100 volts???

[Boy Howdy]

I'm considering buying an old tube pedal from Japan. It's marked as a 100 volt unit. Seller says it will work in the US. I must confess I've never heard of 100 volt anything. So what would you guys advise? Should I be concerned at all? I have another pedal like this one but it was originally marketed/sold in the US (though both were made in Japan). Will both sound the same? Will any modifications be required?

I should possibly note that my pedal runs at 150+ volts on the plates (it's a tube distortion pedal).

[52 Bill]

100 or 105 vac is the standard line voltage in Japan. Running it on the standard 120 vac here, I would think may cause problems with the tube and power supply caps. A 20% increase in input voltage will cause a like increase in the secondaries.

What are the voltage ratings on the power supply caps? Can they take a 20% increase in voltage? Is the tube filament running ac or dc, and is it regulated dc? If the filament is running ac or unregulated dc, I'd be afraid that it will really shorten the tube life running that high a voltage on the filaments.

Maybe the power transformer has a few extra taps for different input voltages. Check the one that you have and see what's in there. Or worst case would be to replace the power transformer with one made for 120 vac or use an external step down transformer to bring down the line voltage.

[Boy Howdy]

Thanks, Bill. I think I'll just pass on it. But I appreciate the response.

[R.G.]

Go look at the "Vintage Voltage Adapter" at GEO - http://www.geofex.com.