simple ne5532 and irf630

[LoveVirus]

I construction a simple amplifier,none capacitor,feel sound well,someone give me some advice,my english very poor,hope everyone understand,~~haha~~
in fact,i use irf630 instead of irf610
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[lineup]

Hello.
I use MultiSim, too.
I tested your circuit. It works well.

What I should change.
1. I should use +-18V Supply

2. Use NE5534P. Is a better opamp than NE5532
And you can build two channels separate. Dual Mono blocks.

3. IRF630 is better. 74 Watt. IRF610 only 36 Watt.
Myself, I should go for IRF540N/IRF9540N. More than 100 Watt


Here is my variant. No longer as simple as your. But it is not very difficult.

It gives max 14 Watt RMS into 8 Ohm
By using 2 BOOTSTRAP capacitors we help opamp to give higher volt out.
One thing to fix is the DC offset: -115 mV
This can be done using Pin1 and Pin5 of NE5534

[lineup]

Sorry.
To fix DC Offset we use Pin1 and Pin8 of NE5534.

[LoveVirus]

First thanks your advice,In reality,some little diffefrence to above,in output I add 2 capacitor(1000uf+1000uf) of one channel,protected my speaker,extra advantage is reduce current, i guess bass may be affect

[LoveVirus]

I see your circuit,don't understand your 220Ohm,drop it may be better,add to opamp drive current

[LoveVirus]

By my test,I feel two mosfet little diffrence submerged in feedback,someone agree with me?

[RLa]

You have to add bias management circuit for the output stage otherwise the circuit will end up in thermal runaway.

[lineup]

Originally Posted by LoveVirus

I see your circuit,don't understand your 220Ohm,drop it may be better,add to opamp drive current

Gate-stopper values ?

220 Ohm at GATE of MOSFET is to prevent oscillation.
They are used very often and we call these resistors Gate Stoppers
You can find them resistors in almost every MOSFET amplifier.

[Sebastiaan]

Originally Posted by LoveVirus

I construction a simple amplifier,none capacitor,feel sound well,someone give me some advice,my english very poor,hope everyone understand,~~haha~~
in fact,i use irf630 instead of irf610
Attachment 185012

Dear LoveVirus,

Why not use the NE5534 instead and drive the output stage from pin 5? Basicly you drive them direct from the NE5534 VAS which will be in class A.

With kind regards,
Bas

[Sebastiaan]

Originally Posted by lineup

It gives max 14 Watt RMS into 8 Ohm
By using 2 BOOTSTRAP capacitors we help opamp to give higher volt out.
One thing to fix is the DC offset: -115 mV
This can be done using Pin1 and Pin5 of NE5534

Dear Lineup,

Doesn't that increase the distortion of the NE5534? I remember some older measurement I made that distortion rise if you go above approx. 50mV, by miss balance the input transistors in the NE5534

With kind regards,
Bas