Bass reeds slow to speak

[Organfella]

Remember yours is a pressure organ so creating a vacuum to sound the reeds means the airflow is opposite that of the action assembly. I would say a tank with compressed air and a control valve would be more appropriate. for this one could use a tire pump with suitable tank. But be careful - those reeds do not need a high pressure to sing and any excessive pressure may cause damage. Another way to test is the lips, you know, the kissers - sucking and blowing gently in turn but it will only work on smaller reeds as not all of us have big bass kissers... 😊
Nico

[Coenraads]

Suggest staying away from any source of compressed air. Remember, tire pressure of 30 lbs/sq. in. will support a water column around 70 feet high. Organs work with pressures of around 3 inches of water. You need volume, not pressure. I use a small (clean) shop vac working in reverse. Building a pressure regulator is easy. Drill a one inch hole in the top of your test box and cover it with a slat of wood hinged at one end. Excess air pressure will push the slat up to release the pressure, and a weight on the slat can be adjusted back and forth to get the desired pressure.