Flames! help with Fender mod

Guest · Post by **Guest** » Sat Apr 09, 2005 7:43 pm

I got the tweed bassman preamp installed in the vibrato channel on my bandmaster but I'm not getting any sound? Any suggestions on where to look? How should the filtering be hooked up to it is my big question.

Flames1950 · Post by **Flames1950** » Sat Apr 09, 2005 11:58 pm

Neither channel has any sound or just the tweed?

Guest · Post by **Guest** » Sun Apr 10, 2005 2:29 am

I ended up getting sound out of the tweed channel, I forgot to hook the wire up to the phase invertor, duh. However it still did not work right. I was getting sound but the volume was weak. Any time I would turn to the bass up it would make this clicky noise until I turned it down again. I ended up getting really frustrated and put the circuit back to stock for now since I need to play tommorow. Once I put it back to stock the normal channel stopped working. I don't know what the deal is but I don't know enough to trouble shoot it well and I don't have a multimeter at the moment. Do know you anywhere I get could some info on doing a mod like this?

Billy Batz · Post by **Billy Batz** » Sun Apr 10, 2005 2:49 am

Im guessing that clicking sound is almist 100% motorboating. A low frequency oscillation that is common to show itself as a clicking or machine gun type sound that changes speed/intensity with knob positions and spontanously starts up when you reach a certain volume level or level on a control like bass. Its annoying.

If you lay it out right and dress your leads neatly its easy to avoid POs in a Fender. Maybe some pics would help. Go over every connection. Are you sure you didnt miss anything?

Flames1950 · Post by **Flames1950** » Sun Apr 10, 2005 9:19 am

AS far as the normal not working now, are you sure all those over-the-board wires Fender uses for getting the preamp signal to the mixer and phase inverter are correct? What about the over-the-board wires that move your B+ to each stage?

Guest · Post by **Guest** » Sun Apr 10, 2005 10:33 am

I got it back to stock so i could play it today. I'll scan the layout drawing i was using later today so you guys can check it out. Thanks for all the help.

daniel · Post by **daniel** » Sun Apr 10, 2005 10:45 am

this keeps calling me a guest dangit

daniel · Post by **daniel** » Tue Apr 12, 2005 7:25 pm

Haven't had a chance to upload that layout yet. It was a little weird since I was using the existing holes on the board. One thing I'm not sure I had right is the filtering. How exactly should the tweed channel be hooked up to the filter caps? Also, motorboating is definitely what is going on, what are some common causes of this? Sorry for all the questions, I really appreciate your help. If anyone knows where more info is available on installing a cathode follower tone stack in a silverface amp let me know.

Billy Batz · Post by **Billy Batz** » Tue Apr 12, 2005 7:50 pm

Theres a few but a common one is coupler values.