No doubt.
You should edit that to:
Don't worry, we have a lot of excitement around here , about a 1000W amp which was posted *almost* as a joke, considering that same amp designer has also posted *impressive*, World class amps here, but none of them created such a sensation.
I guess "1000W" is the magic label 😛
There are different tradition in the country, single pair tip3055/2955 is 100watt, single pair 2n3055/mj2955 is 150W single pair sanken MT200 is 200W, then 4pair that MJL should be 4x150W or 600W.
Also that TIP won't work at high voltages. I found this sch
http://s19.postimg.org/jk0y7uf5f/Namec_sch.png
45 Volts AC RMS gives 63.64 Volts Peak.
Subtract 3 Volts for worst-case rectifier drop. Gives 60.64 Volts peak.
Assume 6 Volts (just a guess) for minimum voltage between power rail and output, Vclip, across amplifier.
So peak rail voltage, Vrailpk, is assumed to be 60.64 Volts.
You cannot get 1000 Watts RMS into 2 Ohms or more, with that rail voltage.
But you could get 1000 Watts RMS into 1 Ohm:
Voutpk = √(2(P_rms)(Rload))
For 1000 W RMS into 1 Ohm:
Voutpk = √(2(1000)(1)) = 44.72 Volts Peak
Vout_RMS = 31.62 Volts
The minimum reservoir capacitance would be:
Cmin (in uF) = 1000000(Vpk/(Rload(Vrail-Vclip-Vpk)))( (1/(2 fmains)) + (0.02/Voltage_Rating) )
Cmin (in uF) = 1000000(44.72/(1(60.64-6-44.72)))( (1/(2x50)) + (0.02/63) )
Cmin = 46520 uF
I would recommend using qty 10 x 4700 uF, at a minimum.
If you used 100000 uF, then the max rated RMS output power would be 1226 Watts, because the max clipping voltage would be lower, so the rated max peak output voltage could be higher.
-------------------
For higher-impedance speakers:
Voutpk = √(2(P_rms)(Rload))
Voutpk for 1000W RMS into 8 Ohms would be 126.4 V peak. You would have to add Vripple, Vclip, and Vdiodes to that, to get the needed transformer output voltage. The peak current would be 15.8 amps. So maybe add 15 Volts, giving 141 V pk, or 100 V RMS transformer output. The good news is that it would only need about 22000 uF per rail.
Voutpk for 1000W RMS into 4 Ohms would be 89.4 V peak. You would have to add Vripple, Vclip, and Vdiodes to that, to get the needed transformer output voltage. The peak output current would be 22.4 amps. So maybe add 15 Volts, giving 104.4 V pk, or 74 V RMS transformer output. The good news is that it would only need about 25200 uF per rail (but 47000 uF would get the ripple down to 5%).
Many amp. kits from Indonesia claimed more power than it's should be. They can not distinguish about RMS power and PMPO power or they did not care. I doubt they even measure their designs. It is shame 
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1000 WATT PEAK or 1000 WATT RMS 😕 ? I don't think it would be able to result 1000 WATT RMS unless --> the loudspeaker is "1-ohms 😱 " with at about 31.5V RMS output (if DC supply at about 63V DC).
(BTW, it so overkill to parallel 8-speakers to get 1-Ohms impedance
)
(BTW, it so overkill to parallel 8-speakers to get 1-Ohms impedance
)
I think we all realise that ratings like this for simple, low voltage designs are either using technical tricks like PMPO estimations (they won't be measured results anyway) or specifying the device for operating conditions that would destroy it instantly.
Either way here though, whether it is normal commercial practice in Indonesia or not, it's just lies and deception.
Either way here though, whether it is normal commercial practice in Indonesia or not, it's just lies and deception.
I heard the rumor which mentions that the *n* group/forum on Facebook even disallow the discussion of electronic theorems and will kick out a member who talking about formula or electronic theorems on the group wall.
Yes it is normal. Anyway they like the amp not because it is 1000W. This amp is similar to the other old and famous 68watter (1000W is too far away). Very simple but the sound is decent.
That so tragic, if that is really a "normal" commercial practice in Indonesia. I don't think that all "normal" peoples at Indonesia will agree.
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When you see "10kW Car Hi Fi sound system", like you can see promoted in many Asian and Middle Eastern countries, I think you know this is not just Indonesian marketing. This is systematic exaggeration of product claims to get more sales. If the countries have no legal protection for consumers, and many countries don't, or don't uphold their own laws, sellers just get as ruthless and exaggerate as much as they need to sell more products. 'Too bad if your amplifier only produces 500W total RMS or as much as your car generator can supply it.
How many would think to test or pay to have someone test their amplifier for power output? Most guys will be happy if speakers make the doors flex at about 20W bass. It's probably good to have no idea about real power levels and what they mean, as long as the money you pay is not greater than the appropriate selling price for what you really get. As Onto said (I think), 1000W is too far away - perhaps meaning that no one will seriously expect that level of performance or such a power is inconceivable.
How many would think to test or pay to have someone test their amplifier for power output? Most guys will be happy if speakers make the doors flex at about 20W bass. It's probably good to have no idea about real power levels and what they mean, as long as the money you pay is not greater than the appropriate selling price for what you really get. As Onto said (I think), 1000W is too far away - perhaps meaning that no one will seriously expect that level of performance or such a power is inconceivable.
I found that VAS current mirror will result impedance at about 19.5 kilo Ohms ~ 20 kilo Ohms. Implement TIP41/TIP42 is so overkill for VAS & current source of VAS with such kilo-ohms impedance.
Now you raise the big questions like "how much audio power can I get using obsolescent, low voltage, industrial power transistors?" This design is audio at its worst, where parts are selected from just a few widely available but most important - very cheap industrial transistors.
TIP 41 has 100V Vceo(max) but BD139 only 80V, so what happens ? The designer selects the crap power transistor for the VAS because it has higher rating, but that says nothing about linearity as you exceed the basic TIP 41 40V SOA. This is not good thinking - it might be better as a motor drive rather than audio amplifier, even if it does work.
40 years ago, I guess it might have been worth using in poor areas but it won't hold together approaching its ratings without extensive protection circuitry or a lot of repairs - a disaster in the making and unless you like PA with a "certain" sound quality, the public will be far from impressed.
TIP 41 has 100V Vceo(max) but BD139 only 80V, so what happens ? The designer selects the crap power transistor for the VAS because it has higher rating, but that says nothing about linearity as you exceed the basic TIP 41 40V SOA. This is not good thinking - it might be better as a motor drive rather than audio amplifier, even if it does work.
40 years ago, I guess it might have been worth using in poor areas but it won't hold together approaching its ratings without extensive protection circuitry or a lot of repairs - a disaster in the making and unless you like PA with a "certain" sound quality, the public will be far from impressed.
Yeah, I agree with you Ian 😉 ...
(And I hope that we will not find any other jokes as we may find yet another "special" power amp schematic that even with VAS implemented MJ15004 😀)
(And I hope that we will not find any other jokes as we may find yet another "special" power amp schematic that even with VAS implemented MJ15004 😀)
Ah. You may not know what noob trying to modify. They don't know much about electronic knowledge, but ears and luck sometimes comes together.
From the name (namec) and 1000W, seems that the owner like it so much.😀 (as I know, it is not a comercial amp)
It is not best, but simple with decent sound.
From the name (namec) and 1000W, seems that the owner like it so much.😀 (as I know, it is not a comercial amp)
It is not best, but simple with decent sound.
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