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.

P68 300w sub amp problem
P68 300w sub amp problem
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 8th October 2003, 09:50 PM   #1
flashback is offline flashback  Macedonia
diyAudio Member
 
Join Date: Oct 2003
Location: Macedonia
Question P68 300w sub amp problem

Hi everybody!!!
I`m new to this forum and i`m well surprised how people try to help one to each other!
I have built Rod`s 300w sub amp but i have a small problem-quiescent current! As described it should be arround 55mv(55ma)on R16,or R17.My result n R16-50ma;on R17-100ma,and i have a lot of heat on R17!!! No other problems.Can anybody help!!!
I have built a sealed sub encosure using Infinity Kappa 120.3se and this amp is part of that enclosure so it really matters to me to correct this problem before bursting some output device (2SA1943 and 2SC5200)
Thanks!!!
  Reply With Quote
Old 9th October 2003, 06:06 AM   #2
DieterD is offline DieterD
diyAudio Member
 
Join Date: Dec 2001
Location: Howick South Africa
Hi,
I have built four of these amps and they have all worked first time.

Carefully check every component and make sure its correct, especially resistor values, often we grab a 22 ohm instead of a 220 ohm.

DieterD
  Reply With Quote
Old 9th October 2003, 07:12 AM   #3
Vigier is offline Vigier  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Hi,

indeed: check the values of all components around the transistors.

2nd idea: did you match the transistors? There could be a really big difference between them in their properties (hmm...bad english ) .
In 9 of my amps I use Toshiba's GT20D101 and GT20D201. When parallelling those I measured a quiscent current of 184mA and 346mA for the other transistor. I had to match them, and now the problems have been solved (339mA/346mA).

Grtz, Joris
  Reply With Quote
Old 10th October 2003, 09:58 AM   #4
Tazzy is offline Tazzy
diyAudio Member
 
Join Date: Jul 2002
Location: Netherlands
Send a message via MSN to Tazzy
Flashback, any luck in fixing your amp?
  Reply With Quote
Old 12th October 2003, 08:37 AM   #5
flashback is offline flashback  Macedonia
diyAudio Member
 
Join Date: Oct 2003
Location: Macedonia
Talking No result

Hi guys!!!
No success at all.I`ve removed the kse350 transistors which were mounted as a replace for the mje350 at the beginning. Now with the mje`s the result is even worse!!!
At the point where i had a normal quiescent current, now i have only 10-20ma(measured with analog multimetter).I just can understand what is happening??!!??!!
  Reply With Quote

Reply


P68 300w sub amp problemHide 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
300W P.A. amp drummer_Dave Solid State 4 19th February 2009 10:45 PM
300w rms amp leander Parts 1 8th September 2005 09:43 AM
300w sub amp help zoki_g Solid State 3 1st May 2003 10:49 AM


New To Site? Need Help?

All times are GMT. The time now is 06:01 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