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.

BA283 AM Biasing Trimpot Issue?
BA283 AM Biasing Trimpot Issue?
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 29th February 2016, 02:34 PM   #1
lesabb is offline lesabb
diyAudio Member
 
Join Date: Dec 2014
Default BA283 AM Biasing Trimpot Issue?

I am newbie and trying to build the pre-amp section of the Neve 1073. I decided to bread board the BA283AM ONLY as per the attached schematics. I think there is a problem but i canít seem to find it. The collector voltage on the 2N6248 is 20.6V. Shouldn't it be higher? When I turn the trimpot nothing happens. The Base voltage is ~10.6V and the E is at ~ 10V, which I think is OK but a bit higher than previously reported (~3V). Consequently, the C voltage of Q1 is at ~10.6V (much higher than the reported 3.6V). The transformer is connected to the 24V PSU and to the output of the BA283AM as per the schematics.Any troubleshooting ideas? Thanks

Luc
Attached Images
File Type: jpg 283AM Test copy.jpg (266.2 KB, 21 views)
  Reply With Quote
Old 29th February 2016, 03:34 PM   #2
Cortez is offline Cortez  Hungary
diyAudio Member
 
Cortez's Avatar
 
Join Date: Dec 2002
Location: Hungary
Try to simulate this cct. Then you will know how it works and then you can compare the reality to the values in the sim.
  Reply With Quote

Reply


BA283 AM Biasing Trimpot Issue?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
Kicker kx350.2 biasing issue EBBCO Car Audio 9 21st October 2012 08:42 PM
How to create a DC offset trimpot? reiver Solid State 13 15th June 2008 01:38 PM
low-biasing or high biasing in Class-AB amps kASD Solid State 124 18th October 2005 04:45 AM
Strange biasing issue when adjusting VBE EWorkshop1708 Solid State 30 6th July 2005 05:17 AM


New To Site? Need Help?

All times are GMT. The time now is 03:59 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki