Lowrey Heritage DSA
I acquired this organ at the start of 2020 from a friend. I have always coveted the Lowrey Heritage Deluxe DSO made famous by the likes of Alan Haven and this DSA was a predecessor. Although it has all of the same tone and solo tabs of the DSO, it lacks AOC (Automatic Orchestra Control) and an internal Leslie. The Leslie is not a problem as I use a 145 or 147 with it as most professional organists did.
The organ was in very good cosmetic condition but as it had not been played for 30+ years it was not a wise idea to turn just it on and try it out.
Internally things were not as good. An electrolytic capacitor had failed and taken one of the Candohm/Muter high wattage resistors with it as I found after replacing all of the electrolytic capacitors and switching on. The high wattage resistor glowed orange whilst emitting smoke. A modern replacement resistor was sourced and for the first time the organ could be played and tested.
Many of the tones did not play ie certain footages on certain keys were missing. In 95% of cases this was down to broken neons. These are used on the sustaining note keying and light up and conduct when they receive a voltage that exceeds a specific threshold. With age, the legs break off and render the associated tone silent. I ended up replacing nearly a hundred of them across the tone generator panel. This included pedal notes that were missing.
A lot of the switches had intermittent faults. A blow through with compressed air whilst holding the vacuum cleaner hose close followed by liberal amounts of contact cleaner cleared up the issues.
Another major fault was the pedal burble which can be broken into two separate issues. First of all the notes did not cancel each other. As they are supposed to be monophonic this meant that if a note did not cancel it would make the subsequent note played gurgle. A good clean of the pedal generator circuits with Isopropyl Alcohol and a brush followed by rerouting of some of the wiring solved this problem. The second issue was that when pedal sustain was used, the decay of the note would sound like an explosion. This was found to be down to the sustaining neons in the pedal assembly firing at random. Despite the reason for this being widely blamed on dampness and humidity, I discovered that in fact the busbar voltages were too high due to failures in the voltage divider network. I replaced the guilty resistors with higher wattage versions because this appears to be a design fault. I know of two other models with exactly the same symptoms and cure.
With all of the above completed, all that remained was to install a Leslie connection for my 147 or 145 and the work was complete.
Lowrey Heritage DSA Pictures