco light (I am presuming?)!
  Reply With Quote


Another Very different clone as promised.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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dunlap Clarke schematic as promised. jez Solid State 8 7th September 2011 09:15 PM
First DIY amp pics-as promised! mr mojo Tubes / Valves 42 13th January 2007 04:16 PM
As promised.......the Phase Noise Files..... Jocko Homo Digital Source 27 5th April 2003 10:39 PM
Question regarding ProAc 2.5 Clone and Tempo 2 Clone zoooh Multi-Way 5 11th March 2003 08:19 PM

New To Site? Need Help?

All times are GMT. The time now is 10:59 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio