Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Jalmeida on September 20, 2023, 12:23:02 pm

Title: Speaker jack speaker loads
Post by: Jalmeida on September 20, 2023, 12:23:02 pm
Hello,

I am building an AC30/4 in head form and was curious about adding some sort of speaker load so if a speaker isn’t plugged in I won’t risk blowing the OT. Perhaps a switched 1/4” switchcraft jack with a 8R load resistor. Never seen this or done it myself so thought I would bounce off the braintrust here. Thanks.
Title: Re: Speaker jack speaker loads
Post by: sluckey on September 20, 2023, 12:29:54 pm
That will provide protection if the speaker cable is unplugged from the amp but offers no protection if the cable is unplugged from the speaker cab. Some amps put a 200Ω resistor across the speaker jack such that the resistor is always connected. This provides some protection, better than an open circuit.
Title: Re: Speaker jack speaker loads
Post by: PRR on September 20, 2023, 12:33:56 pm
...Perhaps a switched 1/4” switchcraft jack with a 8R load resistor. Never seen this...

H-zog