• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

240v to 110v for Sun Valley JB-300B

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I need to know what wattage step down transformer I need for a Sun Valley JB-300B valve amp (110v) from Japan. stepped down from Australian 240v. Also any information on it would be good, as there does not seem to be a lot on the net as far as I have found so far.
Any help appreciated

Cheers
Pete
 
Did you try to check one of the PDF available ? Though I cannot read japanese, I can still calculate the power needed by the transformer by simply looking at the voltages + max. ampere for each coil.

You might need a step down transformer which can handle about 220 VA ;)

Best regards,
 
Administrator
Joined 2004
Paid Member
As tubetvr points out Japanese mains voltage is 100V and is commonly 60Hz (although 50Hz is or was used there too). Make sure that the amp's power transformer can operate on 50Hz (probably not an issue)

Growing up overseas we commonly used 1kVa auto-transformers to power loads of up to about 400Va which maintained better regulation that a smaller sized transformer would under varying loads.
 
50Hz is used in Eastern Japan like Tokyo and 60 Hz in Western Japan like Osaka.

The issue with voltage being 100V in Japan and not 120V which is standard in US is often overlooked and sometimes result in problems, In Japan they sell transformers for 100V in and 120V out for driving sensitive equipment built for 120V.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.