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previous: Charlie Why is it a bad idea to run a tube ... -- 3/28/2000 1:48 AM

Re: no speaker load

3/31/2000 4:08 PM
Doc	Re: no speaker load Some amps, like the typical Fender, use shorting type speaker jacks which tend to prevent OPT damage if no speaker load is plugged in. There would be a problem if the cord was plugged in and the speaker wire or voice coil lead open circuited. It's better than a non-shorted jack, but it's not failsafe. It's good insurance to simply wire a 250 ohm /5w resistor permanently across the output transformer secondary (inside the chassis). This will limit the induced flyback voltage to a safe maximum, and not absorb any real power when paralleled with your speakers.

3/31/2000 4:08 PM

Doc

Re: no speaker load

Some amps, like the typical Fender, use shorting type speaker jacks which tend to prevent OPT damage if no speaker load is plugged in. There would be a problem if the cord was plugged in and the speaker wire or voice coil lead open circuited. It's better than a non-shorted jack, but it's not failsafe.

It's good insurance to simply wire a 250 ohm /5w resistor permanently across the output transformer secondary (inside the chassis). This will limit the induced flyback voltage to a safe maximum, and not absorb any real power when paralleled with your speakers.

Replies:

Don Schultz Hello again Doc,Wou... -- 4/10/2000 3:16 PM