Anyone used 240V-120V step down transformers?


Hi - I'm new to audiogon and was after some advice. Am thinking of buying a second hand quality amp but want to be able to use it in Asia/UK/Australia. I was looking at maybe a ML335/6 but the manufacturer will only change the voltage over for the Original owner (documents required apparently).

Has anyone tried to run a 110V-120V amp (and other equipment) using a stepdown transformer, and if so, with any success - I was thinking of buying a 2000 to 3000VA toroidal transformer. What brands/ models worked and which ones to avoid? Appreciate any help/tips you could provide.
browsinganch1
I will likely never go back to wall outlets. ALL my amps run through a step-down. I did not want to install dedicated lines for each of my five amps, but had two 240 volt outlets going unused. The simple solution: two step-downs.

Amp one has 1000 beefy watts -- blew all the 8 amp fuses on it the other day, the step-down gave it so much juice (it would max at 20 amps total for the step-down theoretically). Amp two has 2500 watts -- needs loads of current, was always shutting down from the wall (one of its protective functions for lack of current), now the amp will clip before ever shutting down. Amps 3 and 4 -- monoblocks 1600 watts apiece -- sail through anything. Amp 4 for dual 18" subs, never breaks a sweat. can't recommend this route enough. Email if you have more questions.
At that size, I would advise using a stacked iron type. A toroid of that size will have substantial inrush current.

Toroids also have the dubious distinction of having too much bandwidth. A stacked iron type will filter out some of the crud on the AC line, which is always good.

This comes from someone whos uses toroids in all of his designs.............

(Just make sure that you put it far away from all of your gear.)
Wow - thanks for your input. What brand of stepdown did you use (do you have a web link?) and is it toroidal - can you hear any interference in the amp by the transformer? Also, how close to the amps are the transformers - I was thinking of positioning it at the switchbox to the house and then running a dedicated 20A 120V line to the audio room. appreicate some more feedback on this issue. Thanks.
Oh, just want to clarify -- the fuses blew in the one amp due to an extremely taxing dynamic passage of the movie I was watching -- my speakers are low impedence and large and can sop up just about as much current as any amp can provide -- after consultation with the amp designer, he said 10 amp fuses were OK, so I put those in.

The amp is plugged into one leg of the 240v, so is on a dedicated circuit and has a theoretical 20 amp limit from that circuit. The step down has another dedicated circuit as well (the other leg of the 240v), so it can provide 40 amps of current flow to two, three, or four amplifiers.

The fuse blowing had nothing to do with inrush, but there is a big gulp of that when the beast is switched on -- I just always keep mine on. I will email later when I have more time, but I just wanted to set the record straight on those points where I realized confusion might occur.

I mean, you just really got to hear what unlimited juice does for 100 lb. plus monster amps! I've had the second step down installed for five days now -- the last four days I've been giving my ears a rest -- that is a possible downside -- the sound is so clean, so dynamic, so powerful and intense, I think I really over did it! None of the usual clues that it is too loud are there, except your ears hurt afterward! -- that's when you know.
Maich
Which amps ,brands,models,do you have?A lot of amps are 100lbs and some are twice that weight and more
George
Maich, do you know what frequency your stepdowns are putting out? I want to step from 240V/50Hz to 120V/60hz - is it possible to change the frequency as well as the voltage?