Reply To: A3 – what are the latest updates for backplates ?

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#277
John V
Participant

Hello Supportmac,

Attached is a wiring diagram for the Toroid II transformer along with a few pix. of the Connsumate Backplate.
A couple of notes:
1. The resistors and capacitors for the high frequency filter of the Toroid are as follows:
Resistors: 4 Dale 48 ohm 50W 1% non inductive wired in parallel to
give a net resistance of 12 ohms.
Capacitors: 3 8ufd Audiocap Theta’s wired in parallel for a
total capacitance of 24ufd.
2. The midrange filter is the coil box shown in the diagram. Note that there is a separate 15 mhy iron core coil wired in such a way to give 20 mhy with the 5 mhy coil in the module.
3. The values of the high voltage mixer have changed over the years.
Currently the value is 2.2 nfd. I’ve attached a diagram showing how to measure the value.
4. The bias supply is now a regulated unit so that variations in line voltage will not affect the bias level of the panel.
5. The Bass transformer has not changed over the years so you should be able to use the existing one.

I’ve also attached a few pix. of the current backplate

The resistors and capacitors are available online. The other parts, transformer, coil, mixer, bias, switches, new blank backplate, can be purchased from the factory. I would call Connie and discus it with her or you can email Roger.

Should you have further questions don’t hesitate to ask.

Good Luck,
John

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