What Have I done? Shorted an amp?


I had two amps that were on (I know) and while moving one speaker connection to another amp, the speaker cables touched the other amplifiers case, sparked, and the amp that was touched, turned itself off, one of a pair Jeff Rowland Model 7, DAMN!

Now, it powers on but I get no sound coming out?

What have I done? At 140 lbs, I don't want to ship this thing around, if it is an easy thing?

HELP!!

Stressed, frustrated, feeling lame, and back to mono,

Dan
Ag insider logo xs@2xporschecab
Check the owners manual for speaker protection circuit or fuse in the amp. It is unlikely that you burned out your amp. A quick touch like that is enough to engage a protective circuit, but probably not enough to burn it out. It is not a good thing to do, but you know that. The Rowland amps are very good and likely would not be permanently damaged by that(hopefully).
Twl -

Thanks for the suggestion. I don't touch stereo gear since I know NOTHING about it! I hate even removing screws, since it would 99.9% of the time mean nothing to me. THAT SAID, this is that 0.01% because after doing what you suggested, sure enough, two blown fuses! I will be heading to the hardware shoppe and making an attempt to replace them. They do look like simple replacements, but I will call Jeff Rowland to be sure these are the right ones in here to begin with!

Sadly, it took me 15 minutes to remove them, being so careful not to touch another wire, in fear of knocking it off its connection!

Thanks again, you have no idea how this has soothed my soul.

D
In my case only output fuse will be blown if such thing take place. I know in Creek amps such event is fatal to an output circuit and even toroidal output transformer(sometimes to be on the safe side the time delay circuitry might be handy)

If changing the output fuse will not change things, here is the simpliest tip you can excersise:

Prior to this excersise I would suggest having a multi-meter and a handy book with specs for transistors set of impedance values between pins(that have to be studied prior in order to presicely detect the defected transistor).

Having the second mono-amp working, you should uncover both of them and compare-test both output stages meaning measuring resistances of output transistors while the both units are off. How you will detect an output circuit? Very simple: you should follow from your binding posts backwards and drow for yourself the points to compare-measure.

For example: you know that the input impedance of amplifier is much greater than the input 10x...100xKOhms VS. 10xOhms.
What if the output reading on your multimeter will show 300KOhms? -- It means problem occured probably with blown transistor.

My first experience on fixing audio/video gear was using an identical unit and the broken unit uncovered and measured. This can be called a "monkey work" but it works.
ALWAYS turns off and unplug your gear before you make any changes of any kind. This will avoid any potential damage to your amp, preamp, speakers, etc..
There are potentially lethal voltages present in much of your gear, I would recommend unplugging and waiting an hour before attempting to change anything in your set-up. Jeff