Disconnecting amplifier speaker.

[jasonm]

Hi,
I'm looking to record electric guitar from the line out on my Laney LC15. However, what I would ideally like to do is disconnect the speaker first by unclipping it from the two speaker clips in the back. So basically the question is - is this safe to run the amp like this or could it damage it in some way?
Thanks

[boingoman]

Yeah, it would probably hurt the amp. Don't do it.

[ggunn]

Originally Posted by jasonm

Hi,
I'm looking to record electric guitar from the line out on my Laney LC15. However, what I would ideally like to do is disconnect the speaker first by unclipping it from the two speaker clips in the back. So basically the question is - is this safe to run the amp like this or could it damage it in some way?
Thanks

Don't do it. For probably more info than you really want...

http://www.w8ji.com/demonstation.htm

This site speaks of high frequency transformer coupled RF circuits, but the same principles apply.

[boingoman]

Cool link. We could used that a month or so ago in another thread.

[jasonm]

Thanks guys.
So what if I were to connect the amp to a load other than the speaker? As long as it matched (8 ohms in this case) it should be fine? I'm guessing that might get a bit hot though.

[Farview]

Yes you can use a load resistor. (not a normal resistor)

[ggunn]

Originally Posted by jasonm

Thanks guys.
So what if I were to connect the amp to a load other than the speaker? As long as it matched (8 ohms in this case) it should be fine? I'm guessing that might get a bit hot though.

Yes, but as Farview says, it needs to be a load resistor. These are usually big, wirewound thingies. Check the watt rating of the resistor, too; it should be at least twice the output of your amp. If you fry the resistor, you probably won't know it until your amp fails due to a short or no load condition.

The safest thing to do would be to get a power attenuator (power brake, hot plate) and dial its output way down so you can monitor the power section of your amp while you are recording.