Eden WT-300

[clintronics]

I have an Eden WT-300 amp that works fine but the output limit light comes on at 31VAC RMS or 240W @4ohm if my calculations are correct. Does this amp have a problem? Its rated 300W@4ohm. I've had Mesa tell me plus or minus 30% is acceptable.

[Robert M. Martinelli]

Hi,
your calculations are correct, but.....
Are you measuring the RMS power by playing through the amp and taking your readings across the speaker or are you doing it on the bench using a 4 Ohm dummy load instead?

I'm asking this because the dummy load, being a resistor, has the same impedance over the whole spectrum of frequencies, while a speaker's impedance is not constant.

Another scenario : The overload protection circuit's threshold could be set too low and the limiter could trip at a lower power.

300 W RMS on a 4 Ohm dummy load means you should be able to get some 34.6 V(RMS) across the load's terminals. Anyway, keep in mind that from a "sonic" ( SPL ) point of view, all other factors being the same ( speaker, cab etc. ) with some 240-250 W you're only less than 2 dB away from the amp's maximum SPL, so it doesn't make much of a difference IMHO.

Nonetheless, I have to disagree about the fact that being 30% off the rated power is to be considered "normal". This means I could sell ( or advertise ) a 40W RMS amp as if it was a 60 W RMS one, and that could be hardly considered fair IMHO.

Hope this helps

Best regards

Bob

[clintronics]

Dummy load

200hz into a 4 ohm dummy load.

BTW im not making up the mesa story. I had a 2 6L6 amp that was putting out 35watts and mesa told me that was OK because there was so much margin of error because of the many people they had making OP transformers for them at the time. This was 10 years ago when I used to do warranty work for them.