I use one as a pre amp and set on low distortion gain to get that extra clunk for more extreme metal sounds.
I have the cheap 1980`s Ibanez model. Does anyone have a more expensive 1970`s one ? or another pedal that they like to use as a pre amp in a similar way ?
This isn't 70s like you asked for, but I've always been a big fan of the BB Preamp pedal because it doesn't strip out your lows on you and has independent bass/treble knobs. The new one has a mid knob on it too. Sounds great on it's own as well, but it's a bit pricier than most tubescreamers.