DIY tube overdrive pedal

[M29]

Yes indeed this is very interesting Jim, I have an ART preamp setting around here too!

[Duffy]

I have one of the studio art mic preamps and can't figure out how to use it. I have been using it in a small room and it "squeals" like H!#! when I turn up the knobs over anything but about normal volume.

I am positive I am doing something wrong and don't know how to use the item.

I am looking for a nice tube warming of the vocal but when I try to apply some nice smooth overdrive I get howling squealing going on.

I'm sure you know what I'm talking about and what I'm doing wrong. Can you please advise me as what I should do to correct the problem, I'll check it out tonight if I get some good directions.

Thanks in advance.