moving to Europe,need help with converting 110/220

Things like amps (and your sub) should run fine off a step-down transformer...the 50 Hz difference is only a concern for things such as turntables that use the power line frequency as a speed reference. I ran my Velodyne HGS-12 just fine off a transformer.

I moved from the States to Paris 3 years ago, and was faced with the same problem (110V gear running on 220V). Fortunately some of my equipment (Quad and Revox) is multi-voltage, no problem there. The rest is 110V equipment, Including two 200W/channel power amps. I simply purchased a 2kW 220V/110V line stabilizer transformer (~$200). You can purchase the equipment from www.eastwestintl.com or www.220voltappliances.com. The other thing to remember is, HiFi equipment in Europe, especially high end gear, is a lot more expensive then in the USA. Bottom line, bring your equipment with you and use a voltage stabilizer step down transformer to run it.

However, one thing to consider, and I learned the hard way. Certain US high end manufacturers (Krell for certain in the last ~10 years, and, I believe Martin Logan and others) put a frequency sensing chip on the power input circuit. This senses if you are running 60Hz (US) or 50 Hz (Europe) mains voltage (irrespective if it is transformed down from 240/220V to 110V and will not work if the power source is 50Hz. Krell in France charged me $180 to have my Krell HTS converted when I experienced this problem. Check before you leave!

Yes, check before you leave, but several manufacturers are making their gear so that it is either dual-voltage (no change necessary), or can be simply switched internally. Why? Simple, makes life a lot easier for them since they ship all over the world. For example, Cary tells me their CD players have 4 fuse slots. 2 for 110v and 2 for 220v. All you do to change to the correct line voltage is move the fuses. Musical Fidelity tells me their gear (bought it here for taking overseas) is easily changed internally - no technician required.

So, do check with the manufacturer before using a transformer. I have also used transformers, and they work fine, but some of them (even the more expensive ones) put out a rather loud hum.

Good luck!

Thanks guts for your reponses.I am a little bit afraid of the hum when using transformer,I purchased a biggest 5000w tranformer/voltage regulator they've had hoping it will make a better job.I just found out that my Revel b15 sub needs only cahnge a fuse and my english tube needs some simple internal switch so only TV projector and some small devices will be used through the transformer.Thanks again