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Problem with ampeg svt pro 4

Discussion in 'Amps and Cabs [BG]' started by iogaztelu, May 11, 2005.

  1. iogaztelu


    May 11, 2005
    I bought an ampeg svt pro 4 in the USA and I have a problem with the voltage because in the USA is 120VAc and in Spain 220VAC. So I contact with ampeg and they told me that I have to cahnge some capacitors but I haven´t got any schematic. What can I do?
  2. Hi, I had a simular problem, was looknig at improting an SVT 4 from the USA- Ampeg told me to contact a dealer- they are able to make the change over for you- I cant imagine it being all that complex so it shouldn't cost that much, you should get to keep warrenty too, if you go through a dealer.

    That is of course there is one in Spain...

  3. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    For SVT4PRO, older USA units that you might buy used on ebay, etc, may be 120V only. Anyone outside the USA needs to think about that when buying a used amp from USA.

    New USA units use a universal transformer and can be re-connected for any of the various normal mains voltages from 100VAC to 240VAC.

    Of course, units originally made for export can be re-connected for the other voltages also.
  4. hugo5


    May 1, 2005
    did you consider to use an outside transformer 120/220V, they are not that expensive.
  5. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    There is another problem.....

    The US mains are 60Hz...... european are 50 Hz.

    The 60 Hz transformer won't work well on 50 Hz, if it works at all (although a 50 Hz transformer will work fine on 60 Hz). The lower frequency demands a transformer with typically more iron, certainly more "primary inductance".

    The result is that a 60 Hz transformer may overheat and fail if used on 50 Hz. Or, it may blow the fuse at higher power outputs. In extreme cases, it may simply blow the fuse.

    These problems will be helped a little if you run it at a lower than normal voltage, say 10% low.

    Theoretically, you would use 5/6 of "normal" voltage, but that may not allow the unit to work. So 10% low gives you some margin while probably continuing to work, although at lower than nominal power.

    Again, when buying off ebay, be sure that the unit in question, no matter who made it, can run on your local power.

    In the case of Ampeg, any originally exported unit will run at 50/60 Hz, and will run at 120V as well as 230V or 230/240 V.

    But NOT all OLDER domestic USA ampeg units will run at 240V 50Hz.

    Newer Ampeg virtually all run at world voltages.
  6. flange


    Feb 22, 2005
    Cochrane Alberta
    You could also get a furman power conditioner that will
    adjust the voltage to an appropriate level. I can't say for
    sure but I think it should also take care of the frequency mismatch. Problem is it won't be cheap but it is excellent protection for your gear
  7. I got my SVT II recently, and when i looked at the back and inside one of the big transformers had been changed and it didnt have the removable power chord, so i dunno how much that set the guy back, but i spose it is possible to convert the older units

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