Hello I would like help, first I want to say that I am not a professional electronics, just hobby. I want to mount the almost complementary amplifier of 500w. I set up the circuit in Multisim 14, but I don't know why the power of the power is approximately 32,504 mW, another question is with respect to the 12v zener diode, in this diode, the harmonic distortion was high, replaced by a 24v zener and Distortion lowered as this photo, is there any risk of replacing with a 24v diode? Thanks in advance.
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Your 'scope shows 500mV Peak OUTput.
Which is indeed 30-some milliWatts.
However it looks like the INput is also 500mV. And the amplifier voltage gain should be way over 10, apparently 69. What happened to your voltage gain??
IAC, you can NOT get 500 Watts of audio power from just four power transistors. Probably in simulation, *maybe* on test-bench with resistor load, but real speakers will pop it FAST. (The first Phase Linear claimed 200W from four devices and was not real robust in hard work.)
Which is indeed 30-some milliWatts.
However it looks like the INput is also 500mV. And the amplifier voltage gain should be way over 10, apparently 69. What happened to your voltage gain??
IAC, you can NOT get 500 Watts of audio power from just four power transistors. Probably in simulation, *maybe* on test-bench with resistor load, but real speakers will pop it FAST. (The first Phase Linear claimed 200W from four devices and was not real robust in hard work.)
If you want to use a 24V zener diode, increase R4 (your R12) to 30k, otherwise you'll be doubling input stage current and won't know whether your improvement isn't actually a result of that.
Your 32.5 W of output is a result of input level + amplifier voltage gain (= 1 + R29/R28) + load impedance. It is not a match for the 1 Vpp input level that you should be getting but rather close to half that - is XFG1 hooked up correctly?
Output inductor L1 || 10 ohms is not optional.
500 W of output seems rather optimistic for this circuit, I imagine it would be closer to 200 W / 4 ohms.
BTW, mind using an image editor that does not include all this silly white space around your screenshots? Maybe XnView or something. Even the trusty Snipping Tool is smarter than that.
Your 32.5 W of output is a result of input level + amplifier voltage gain (= 1 + R29/R28) + load impedance. It is not a match for the 1 Vpp input level that you should be getting but rather close to half that - is XFG1 hooked up correctly?
Output inductor L1 || 10 ohms is not optional.
500 W of output seems rather optimistic for this circuit, I imagine it would be closer to 200 W / 4 ohms.
BTW, mind using an image editor that does not include all this silly white space around your screenshots? Maybe XnView or something. Even the trusty Snipping Tool is smarter than that.
To my surprise, I seem to be able to drive to the rails at full range audio, with +/-30V rails, an Advent Prodigy tower speaker (measures 4DCR) in parallel with a 4R 8" sub, and the rear surround speakers, with just one pair of TO-220 cheap stripe FETs in my hybrid stereo.
After a bit, they do get hot to the touch but seem to plug along.😎 It is too loud for the living room, walls and floor vibrating, but it go will there....shoot the moon!
Of course with BJT, secondary breakdown is really what limits reactive output power.
After a bit, they do get hot to the touch but seem to plug along.😎 It is too loud for the living room, walls and floor vibrating, but it go will there....shoot the moon!Of course with BJT, secondary breakdown is really what limits reactive output power.
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XFG1's negative output is shorted to COM, that can't be right surely?
Changing that zener changes the differential input sections standing current.
Changing that zener changes the differential input sections standing current.
Hi clpk
I have several comments about your basic design that you need to review. Your design should not fail premature. I designed Audio Amplifiers for several company’s Acoustic Control, BGW, JBL and others.
1. Add input R to keep C1 from DC shift. 100k to ground.
2. Small R to the base of Q1. RF Oscillator?
3. Add small R to each Emitter of Q1 & Q4. Control gain bandwidth of the first stage.
4. Replace D3 & D4 with active Vbe stage. Active control of bias current.
5. Add small R or diode to Q6 emitter. Stop saturation storage of output stage.
6. Add RC across R29. Control gain bandwidth of overall amplifier, Pole Zero.
7. Add 2 more outputs stages to meet 500 watts and 60 degree loads, Do a real SOA load line plot.
Good luck. Duke
I have several comments about your basic design that you need to review. Your design should not fail premature. I designed Audio Amplifiers for several company’s Acoustic Control, BGW, JBL and others.
1. Add input R to keep C1 from DC shift. 100k to ground.
2. Small R to the base of Q1. RF Oscillator?
3. Add small R to each Emitter of Q1 & Q4. Control gain bandwidth of the first stage.
4. Replace D3 & D4 with active Vbe stage. Active control of bias current.
5. Add small R or diode to Q6 emitter. Stop saturation storage of output stage.
6. Add RC across R29. Control gain bandwidth of overall amplifier, Pole Zero.
7. Add 2 more outputs stages to meet 500 watts and 60 degree loads, Do a real SOA load line plot.
Good luck. Duke
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