Crown CX824

The difficulty in testing the CX electronics is that the AC power is routed (via the black multi pin connector shown in the above photo) through the tape transport section down to the electronics section. So, I had to rig a temporary way of connecting the electronics to AC with test leads. Once that seemed handled I started on the transport section, removing it from the wooden cabinet and installing it on a rack mounting test assembly. Most of the internal electronics are on drop down frames.




You can see the 4lb capstan flywheel on the left and the drive belt that changes the three speeds. The Crown is a curious mix of electronic and mechanical solutions, the transport has a very effective logic control that allows any combination of commands to be entered. If you're fast forwarding (for example) and press "play" the logic system "remembers" your command, but first engages the braking system, brings the reels to a stop and then engages the"play" function. But, conversely to go from playing at 3 3/4 IPS to 7 1/2 IPS a metal arm is pulled from the front of the deck which moves the belt to the larger diameter section of the capstan pulley. And to go to 15 IPS the deck has to be turned around and manually repositioned on the pulley.

I've been wanting to try using an external playback component with the Crown transport to make an "end game" playback deck for 4 track tapes. But, the bottleneck was the fact that Crown used a hard to find (make that impossible to find) connectors made by the Winchester company. I didn't want to do anything to change the originality of the stock connections but wanted to be able to unplug the electronics and try the de Havilland 222. Lo and behold I finally identified the specific Winchester socket on Ebay and ordered it from Israel. After six weeks shipping time it arrived and I could make up a pair of RCA cables.

This photo shows the rear of the tape transport with the top plate removed and the logic circuit board to the right of center. The main AC transformer is attached to the top plate there is plenty of room to see the three motors.

This photo shows the capstan motor which is a 117v synchronous motor and has a plastic housing to reduce motor noise. There is a fan blade attached to the front of the motor which pulls cooling air over the internals of the motor and exits on the left side.

This is a photo of the transport controls assembly showing the two large DC lamps or bulbs. This deck doesn't have standard mechanical brakes, such as the bands on the Revox for example. Rather a DC voltage is applied to the AC motors which causes the motor to stop spinning. However, more DC voltage is required when the brakes are first applied. So the braking DC voltage is sent through a bulb which as it warms up presents a greater resistance hence decreasing the DC voltage allowing for a gradual slowing down of the motors.

Starting to put everything back together in the cabinet after cleaning the wood and painting the inside bottom which was scuffed. I also installed four feet on the bottom to lift the deck off of the shelf. I've polished and waxed many of the metal chassis plates to restore some of the new look wherever possible.
I was able to replace the main AC power cord and all of the internal lamps.

The cabinet was made by a retired Crown cabinet maker who used solid padauk for the sides and top.