500W PA amplifier with Limiter

[kamranyousaf]

any one can check this if ok

Dear ,

What is GERIBESLIMI and 16V ?

 

[AndrewT]

output power is a function of supply voltage. ...............

for example if you use dual 50vdc for supply on 4ohm speaker you'll have

Wrms = ((50x2) : 2.82)^2 : 4 = 35.46^2 : 4 = 314 Wrms

Balderdash !

+-50Vdc from the PSU is likely to result in 200W to 230W into 4r0 test load.
Built badly the maximum power could be as low as 120 to 150W into 4r0.

 

[hyperblaster89]

there isn't any needs to say that's a balderdash. i was referring to an article on "Nuova Elettronica". attached is the article's picture. now i don't wanna make a lot for noise talking and talking about watts, if i was wrong please explain why and which is the correct formula (obviously the efficiency isn't 100%)

 

[apexaudio]

output power is a function of supply voltage. the exact function is:

Wrms = (0.8xVcc : 2.82)^2 : load

for example if you use dual 50vdc for supply on 4ohm speaker you'll have

Wrms = (0.8x(50x2) : 2.82)^2 : 4 = 28.3^2 : 4 = 200 Wrms

 

[hyperblaster89]

thanks apex for quick reply!

 

[TonyTecson]

AndrewT is right about psu quality........

my shortcut for estimating power, {[(Vcc-Vee)/3]^2}/Rl

but of course without actually seeing how big or how heavy your power traffo is, all computations tend to be just that, computations....

 

[hyperblaster89]

so doesn't exist a unique formula?

however design quality is the most important number in equations and watts doesn't stay for more loud. building speakers a big part of work is done if the enclosure is well-projected!

good night diyaudio!

 

[TonyTecson]

mere variations on the same theme....they arrive at more or less the same figures....

i stopped counting the watts a long time ago.....now my priority is sound quality.....and power in watts is never an indicator of sound quality.....

 

[kamranyousaf]

output power is a function of supply voltage. the exact function is:

Wrms = (0.8xVcc : 2.82)^2 : load

for example if you use dual 50vdc for supply on 4ohm speaker you'll have

Wrms = (0.8x(50x2) : 2.82)^2 : 4 = 28.3^2 : 4 = 200 Wrms

Sir,

Would u please explain the parameters of this formula Thanks.

 

[apexaudio]

Sir,

Would u please explain the parameters of this formula Thanks.

With unregulated PSU on class AB amp out will be about 80% of Vcc.

 

[WSDS]

X-sistor Replacement

Sir what transistor did u use to replace the MJE 15032, 15033 and 340, it seems it is not available even in Raon.

Thanks.

nope...got them replaced...as what sir apex advised,...nsl 32 can be replaced with regular LED and LDR,...47k resistor may also do the job in place of LDR...LED serves as clip indicator...i placed it in front of the amp so i can see if amp clips...then i may lower down the volume...

you can also place LED and LDR in a black tube facing each other...
this serves as an improvised NSL32...
tnx to sir apex advices...everything worked fine...

 

[comasus]

Mile please help me to increase the treble in this amplifier i adjusted bias to 25mA as you suggested but no increase in treble please help me

 

[TonyTecson]

Sir what transistor did u use to replace the MJE 15032, 15033 and 340, it seems it is not available even in Raon.

Thanks.

hi, how many do you need? i am also from Pasig, call me 628-2996.....

 

[comasus]

Hi! Mile

Recently i noticed that the speaker(magnet) used with B500 amp is getting heated up more (can't touch for more than 3 seconds)even at medium volume,
there is no that much heat producing when used with other amp (100watt)

there is no dc offset to this amp but i am scared why this is happening

my speaker max power 150watt RMS 8R
amp output voltage is 28volts RMS (while testing)

Is this normal?? or anything problem with the amp???

 

[apexaudio]

Hi! Mile

Recently i noticed that the speaker(magnet) used with B500 amp is getting heated up more (can't touch for more than 3 seconds)even at medium volume,
there is no that much heat producing when used with other amp (100watt)

there is no dc offset to this amp but i am scared why this is happening

my speaker max power 150watt RMS 8R
amp output voltage is 28volts RMS (while testing)

Is this normal?? or anything problem with the amp???

You have HF instability, check with scope...

 

[comasus]

You have HF instability, check with scope...

Hi! Mile
I don't have scope
How can i remove that HF instability

Thank you for your reply

 

[comasus]

How can i avoid HF instability

 

[kamranyousaf]

Sir what transistor did u use to replace the MJE 15032, 15033 and 340, it seems it is not available even in Raon.

Thanks.

Sir,

I think u can use Tip41c & Tip42c and D669 & B649 Max for +-75volts Thanks.

Regards
Kamran.

 

[comasus]

You have HF instability, check with scope...

Hi! Mile

How can i solve this problem please help me

 

[pankaj kashyap]

Dear sir plz tell me what is the point A or B in APEX B500 circuit.