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

Rockford P8002
Rockford P8002
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 7th December 2018, 02:32 AM   #1
seankane is offline seankane  United States
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Default Rockford P8002

Hello all. Working on a P8002 board number PC-4708-B.


I replaced all the outputs, gate resistors and source resistors in this amp. The amp powers and idles fine, and will bias. It also produces clean audio on both channels. I did also replace some smd diodes and transistors and various resistors.


My question is about the bias. It draws current sooner in the pot rotation than I'm used to seeing and mv readings across the source resistors vary from .2mv to 1.6mv


Should they all have the same readings or is this normal?
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote
Old 7th December 2018, 03:05 AM   #2
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
The threshold voltage may be lower than the original FETs.

The threshold voltage of the FETs or the source resistor actual value can make a difference between the parallel resistor readings. A better test is to drive the amp to about 10v AC into a dummy load and then measure the voltage across the source resistors. They should read very nearly the same with that test (within a few percent of each other).
  Reply With Quote
Old 7th December 2018, 03:19 AM   #3
seankane is offline seankane  United States
diyAudio Member
 
seankane's Avatar
 
Join Date: May 2010
Location: Washington State
Ok I rotated one pot just slightly ccw and now they all read the same. I usually do it by watching current draw on my meter like shown on the tutorial. I have noticed that sometimes when you back it off to stop the draw you have to go a little more sometimes.
__________________
Pyramid 52 Amp Power Supply----Fluke 787 Processmeter----Tektronix 465 Scope----Velleman HPS40 Scope----Soldering Iron----Desoldering Iron----Hejet HJ 500-S Heatgun----DM4070 Digital LCR Meter----Propane Torch
  Reply With Quote

Reply


Rockford P8002Hide 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
Rockford Fosgate p8002 help. rhempz01 Car Audio 18 28th February 2018 02:30 AM
Rockford fosgate P8002 goes into protect chipper Car Audio 5 23rd October 2016 05:34 PM
Rockford fosgate punch p8002 channel repair chipper Car Audio 2 15th July 2016 10:19 PM
rOCKFORD P8002 edfirebird68 Car Audio 18 6th January 2016 04:39 AM
NOISE on audio system (Rockford 500a2, Sony xec1000, rockford PA2) stoke Car Audio 6 1st October 2010 11:21 PM


New To Site? Need Help?

All times are GMT. The time now is 10:58 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki