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.

antique fender bassman 50 retubed HELP
antique fender bassman 50 retubed HELP
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 10th June 2006, 10:55 PM   #1
firefart_1st is offline firefart_1st  Portugal
diyAudio Member
 
Join Date: Jun 2006
Send a message via MSN to firefart_1st
Exclamation antique fender bassman 50 retubed HELP

a friend of mine had put a fender bassman to repair on local guy. but he didnt check the amp properly. he retubed it and changed all the power supply caps fixed the bias section and bla bla bla but now it has LOTS of gain. it distorts BADLY i0m tring to get the gain better but that new ( sovtek ) tubes are hungry for gain.

i have about 140 / 150V feeding the preamp tubes and the cathode resistor is now 2K2 ohm. it has less gains but stil has to much.

sould i uze a kind of voltage divider on each gain stage of this amp ? or what kan a go better ? are the preamp tubes 'cold' with 150V ? anr with 2k2ohm on the cathode ?

The schematics are at

http://www.schematicheaven.com/fende..._bassman50.pdf

on the last gains stage before the phase spliter i get the cleanest sound that i ever heard.

so the gain problem is before that.

please help

i home i'm clear enough.

tankx in advance ^^
__________________
music music music music
  Reply With Quote
Old 26th May 2008, 11:06 PM   #2
davealias33 is offline davealias33  United Kingdom
diyAudio Member
 
Join Date: May 2008
Red face bassman 50 head, 1973

obviously missing a resistor to ground or a wrong value's been fitted, could be a faulty capacitor or bad valve. you can't really go wrong these are such simple circuits.. you can e mail a close up of the amp i'll have a look, or send it to me with the valves and case removed and i'll fix it. (you pay carriage both ways though..)
  Reply With Quote

Reply


antique fender bassman 50 retubed HELPHide 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
Prototype fender bassman for trade - echosonic or standel 25l15 TelecasterTech Instruments and Amps 1 24th January 2012 05:53 PM
Fender Bassman Ten Benny Bennett Instruments and Amps 2 2nd April 2009 01:01 PM
Fender Bassman- AB165 capacitor toss up Willampsburn Instruments and Amps 1 9th February 2008 02:12 AM
Fender Bassman PT Rewind OKBill Instruments and Amps 4 14th January 2007 02:51 PM
Modifing A Fender Bassman Scheme amirmk Instruments and Amps 5 16th September 2005 07:34 PM


New To Site? Need Help?

All times are GMT. The time now is 12:39 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki