Ampeq SVT-450

[Carlosraj]

Hi


A friend send me this amp with a power failure problem. Upon checking, I realised that the toroid power transformer has blown. I am trying to order a replacement toroid transformer, but I am not sure of the power rating(VA) and secondary voltages of the transformer. The schematic shows rectified DC voltages of +64V and -64V. Then I guess the secondary center tap AC voltage should be approx 45VAC -0V - 45VAC. Can someone advice what should be the secondary AC voltages and the power rating of the transformer.


Thanks

 

[bullittstang]

If your schematic is correct and you need +/-65Vdc, then yes, I would get a dual 45V secondary toriodal, or a center tap (45-0-45).

Assuming it's a 200/watt @ 8r and and approx 350/watt at 4r and it's a 2-channel amp - I would get a 800-1000VA toroidal. Some would say to go to a 1500VA, but I have never listened to any 200-350/watt amp at clipping in an actual room and not destroy the speakers (or my ears) first, so I think 350+350+20% margin would be adequate.

Also - make sure you measure to ensure the new toroidal will FIT!!!

 

[Carlosraj]

OK, thanks

 

[JonSnell Electronic]

Don't forget the + - supplies for the low voltage section, you may need a small toroid to run those!
Take a look here;
Toroidal Transformers | RS Components

 

[PRR]

Weigh the old lump. Pick a new lump of similar weight.