The majority of the equipment we used in our pirate radio station was tube equipment. I think about the only thing solid state was a couple of Radio Shack phono pre-amplifiers that amplified the output of the magnetic cartridges on the turn tables enough to drive the input of the all-tube Gates Yard mixing board that we used.
One of the tube pieces of equipment we used was a Langevin compressor / limiter which did a fairly decent job of crunching the audio down, at least as far as a single band compressor limiter can. We modified it somewhat so that the time constants were as short as possible without severe intermodulation by bass, and we modified the limiting stage so that it only limited on negative peaks and allowed the positive peaks to go as high as they will.
I did a Google search curious to see if any of these old beasts were still around and I ran across, Robert Van Dyke Vintage Audio. He sells all sorts of old tube equipment.
The Langevin compressor / limiter wasn’t among the stuff he currently has in stock but there is still a lot of cool stuff on his list. The equipment he offers for sale is serviceable and might just have a place in your radio station so I’ve added a link to the sidebar.
For those not familiar with tube equipment, there are desirable and undesirable aspects to tube verses solid state.
The desirable aspects is that tubes are very linear compared to their solid state equivalents, and so much less negative feedback is required, and as a result the phenomena common to solid state equipment known as transient intermodulation distortion is almost non-existent in tube equipment. Tubes clip “soft” instead of saturating hard like transistors. As a consequence distortion produced by clipping tends to be lower order harmonics which are audibly much less objectionable than higher order harmonics. In power amplifier applications, tubes amplifiers tend to have lower damping factors and some people (myself included) find this desirable, others who are more concerned with technical perfection prefer an amplifier with a high damping factor to make speakers behave. Tube amplifiers and other devices are less susceptible to radio frequency interference than solid state equipment and they handle overloads better.
The disadvantages to tubes are hiss, hum, poorer frequency response, higher harmonic distortion figures, and they are high maintenance requiring tube replacement, hum balance adjustment, and bias adjustments, among other things. Tubes are less efficient and generate more heat as well as producing less output power for the amount of electricity they consume. Tube equipment tends to be heavy and bulky.
If you’re like me and something that sounds aesthetically pleasing is more important than something with good technical specifications, then you might want to consider vintage tube equipment. I’ve given it up simply because I can’t afford it.