I have a Ampeg SVT 6 Pro I bought new in 05 and it keeps feedbacking. It started about a month ago but was real bad last night. I keep the amp at my groups jam spot and only use it once or twice a week. I thought something was wrong a while ago but ignored it I guess. Anyway, it gomes ands goes and neither volume or gain seem to affect it. It,s only when I turn the volume on the bass off that it subsides. The guitarist I jam w/ thinks a preamp tube is bad. I sure gould use some help from anyone that knows about hybred amps or amps in general. Thanks.
