Check out the device that delivers the warm resonance for Adam Curry in his well-regarded podcast. It's the TLA 5052 Stereo Valve Processor. It comes in a channel strip format and it plugs in easily to all sorts of mixing desks. Curry thinks it makes an ideal front end for his system, allowing him to mix down and master his audio on the fly. For me, its analogue VU metering of input level, output level and gain reduction gives an honest look at the potential quality of a sound source.
While most channel strip products provide a single mono channel made up of preamp, dynamics and EQ stages, the 5052 provides two channels of each with independent stereo linking of the compressor, EQ and limiter sections. In mixdown, the 5052 offers full stereo linked EQ and dynamics. This means good things when recording phone conversations or when playing voice mail.
Inside the 5052 sits six triode valve stages shared between the two channels, run from a high quality internal 150V stabilised DC supply. No hums or pops should interfere with your mixes.
Be prepared to pay more than EUR 2000 for this professional piece of equipment.