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

Instruments and Amps Everything that makes music, Especially including instrument amps.

SWR Workingman's Bass
SWR Workingman's Bass
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 19th January 2013, 04:00 PM   #1
megastacco is offline megastacco
diyAudio Member
Join Date: Jan 2013
Question SWR Workingman's Bass

This was a thrift store find and the input jacks were in bad shape. Played well for all of the battle scars until .."pop" and a series of flutters went throught the speaker. Now,I get a hum and but no signal from the inputs. I am a novice but am not squeemish when it comes to this stuff..Any ideas????spare parts resources? personal experience? Thanks
  Reply With Quote
Old 19th January 2013, 05:47 PM   #2
Enzo is offline Enzo  United States
diyAudio Member
Join Date: Sep 2004
Location: Lansing, Michigan
What model is the amp, SWR made a number of Workingman amps, just like General Motors made several Chevrolet model?

Now, more specifics. When you say hum, is it a LOUD hum, or just annoying hum, or mere bacjground hum? If LOUD hum, look at the speaker cone. Does it move one direction and stay there? Or does it remain more or less at rest position. If it moves and stays, TURN IT OFF and do not connect a speaqker until we know it no longer makes DC voltage. DC voltage is what makes the speaker stick in one position, and it will destroy th speaker if left there.

If the speaker/DC-voltage thing is not the issue, then you may have lost a main filter cap. Cap could have failed or the solder to it may have cracked. It is also possible the low voltage supplies lost a filter cap, or for that matter even one went away completely.

So we ought to check all the power supplies. The power amp will have some voltage or other, both polarities, and it matters which model, it could be anywhere from 25v to 80v. The preamp runs on +15 and -15, so find those and see that they are up to voltage. All four of those need to be free of ripple.

Once we know what amp it is we can also try some thing to narrow it down, like using the FX loop jacks.
  Reply With Quote


SWR Workingman's BassHide 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
Need Help with a 1996 SWR Workingman's 12 Combo Amp KP11520 Instruments and Amps 18 17th August 2012 11:06 PM
Bass amp issues, swr redhead chicago_mike Solid State 18 8th August 2009 04:54 PM
looking for a swr mo´bass amplifier schematics jose8a Solid State 0 20th September 2008 11:37 PM
Spare parts source for SWR bass amps lundborg Instruments and Amps 5 19th July 2008 11:38 AM
DIY : SWR Interstellar OverDrive (bass preamp) miguel567_98 Tubes / Valves 13 15th February 2007 07:55 AM

New To Site? Need Help?

All times are GMT. The time now is 09:58 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio