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

impedance mismatch?
impedance mismatch?
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 16th December 2004, 06:00 PM   #1
Milkduds is offline Milkduds  United States
diyAudio Member
 
Join Date: Oct 2004
Location: Southeast US
Default impedance mismatch?

I recently finished a GC using Brian's kit. I'm impressed initially with the sound but last night I replaced an AVA mosfet 100w/chan (old Dynaco ST150) with the gainclone and noticed not so good bass performance. The application is a bi-amplified speaker system using a S&B TX102 TVC driving an active xover. Signal below 200 hz is sent to the GC (or mosfet amp) for bass duties. Speakers are big Altec 515s. What I'm hearing...... the mosfet amp gives tighter more tuneful bass performance. The GC is a little uncontrolled and tubby sounding. Bass notes seem to all run together.

Any idea how to analyze this problem to see if it is an impedance issue?

Jim D.
  Reply With Quote
Old 16th December 2004, 06:13 PM   #2
Bill Fitzpatrick is offline Bill Fitzpatrick  United States
diyAudio Member
 
Bill Fitzpatrick's Avatar
 
Join Date: Jun 2001
Location: Eugene, OR
As I recall, GC builders use more supply capacitance when the amp is confined to bass duties. Try 10,000 mfd.
  Reply With Quote
Old 16th December 2004, 08:23 PM   #3
demogorgon is offline demogorgon  Norway
diyAudio Member
 
demogorgon's Avatar
 
Join Date: Jul 2004
Location: Behind you.
Send a message via MSN to demogorgon
lots of capacitans and a snubber should do the job. 2*1500uf on chip is nothing near enough for bass, and not enough for anything else either, or at least so i think, having compared 2*1000uf per board, 2*1000uf per board+2670uf per rail in the PS, 2*1000 per board+6200 in the PS, and finally, and what i ended up using, 2*1000uf per board+ 6200uf per rail en the PS with a snubber. read carlosfm's post about the big capacitans psu for chipamps. it's on the first page.

regards
marius
  Reply With Quote

Reply


impedance mismatch?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
impedance mismatch ddoyle Multi-Way 6 17th January 2008 04:06 PM
INA134 and input impedance mismatch redrabbit Solid State 20 30th September 2007 09:38 AM
Impedance Mismatch sushizen Full Range 1 16th November 2006 01:18 PM
impedance mismatch headaches. xstephanx Multi-Way 11 10th April 2006 07:36 PM


New To Site? Need Help?

All times are GMT. The time now is 05:36 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki