Very basic chip amp question - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

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 July 2003, 10:51 PM   #1
diyAudio Member
leadbelly's Avatar
Join Date: Dec 2002
Location: Calgary, Alberta
Default Very basic chip amp question

Let's say I wanna build an IGC sub amp...since I have control of amp construction and sub construction:

what is the difference, quality and/or level, if I build:

(1) a 2 chip parallel IGC, which I would then then drive the sub's 2 voice coils in parallel for a nominal 4R load.

(2) a 2 chip bridged IGC, which I would then drive the sub's 2 voice coild in series for a nominal 16R load.

The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts. Bertrand Russell
  Reply With Quote
Old 16th July 2003, 07:37 AM   #2
diyAudio Member
Join Date: Aug 2001
Location: Bath, UK
The easiest solution would be to build two identical gainclones driving one voice coil each. This would avoid the additional circuitry needed for parallel operation (servos, load-share resistors etc). Also, there's no power benefit to paralleling two GCs into 4R over two seperate GCs driving 8R each.

Come to think of it, there's also no benefit bridging two GCs into 16R - the power will be the same as two seperate GCs driving 8R each.

Nice one,
  Reply With Quote
Old 16th July 2003, 08:20 AM   #3
diyAudio Moderator
pinkmouse's Avatar
Join Date: Apr 2002
Location: Rotherham, England
Yup, I agree, two normal GCs, one per VC.

Or, you could just drive one coil with your bridged/paralled GC, and use the other with a 250Ohm wirewound pot wired across it, that way, you can tweak your Q for room response.
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
  Reply With Quote
Old 13th August 2003, 04:25 PM   #4
nowater is offline nowater  Australia
diyAudio Member
Join Date: Sep 2002
Location: south
Default DC offset on the input?

How much DC offset on the input will the LM3875/3886 chips accept? A few volts? Just wondering if a cathode follower valve driving the power op amp *must* be DC isolated.

I couldn't find it from the datasheet.
  Reply With Quote


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
a basic diy question for my chip amp then_dude Chip Amps 12 13th October 2007 11:05 AM
amp question basic rec rebith75 Solid State 3 16th March 2007 05:43 PM
Need suggestions for basic chip amp kit percy Chip Amps 5 18th August 2004 04:08 PM
really basic question cuallito Tubes / Valves 6 15th April 2004 08:25 PM
Basic question Tommy Solid State 6 22nd February 2004 03:08 PM

New To Site? Need Help?

All times are GMT. The time now is 10:46 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2