These block valves are identical in size to the original Aeolian block valves that are found in ALL of the player pianos made by the Aeolian Corporation from 1960 through 1986. However, that is where the similarity ends. The quality and construction of these new valves is far better than those that were mass produced by Aeolian.

There are five major differences between the new blocks and the original blocks. First, the new ones are repairable! The adhesive used to glue the three sections together, while creating a perfectly air-tight seal, is not so strong that the unit is impossible to break apart without causing irreparable damage. Second, the pouches are better. Since the pouch is more air-tight, there is less vacuum loss. This increases the overall efficiency of the player system. Third, the valve stem is lighter. This makes the valve faster, increasing the repetition characteristic of the unit. Fourth, the valve clearance is set to 0.035". As compared to the original units, which were gapped anywhere from 0.040" to over 0.050", the narrower valve gap significantly decreases the transient losses that occur as the valve changes state (from "Off" to "On" and back to "Off"). Fifth, instead of a glued-in nipple coming out to either the left or right side of the block, the nipple comes out in middle. Also, an elbow is used instead of a straight nipple. This allows the user to point the nipple in any direction that is desired, making it 'universal'.

Although the new block valves may seem a little pricey, they are worth every penny. Each valve is thoroughly tested before it is sold. Each valve block is unconditionally guaranteed for five years. And if you are not satisfied with the valve block, send it back and I will send you a refund. Upon request, we will also include Mounting & Repairing Instructions. Also, there is now information on that web page about Testing a Block Valve.