Building Bassman

Discussion in 'Amps and Cabs [BG]' started by Techmonkey, Feb 18, 2005.

  1. Techmonkey


    Sep 4, 2004
    Wales, UK
    Right, well I have a Carlsbro Kickstart 25 bass amp... It's, well, not bad... Infact I like the sound, but the quality is aweful, if I put it past half volume the cabinet rattles itself to pieces, and the power transformer died twice... So I think it's about time I got a new amp :smug:
    Well I thought it's been a while since I've done a full blown electronics project. It's all good fixing peoples Squiers when solders break etc... But it gets a bit boring after a while. So I decided I should build an amp and kill two birds with one stone.
    My search took me to one amp; The Fender Bassman 5f6-a tweed amp.
    So moving on to the point - I've got the schematics, I can get all the parts online... Thing is, I live in the UK... So I thought, is there such a thing as a power transformer for the tweed bassman that would work in the UK? And if there is, can I just ground the amp straight to the mains instead of having a ground switch?
    Thanks for your time!
  2. Angela electronics has a wide selection of configurable Hammond power transformers. Do you know the output voltages and amps you need?
  3. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    The ground switch was used with the original 2 wire A/C connection. With a grounded 3rd lug on AC just ground the chassis to that, with .1 mfd. bypass caps and MOVs from both A/C legs to the chassis. Also, upgrade the main power supply (B+) caps to as high a MFD value as you can fit in the case you're using. A rackmount makes the most sense as far as that goes, preferably fan cooled.
  4. Techmonkey


    Sep 4, 2004
    Wales, UK
    Thanks for the help! I think it's an 8087 transformer... There seems to be 2 6.3v wires for the heaters and 2 325v wires going to the GZ34 valve... Then there's 2 wires going straight to ground.
    However there's 3 other wires I can't speak for, one going to the rectifier and 2 more going to the GZ34... Any ideas?