daddyplaysbass Messages: 17 Registered: June 2004 Location: Arizona
Junior Member
I have a "72 150 amp wiht 2X12 cabinet. I get buzzing; the polarity switch has no effect. The buzzing stops when I touch my strings; starts up when I don't. I don't get buzzing with my other solid-state amps. Will a grounded cable help, or is there more I need to do?
Thanks
Just Give Me the Key, and Let Me Be!! Daddy Plays Bass!!!
stevem Messages: 4735 Registered: June 2004 Location: NY
Senior Member
If the switch as no effect you eitheir have a three prong cord already, or you ground switch is not funtioning.If you have a three prong cord get ground lift adapter and with a good pair of wire cutters trim back the big prong to match the smaller one. You will than be able to flip the plug around and get rid of the buzz.NOTE, YOU WILL NOT BE GROUNDED AND RUN A RISK OF SHOCK WITH OTHER ITEMS THAT ARE PLUGGED IN.
daddyplaysbass Messages: 17 Registered: June 2004 Location: Arizona
Junior Member
hi, back again. I have the original 2-prong plug. The ground switch appears to not be working as I reversd the plug in the outlet and some noise went away. Still buzzes when I'm not touching the strings though. I read earlier how to install a 3-prong cord; I printed it out, so I plan on doing that first.
Thanks
Just Give Me the Key, and Let Me Be!! Daddy Plays Bass!!!
daddyplaysbass Messages: 17 Registered: June 2004 Location: Arizona
Junior Member
Stevem, Thanks again; I'll try a noise-gate stomp box; will check out Guitar Center or Musicians's Friend. I can deal with somethingin-l;ine; timid about opening up the amp case.
Thanks again
Just Give Me the Key, and Let Me Be!! Daddy Plays Bass!!!
daddyplaysbass Messages: 17 Registered: June 2004 Location: Arizona
Junior Member
Hi
Got the amp out of the case. Found the on/off and ground switches were indeed broken. I carefully super-glued them and they seem o.k.
Now I am installing the 3-prong cord and have instructions from earlier posts but does anybody know of a source for a grommet thru the amp chassis? Radio Shack did not have them. I can do some "Southern Engineering" with electrical tape and silicon but would like a neater application. (I kept the 2-wire and grommet in case I ever sell the amp) *I use this amp as a players amp.
This site is awesome for all the help, maybe some day I can return the favor.
Thanks
Rich
Just Give Me the Key, and Let Me Be!! Daddy Plays Bass!!!
stevem Messages: 4735 Registered: June 2004 Location: NY
Senior Member
Unfortunaly a 3 wire power cord needs a larger grommet and in turn a larger hole in the amp case. You can get the grommet from antique electronics but you will have grind of file the hole bigger, unless their is a repair shop near you with the proper punches, you can have them make another new hole as their is no way to repunch a current hole. The other option is to knot the cord in, giving it some extra lenght in the head so it can not rip out from its soldered points. If need be I can mail you a grommet if you let me know the what gage 3 conductor wire you are using. 18 gage is good, 16 is better.
daddyplaysbass Messages: 17 Registered: June 2004 Location: Arizona
Junior Member
Hi Steve
Things are working out. I found a round grommet at True Value, Pushed the 3/18 gage 3-prong cord thru it and got it in the existing hole. The cord is tight; the grommet a tad loose but I'll seal it inside with a dab of silicon.
Thanks
Just Give Me the Key, and Let Me Be!! Daddy Plays Bass!!!
daddyplaysbass Messages: 17 Registered: June 2004 Location: Arizona
Junior Member
Well, I got the 3-prong cord installed and she's working very well. I am worried about the blue switches however; I repaired both using J.B. Weld. I would like to not have to push them anymore. Does it hurt if I leave the amp on and mearly plug/unplug from the wall? Plan "B" is to plug it into a surge protector and use the surge protector switch. Plan "C" is to have a rocker switch installed on back and use it for on/off and polarity.
My next job to use this amp is August 13th so I have time.
Thanks
Just Give Me the Key, and Let Me Be!! Daddy Plays Bass!!!
stevem Messages: 4735 Registered: June 2004 Location: NY
Senior Member
Both of my switches on my original 250 broke over 20 years ago, what I did was strap a small nylon cable tie on the left and right side of the switch as you view them from above and they have been fine since then. I also did this on my other 250s and 150 to prevent them from breaking. Their is no harm in leaving the amp on and unpluging it or just turn it on or off with a power strip.