If you just need the bass boosted and have cone speakers get a space tech Lab vsub 100, it's not a subwoofer but it boosts the bass. At least look up a few reviews on it, most reviews say that it sounded better than any subwoofer they ever had. I have a few pieces of space tech equipment, and the designer Al will tell you if it will work with your system, he has always been a straight shooter with me.
Any High End Tube Preamps with *gasp tone controls?
After dropping in a vintage Scott 222C into my system while my amp was out for repair I'm really missing the tone controls now that my amplifier is back. It seems sacrilegious but I just can't get the bass where I want it without a bit of boost plus I'm sure my hearing is changing as I get older so why not be flexible... even if it results in me being thrown out of the audiophile club.