toroidal transformer rating

[djdamix]

which VA and VAC ratings do you advice me to do à 300W @ 8 ohm audio amp ? The first i've made (thanks to this forum) need 2 x 35V to give about 90w @ 4 ohm. What's the formula to get these parameters ???

I think almost all the loss are in the output state (MOS) ??

Thanks

[UrSv]

Too little info. Type of amp (Class A Single-ended, Class A PP, Class AB, Class D etc...). Preferably type/schematic...

[djdamix]

sorry ... it's class AB output stage, IRFP240 (MOS). I have not the schema yiet ...

David

[djdamix]

(and of course IRFP9240 also )....

[sss]

for 300W amp u need about 500VA transformer

[djQUAN]

Originally posted by UrSv
Too little info. Type of amp (Class A Single-ended, Class A PP, Class AB, Class D etc...). Preferably type/schematic...

well, I just thought that class A would be out of the choice. 300W RMS with 20% efficiency?

[djk]

60-0-60AC will give ±85V no load, 500VA is good for me.

[UrSv]

Originally posted by djQUAN


well, I just thought that class A would be out of the choice. 300W RMS with 20% efficiency?

Hey, asuming too much here. He might be using this in his winter cottage in Greenland where he has his own power plant. Besides, the question is hard to answer if no information is at hand....

[MikeW]

Check out Rod's subwoofer amp.
http://sound.westhost.com/project68.htm