HOW TO: Change a tube in a TELEFUNKEN ELA M 251E microphone

PROCEED AT YOUR OWN RISK! Tube microphones are fragile and can carry 'shock-worthy' voltages. We are not responsible for the well-being of you or your microphone. Please read all written instructions before proceeding!

BEFORE YOU START:

Turn off your power supply and disconnect it from the power outlet.

Disconnect the microphone from the tube microphone cable and power supply. We recommend leaving the microphone unplugged for at least an hour before starting.

We strongly recommend wearing rubber gloves, like in the video! Grease from your fingers can impact the operation of your microphone.

You will need two small flathead screwdrivers.

If you are uncomfortable with doing this, please contact us. You can always send your microphone in to us to have the tube changed.


USE ONLY 6072A / 12AY7 TUBE TYPE FOR REPLACEMENT

Hold the microphone by the body tube and remove the base ring by turning it counterclockwise until unthreaded.

Slide off the body tube while maintaining light pressure on the two metal side straps.

Push up on the base of the microphone to release the side strap contacts.

Remove the head assembly and the threaded base subassembly.

Locate the four screws and nuts holding together the inner housing plastics.

Use a flathead screwdriver to secure the nut while using another flathead screwdriver to loosen and remove each screw.

After all four screws and nuts have been removed, remove both halves of the housing shell

Lay the microphone flat on a surface, and grip the tube socket with one hand and the tube with the other.

Gently pull on the tube while rocking it back and forth to loosen, if necessary. Be careful not to bend the pins.

Locate the gap in holes on the tube socket and in the pins of the new tube. Angle the tube in to the socket, lining up the gaps.

While holding the socket, push in the new tube so that it is flush to the socket.

Put back on the two halves of the amplifier plastics, lining up the square cut-out with the impedance board. Make sure the metal collar on the base connector sits flush with the inner glove of the bottom of each plastic housing half.

Use a flathead screwdriver to secure each nut while using another flathead screwdriver to tighten each of the four screws.

Locate the two female spring contacts in the head assembly and the two corresponding male blade contacts on top of the amplifier. Line up the contacts and gently attach the head, being extremely careful not to bend the spring contacts.

Locate the screw in the microphone base and the notch in the threaded base assembly. Slide the threaded base assembly over the amplifier, lining up the notch and screw.

Push the contacts at the top of the side straps into the corresponding mounting holes and hold them in place while sliding on the body tube.

Make sure that the body tube pin is lined up with the corresponding notch on the base assembly.

Tightly fasten the base ring back on the microphone.

USE ONLY 6072A / 12AY7 TUBE TYPE FOR REPLACEMENT

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