500W PA amplifier with Limiter

[sekhar]

rhodrich
u cant run b500 in bridge mode @ 4E . if need 2 drive b500 at bridgemode lower the voltage rail and run @ 8E....

regards
sekhar

[engel dela pena]

Originally Posted by apexaudio

B500 based on schematics of H900, but in AB class.
Power supply +/-90Vmax.

apex said +/-90v dc

[engel dela pena]

and supply drops +/-10v underload

[engel dela pena]

how many reservoir caps can i use?
i see many builder using 4 pairs of caps or more,
how is that? the more the merrier,

[Mamak]

Originally Posted by wg_ski

If you use a light bulb limiter, you don't need to step it down first or use any DC protect. The light bulb is actually better than a variac. A lot of amplifiers will work perfectly at lower voltage and get unstable at full voltage. With a variac turned down it may behave, and then go bang very suddenly as it is brought up. The light bulb will let the amp get to 90% of normal voltage when it's idling, and bring it down automatically if it goes unstable.

sorry i dont understand.why use bulb?
amplifier just use example -+70v.how the connection of bulb with this amp?

[smartx21]

A series light bulb, like this:
Light Bulb Current Limiter

Regards,
Max.

[apexaudio]

Originally Posted by rhodrich

@ apex

Sir if b500 will be bridged at 77+- vdc because. i have trafo 55 0 55 2000va and loaded with 4 ohms. i think i will end up burning my amp. i will have peak to peak voltage of 154 then try loses or voltage sag to 134vdc p-p. so the amp power would be 4489 watts at 4 ohms. if the power is continues the current 33.5A. if it is possible to do this way how many trannies needed? maybe need to used mjl4281 bec. have higher voltage rating than 2sc500.
pls. comment sir apex about this. thanks alot

You need add predrivers (post #967) and use 7 pairs of outputs for 4 ohms load in bridge mode.
Regards

[rhodrich]

[QUOTE=apexaudio;2388456]You need add predrivers (post #967) and use 7 pairs of outputs for 4 ohms load in bridge mode.
Regards[/QU

thanks alot sir.

[AndrewT]

Originally Posted by Mamak

sorry i dont understand.why use bulb?

it prevents you blowing up your amplifier if you have made a mistake wiring it up.

[Mamak]

Originally Posted by apexaudio

1,2 - two pairs 2SA/2SC with +/-56V you will get about 120W/8R (resonable THD)
Regards

apex.b500 need step driver or not?or step driver only for h900?i still collect enough information to build this amp.i want to drive car subwoofer speaker.