Safety First – For European Owners of Imported Vintage Guitar Amps from North America

I was having an email discussion with a friend in the USA who had an original Blackface Fender Super Reverb amp. So it is obviously pre 1969.  Ams of this era oonly have a live and neutral connection and no earth ( ground) connected on the powerline. There is a switch on the back of the amp which optimises the ground for noise BUT it is not a true ground ( earth) for the metal chassis. these Nort Maerican domestic market amps run on 117 volts AC at 60Hz.  Vintage amps fromn the USA are offered on well known auction sites and are sold by some Music shops. As Europe is 230 volts 50Hz, there are some items to keep in mind. First of all, most folks know that you need to use a step down transformer to generate the nominal 110volts AC. However on the very old amplifiers they use paper insulation and they were never designed for 50Hz and they can overheat when used in Europe. Check out with whoever you are purchasing from that they will give you a gurantee that the transformer will operate safely on 50Hz.  This becomes more important with the oldest amps from the 1950’swith paper insulation. You don’t want your valuable investment to become an on stage smoke generator!
Also, I would recommend that the amp is modified to have a proper earth ( ground) on the chassis. This is for your safety. you can get a good shock from a valve amp when for eample you touch the microphone which is connected to an earthed  ( grounded) P.A. amp. I talk from bitter expereience!  You can tell this by looking at the USA power cord. The old amps only have two cores in the power cord  going to the power plug and th erplug has two prongs. An earthed ( grounded ) amp  has three wcores on the power cord.  If you have access to a multi-meter, check that the biggest pin on the USA power plug is directly connected to the metal chassis. It should read zero ohms and definitelly less than 2 ohms.
Also make sure that the transformer earth ( ground) you are using to convert the 230 volts to 100volts does have an earth ( ground) connected all the way through from the 230 volt earth to the amp chassis.. You can do this with a multimeter again from the earth pin on the step don transformer to the amp metal chassis
Play Safe !