Motorboating in Peavey Classic 30

[pulsar705]

hi,

I did some mods to my amp (master volume and footswitchable boost from Ahola's site) but yesterday when I increased the post or master volume started a motorboating (right name?).Suggestions?

thanks!

[bnwitt]

try moving the wires connected to the new master volume or other mod while it is motorboating to see if you can get it to stop. It is probably lead dress on the mods.

[pulsar705]

try moving the wires connected to the new master volume or other mod while it is motorboating to see if you can get it to stop. It is probably lead dress on the mods.

I had turned two hour ago(my home) and now it works fine.

[tubeswell]

The usual rule of problems in a modded factory amp that worked fine before-hand is it was because of something you did in the mod. Go back and re-check the mod. Did you use shielded cable for the MV control? (those PC boards are pretty close together and have absolutely everything on them, including filter caps about right above where the MV control wires insert into the bottom board).

[pulsar705]

The usual rule of problems in a modded factory amp that worked fine before-hand is it was because of something you did in the mod. Go back and re-check the mod. Did you use shielded cable for the MV control? (those PC boards are pretty close together and have absolutely everything on them, including filter caps about right above where the MV control wires insert into the bottom board).

yes,i did everything correctly.Certainly the lighting plant of the night club was faulty.

BTW Anyone has added a pot to adjust the boost volume? It's possible this?

[Enzo]

My first thought was that the output transformer plug was inserted backwards.