Re: Peavey Rockmaster.... amp?
There was a Rock Master preamp, and as you can see these were very popular.
There was also a Rock Master head. This was a hybrid amp; with a SS front-end with a 4x6L6 power section rated at 120 watts rms. There was a single set of tone controls, and the Peavey Saturation control for distortion was footswitchable. No reverb, but it had a simple patching loop. The Butcher and the VTM 60/120 amps followed the Rock Master--I believe both of these were all-tube models.
The other amp in this series is the one you may be more familiar with: the Road Master. It featured two separate channels and had a compression circuit built in. It was a ferocious beast, with a 6x6L6 160 watt rms power amp. This was the successor to the Mace amp.
The Rock Master amp is certainly a seviceable amp for those who need a lot of clean power, and want to augment their tones with pedals. They have a slightly attenuated top-end compared to the Fender and Marshall amps of the day, with a punchy mid-range characteristic of many of the Peavey amps of this era.
In my experience they are very durable, and can often be found for very good prices. I owned one nearly twenty years ago, and still regret selling it.
Bill