500W PA amplifier with Limiter

[karachay]

i fix problem my friends all my problems coming from ne5532. i buy 10 of them but i think they are fake or bad. only 1 channel work cause only 1 opamp was good.

so i change it with tl072 and all problems finish

thank you for all helping for fix problems and thank you soo much to Mile for share this sweet amp.

 

[randyboy]

My b500 works fine,clear sounds and powerful,but 4.7k 2watts resistor (R13 & R14) are hot,can't touch with my bare hand, is it normal or not?

 

[randyboy]

my power supply is +-75v

 

[apexaudio]

My b500 works fine,clear sounds and powerful,but 4.7k 2watts resistor (R13 & R14) are hot,can't touch with my bare hand, is it normal or not?

Yes it is normal.

 

[apexaudio]

My b500 works fine,clear sounds and powerful,but 4.7k 2watts resistor (R13 & R14) are hot,can't touch with my bare hand, is it normal or not?

Yes it is normal.

 

[randyboy]

Yes it is normal.

Is it okay if I replace 2watts resistor by 5watts?

 

[apexaudio]

Is it okay if I replace 2watts resistor by 5watts?

It is ok.

 

[randyboy]

I want to upgrade my b500 into class h using step driver Apex sd-5,can u help me how to connect the the sd-5 to b500

 

[apexaudio]

I want to upgrade my b500 into class h using step driver Apex sd-5,can u help me how to connect the the sd-5 to b500

 

[randyboy]

Thank you very much

 

[randyboy]

Mur1620 and irf540 need to attach on heat sink?

 

[Shelah]

follow up

I just gone went through the the whole thread and got quite a interested in making this amplifier. I have an 80-0-80vac 1600va transformer and I would like to make b500 TEF or b600 TEF stereo at 4ohms for PA use. what upgrades or changes can I make on the following?

>number of pairs of outputs per channel
>r24 and r25 in the case of b500
>bias circuit (r23 r24 and q5)
>any other upgrades if any.

Thanks and regards

Sir mile, any advice please?

 

[naf]

Sir mile, any advice please?

80vac-0-80vac to high for class AB

 

[stewin]

Hi all . I wanted to use this amp with 5pairs transistors to power my 2ohm subwoofer :-

so my question is what Is the safe voltage to use
with a 2ohm load for extended periods of time??

what other modifications do I need to do to make it
robust at 2ohms operation??

 

[arksystem]

Hi sir apex
I'm montajhe b500
Mje15032/3 replace tip41/2c
Tip 41/2c and c5200/a1943 hooootttt.
Way??!!!!!!!
Please help

 

[karachay]

Hi sir apex
I'm montajhe b500
Mje15032/3 replace tip41/2c
Tip 41/2c and c5200/a1943 hooootttt.
Way??!!!!!!!
Please help

they need cooler did you do that? i have too much problems with this amp but all problems coming from bad or fake parts. and some from bad soldering. bold your lines from c5200 and a1943 check some pictures last pages.

amp is fine just need to focus on it when you making soldering cause its thin lines.

 

[arksystem]

they need cooler did you do that? i have too much problems with this amp but all problems coming from bad or fake parts. and some from bad soldering. bold your lines from c5200 and a1943 check some pictures last pages.

amp is fine just need to focus on it when you making soldering cause its thin lines.

Hi sir
Tanks help
Ok amplifier b500
You instal nsl32 amp?!
I'm uninstall nsl 32.
-5db exit amp 2R distort.
60/0/60 dc voltajhe
2R =????watt

 

[sandman15th]

I just finish my second pair b500 tef pcb layout by Mr. liempoo and Mr. miles thanks you.

never mind the wirings for testing only =) please click the link on youtube to view



YouTube

 

[stewin]

Hi all . I wanted to use this amp with 5pairs transistors to power my 2ohm subwoofer :-

so my question is what Is the safe voltage to use
with a 2ohm load for extended periods of time??

what other modifications do I need to do to make it
robust at 2ohms operation??

also just wondering is apex ax14 with multiple pairs better than apex 500watts pa , in terms of stability and durability?

 

[karachay]

Hi sir
Tanks help
Ok amplifier b500
You instal nsl32 amp?!
I'm uninstall nsl 32.
-5db exit amp 2R distort.
60/0/60 dc voltajhe
2R =????watt

yes but i use handmade nsl-32 YouTube

which resistor is 2ohm? if you mean R2 on schematic its 1/4w