500W PA amplifier with Limiter

Noerhakim · 2011-02-26 1:58 am

Hi Miles....
for one pair of output and dc voltage + / - 40v, what are the changes?
thank you sir

wattaniya · 2011-02-26 1:40 pm

to check the amp in full volume without speakers using 500w bulps in amp out is it correct?

apexaudio · 2011-02-26 1:53 pm

nazirdigi said:
to check the amp in full volume without speakers using 500w bulps in amp out is it correct?

No, use resistors for shunt on output for test. Bulps is NTC resistor ( 0,1R cold and 2,8R when light at 12V for 50W bulp), useless and danger to connect on amp out exsept in series with speaker for protect.

apexaudio · 2011-02-26 1:55 pm

Noerhakim said:
Hi Miles....
for one pair of output and dc voltage + / - 40v, what are the changes?
thank you sir

Use 1k/2W instead 2k2/2W for R24 and R25.

wattaniya · 2011-02-26 1:58 pm

in the pcb there is r24 and r25 4.7k/2w resistor why is that.

Noerhakim · 2011-02-26 2:00 pm

apexaudio said:
Use 1k/2W instead 2k2/2W for R24 and R25.

how many watts of output?

apexaudio · 2011-02-26 3:42 pm

nazirdigi said:
in the pcb there is r24 and r25 4.7k/2w resistor why is that.

4k7/2W is only for test with +/-90V rail.

apexaudio · 2011-02-26 3:42 pm

Noerhakim said:
how many watts of output?

120W/4R with +/-40V DC

Noerhakim · 2011-02-26 3:48 pm

apexaudio said:
120W/4R with +/-40V DC

I plan to use this circuit for powered speakers, 3 pairs of outputs for low and one pair of outputs for high (8 ohm speakers)

AndrewT · 2011-02-26 5:00 pm

Noerhakim said:
I plan to use this circuit for powered speakers, 3 pairs of outputs for low and one pair of outputs for high (8 ohm speakers)

120W/4r tells you a channel can drive a 4r0 load to 120W.

If you attach a group of speakers to that one channel then the effective impedance of the group of speakers must not be less than 4ohm.

engel dela pena · 2011-02-27 6:43 am

R24 R25 summary
+/-40v dc 1k2 2w
+/-55 1k5
+/-80 2k2
+/-90v dc 4k7 2w

yohnsee · 2011-02-27 2:56 pm

Hy Apex! One more question: how much voltage will drive the B500 to its maximal output? Will line level (0.7V) be enough, or do i need higher voltage?
Thanks

apexaudio · 2011-02-27 6:52 pm

yohnsee said:
Hy Apex! One more question: how much voltage will drive the B500 to its maximal output? Will line level (0.7V) be enough, or do i need higher voltage?
Thanks

Line level 775mV is enough to drive B500 to maximal output power.

yohnsee · 2011-02-27 7:20 pm

apexaudio said:
Line level 775mV is enough to drive B500 to maximal output power.

Thank you, next time i post the pictures of the completed amplifier.

daveinsingapore · 2011-02-27 8:45 pm

BX500 pcb layout

apexaudio said:
I cosidering to add signal led, fan control, VI limiter, triple darlington...

hey Miles...any luck with that new PCB layout for the BX500..with all the extra's on it..I have been trying to make it all fit and can not ..yet...please have you redesigned the PCB yet....please post..I wanna make the BX500....with the extra's...thanks..

suryadi5417 · 2011-02-28 11:04 pm

sorry, mr.Apex (Mr.Mile) this psu for one channel(mono) or Channel(stereo) on #54. thank's. Regrads

apexaudio · 2011-03-03 7:26 pm

Stereo / Bridge Mono

This circuit can be use to switch any stereo amplifier to bridge mono mode.
BX500 have balanced input, but without bridge option, use this circuit if you want use BX500 in bridge mono.