For the X5 Hammond, Leslie designed the monstrous 760, but also the much smaller 825. The 825 still packed some serious punch, with a 70-watt amp feeding a special speaker (this one has a 1977 date code - 3rd week), but only had the rotating foam drum under the downward-facing 12" speaker, without the rotating horns, and was designed as the 'portable' Leslie for smaller venues.
Of course, guitarists jumped onto this model, and it soon became dubbed the 'guitar Leslie', some even claiming (wrongly) that it had been designed specifically for guitar. Nevertheless, the 825 was perfect for guitar use, as it had its own 2-channel 'Combo' pre-amp and control unit, which could be fed directly from a guitar, from a bank of pedals, or even from the line-out of a guitar amplifier.
In about 1977, the 825 was updated to become the 820 model. The main difference was the change to the 11-pin system that had become a Hammond standard by this time. In practical terms, this meant the power cord was fitted to the speaker box itself, rather than the pre-amp, making it a little more user-friendly. 11-pin B-3 clones can plug directly into the 820 without using the Control Unit / Pre-amp, but most use these remarkable Leslies for amplifying 'single channel' keyboards or guitars. The Leslie Combo Pre-amp III has two mono channels which each utilise a standard 1/4" jack, and each have their own gain and tone controls, so two guitars, two keyboards, two accordions, or any combination of any other amplified instrument can be fed and in maixed for the correct balance. For a guitarist, you can put any pedals you like in front of the unit, to taylor your own sound. I can assure you thet NOTHING sounds as good as a genuine rotating Leslie when you want that particular 3-dimensional sound. No pedal comes close! Truly amazing.
The pre-amp/control unit has become quite sought-after in its own right, and it is rare to find a Leslie 820 complete with its original matching Combo pre-amp III and 11-pin connector lead, but that is exactly what we have here. It's also a rare, original 240 volt model (not in imported American 110V model requiring a step-up transformer), so is ready to use.
This unit is in remarkable condition for its almost 25-year age. There is some scuffing to the black tolex covering on the plywood cabinet, and the grilles (there are three) are not as pristine as the day they were installed, but overall the unit is in great condition. The Combo Pre-amp is remarkably free of wear and scrapes.
Other than some basic cleaning and checking, the unit required no further work, and it's ready for another 25 years of service!
These are very sought-after, and I doubt it will last long. Hesitate at your peril!
Sold to Jon