Help - replacing plastic 4-prong jack

[lowell]

Hello,
Could anyone please advise on replacing a 4-prong stock jack in a Hiwatt L100R with a radio shack shorting jack? I've done it but it seemed to have changed the sound of the amp and the clean channel is no longer totally clean... it has some dirt to it....???

Thanks!

[Amp Kat]

You may have a open gound maybe ? Trace the traces on the board and see where they go . 3 of the pins on the 4 pronged jack or usually shorted to ground. The tip is sometimes shorted too until you put a 1/4" phono plug in and then that is the signal to the grid leak resistor or coupling cap. With the shorting jack theres only two pins so (of course depending on stereo or mono jack) one is tip and one is sleeve. If your only wiring one from the board and one from ground your omitting two connections that may be needed to tie to the jack. You may have to wire 3 to the sleeve and the tip to the signal trace. The jack shorts to ground or sleeve until you put a plug in it and then only that pin goes to signal. If the jack is stereo (3 pins) you may have to tie ring and sleeve together.