500W PA amplifier with Limiter

[A square]

hi

Hi,
if you have a balanced source fed in through an XLR plugged cable then you don't need a bridged switch. Each half of the amplifier will be driven by the hot or cold input pins.

Read Rane, Jensen, D.Self, ESP.

hello sir

thank u for this sir.

 

[apexaudio]

hello everyone pls help me for XLR input with stereo bridge switch

This is simple XLR input circuit.
I suggest to use 2 way x-over with XLR input, and 3 position switch to select input mode (subwoofer, satelite or full range)
Regards

 

[apexaudio]

if the clip LED illuminates on a very fast transient, can it be seen?
How long does the transient have to last for our eyes to see the light?

Do we need a timer to hold the LED on for maybe 1ms?

Clip LED light 10V before amp clip, that give visualable time light.

 

[AndrewT]

Clip LED light 10V before amp clip, that give visualable time light.

How do you know whether a 1us clip or a 100us clip or a 10ms clip gives a visual warning?
I don't know.
Maybe a prolonged series of 100us clips are visible, again I don't know.

I suspect some form of peak hold is required to show fast transient clipping. I seriously doubt that short clips will be visible without a peak hold facility.

For comparison purposes, a half wave of 20kHz is only 25us duration.
If only the top half of that half sinewave triggers the LED into conduction, then that gives rise to a 12us clip indication. Can we see that?

 

[sekhar]

miles help me with this when using 12 o/p pair wat should be the driver transistor be MJE15033/32
or should I use the O/P transistor as driver ........ plz reply soon

regards
sekhar

 

[AndrewT]

reactive impedance filters back through the stages.
If a 12device output stage is required to provide sufficient SOAR then the driver/s must also be designed to survive that reactive loading.
1pr of cold To220 are unlikely to have adequate SOAR to drive that many hot outputs.

 

[apexaudio]

miles help me with this when using 12 o/p pair wat should be the driver transistor be MJE15033/32
or should I use the O/P transistor as driver ........ plz reply soon

regards
sekhar

Use this output stage for more o/p pairs,
Regards

 

[sekhar]

can i add the vi limiter in b500 shown in the picture................



regards
sekhar

 

[AndrewT]

the V part of VI limiting has been omitted.
You need to check a working VI circuit and then modify the component values to suit your amplifier.

 

[apexaudio]

can i add the vi limiter in b500 shown in the picture................



regards
sekhar

Use this MACKIE schematic for VI limiter (value for 2SA1943/2SC5200)
Regards

 

[sekhar]

i am falling asleep ..................................
here is a sneak peek of the updated pcb still a lot of work to do will update tomorrow ....................and pcb size finalized 300mm X 68 mm..... max can be a bit less......





regards
sekhar

 

[engel dela pena]

i am falling asleep ..................................
here is a sneak peek of the updated pcb still a lot of work to do will update tomorrow ....................and pcb size finalized 300mm X 68 mm..... max can be a bit less......





regards
sekhar

sekhar
wake up buddy
time to work

 

[andrewlebon]

hi apexaudio
greetings should R23 BE 680 OHMS or is 330 OHMS correct will
MJE340 MJE NEED heatsinks
thanking you
andrew lebon

 

[apexaudio]

i am falling asleep ..................................
here is a sneak peek of the updated pcb still a lot of work to do will update tomorrow ....................and pcb size finalized 300mm X 68 mm..... max can be a bit less......





regards
sekhar

Track mising

 

[apexaudio]

hi apexaudio
greetings should R23 BE 680 OHMS or is 330 OHMS correct will
MJE340 MJE NEED heatsinks
thanking you
andrew lebon

For BIAS setup R22 should be 1k2 instead 680R for triple darlington output stage, and R23 is correct 330 ohms.
Q5 (MJE340) must be on main heatsink with outputs.
Predrivers MJE340/350 can use smal heatsinks, but no need.
Regards

 

[thunderjets]

Hi Mr. Mile

i have built B500 in bridge mode, i use 1800va transformer ,rail voltage 63+/- vdc(45ct45) . caps 6 x 10.000/100vdc. are those caps enaugh for this ?

 

[sekhar]

ok frnds so i am up good morning every one ...............................



regards
sekhar

 

[sekhar]

miles can i use the same junction marked in red for protect and reference (needed with step driver)................


regards
sekhar

 

[kASD]

Stringent SOA needs in Class-AB are met with relaxed ones in Class-H.

For example, 1kW @ 2Ohms in Class-AB using 5200/1943 requires atleast 9-10Pairs with rails around +/-90V whereas only 5Pairs will do the job in Class-H if rails are split in say +/-55 & +/-95.

In a Class- AB reactive loading we have high dissipation because output device has considerable VCE + Ic across it hence heating very much, Whereas in Class-H, this VCE is quite less across the device for same output load, hence less heat and more headroom.

 

[sekhar]

so workhorse how much power do u think 12pairs of 2sc5200/1943 with rail voltage of +-140 and a 2 step driver will produce safetly


regards
sekhar