REL subwoofer with old McIntosh tube gear?

I use a REL with a tube amp and lifted the ground on the REL (This model, Q150E, has a switch for that). Humless! I also use a PS Audio Humbuster III on my power amps, so there's that.

Thanks Wolf...what does 'lifting' the ground mean?

Lifting the ground is using a two-prong adapter on the end of your power cord that 'disables' the ground plug. Also, try using a Hum X by Ebtech. You could also try attaching the REL ground wire directly to the chassis of the amp instead of the speaker post.

I have had a REL Storm III with a McIntosh MC275 mkIV. Was wired from the speaker terminals in the amp into the REL, as the preferred method by the manufacturer. So this is bass reinforcement at the lower levels. The amp still try to reproduce the whole spectrum. I was very happy with it.

Having said that, I replaced the ReL with two Rythmik subs and I'm happier, and I'm thinking it might be best to have a crossover between amp and preamp so to avoid the low freqs from getting into the amp and let the subs reproduce them.