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100-120 / 230-240

Posted: Fri Nov 09, 2018 10:48 pm
by Chrisvinnies
I opened a small live music venue last week and provided a TH30 as part of the back line along with an AD200. Love these amps!

Anyway last night I caught the sound tech switching the TH30 from 230-240 to 100-120 to as he quoted to “Reset it” as the amp had lost power. I’m pretty sure it would have been a fuse as it was seated a little weird. We live in Australia so it should be 240.

I’m on my way to pick up a new fuse today but wanted to know if any permanent damage would have been done from switching from 240 to 120?

Re: 100-120 / 230-240

Posted: Sat Nov 10, 2018 12:33 am
by Jondog
It’s definitely not a reset button :lol: Not a good idea to switch it plugged in and it should be set at 240. If tbe amp had no power going to it when it happened, probably ok. If the HT fuse or mains fuse is blown, find out why.

Re: 100-120 / 230-240

Posted: Sun Nov 11, 2018 11:40 pm
by fiveightandten
Did he turn the amp on?

Depending on whether or not the standby switch was set to on, or how long the amp was energized, that could cause quite a bit of damage.

100V or 120V mains primary winding will raise the internal voltages significantly more than the 230V or 240V setting. So when switched to the lower position, it could over run every component in the high voltage supply, and over run the tubes.

P.S. Get a new sound tech.

Re: 100-120 / 230-240

Posted: Mon Nov 12, 2018 1:58 am
by Sooner
I was working at a venue once when the technician accidentally set up a temporary power panel for 240V instead of 120V. The show was cancelled when all of the band's amps got fried when they turned them on. It was an expensive night for the venue owner...

Re: 100-120 / 230-240

Posted: Mon Nov 12, 2018 2:44 am
by trossit
You might consider verifying the voltage input select switch is in the proper 230v position for your country then place a piece of clear tape over so it can't be changed (or reset?). :shock:

Hopefully the fuse had already blown prior to your sound tech switching this selector to 120v. You may want to smell the amp to check if there is an odor of burnt fiber-glass (plastic)...meaning something on the printed circuit board got hot and burnt a trace off the board. Sometimes PCB traces act like fuses.... :wink:

Truly hope it was just a bad fuse...or maybe a faulty line cord.