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Old 13th August 2010, 11:21 AM   #131
comasus is offline comasus  India
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i am confusing between these two schematics which one is correct?

what is Iq of this amp?
what is offset at output?
what is the wattage of the remaining resistors?
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File Type: jpg Apex 550W classB sch.jpg (192.2 KB, 1380 views)
File Type: jpg Apex 50-500W classB0.jpg (196.4 KB, 1315 views)
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Old 13th August 2010, 01:13 PM   #132
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Quote:
Originally Posted by comasus View Post
i am confusing between these two schematics which one is correct?

what is Iq of this amp?
what is offset at output?
what is the wattage of the remaining resistors?
Both schematics are correct, only difference is connection of PNP driver emiter, on second schematics connection is same as PCB circuit.
Iq is 20mA, and this is VAS Iq, output stage work in class B
Offset at the output is +/-10mV (+/-20mVmax) without matching diff pair.
Resistors wattage is 0,25W if no other notification.
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Old 13th August 2010, 01:31 PM   #133
comasus is offline comasus  India
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What is the range of frequency of this amplifier?
can you give me (schematic) pre-amplifier having two mic inputs and two AUX inputs

while using one pair of 2n3773 at voltage of +/-48 what is the power of this amp

can i use 16ohms 100watt speaker
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Old 13th August 2010, 04:59 PM   #134
comasus is offline comasus  India
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what is the Iq of this amp when i use only one pair of 2n3773
What is the range of frequency of this amplifier?
can you give me (schematic) pre-amplifier having two mic inputs and two AUX inputs

while using one pair of 2n3773 at voltage of +/-48 what is the power of this amp

can i use 16ohms 100watt speaker
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Old 13th August 2010, 05:24 PM   #135
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Quote:
Originally Posted by comasus View Post
what is the Iq of this amp when i use only one pair of 2n3773
What is the range of frequency of this amplifier?
can you give me (schematic) pre-amplifier having two mic inputs and two AUX inputs

while using one pair of 2n3773 at voltage of +/-48 what is the power of this amp

can i use 16ohms 100watt speaker
This amp is perfect for you, build it and come with questions leter.
Preamp is in thread:
http://www.diyaudio.com/forums/solid...q-preamps.html
use two of them and mix with resistors before master volume pot.
Regards
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Old 14th August 2010, 09:28 AM   #136
comasus is offline comasus  India
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I heard that class B is worst amplifier for audio applications because they produce distortion at low and high volumes

but you are telling me that it is perfect for me

I don't know whether this amplifier performs well

If you surely tell that this will give perfect sound and quality i will proceed to start doing this amp

otherwise if you have another amplifier like class D or H please send

Last edited by comasus; 14th August 2010 at 09:32 AM.
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Old 14th August 2010, 10:13 AM   #137
AndrewT is online now AndrewT  Scotland
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ClassB biasing for the output stage saves heat and causes crossover distortion.
The distortion sounds worse at higher frequencies. It also becomes a higher proportion of the signal when the signal is quiet.

A full range amplifier biased to ClassB will, generally, not sound as nice as a ClassAB biased amplifier.

A bass only amplifier biased to ClassB may not sound any different to a ClassAB biased amplifier because the mid and treble signals are not being amplified and because the bass is not heard if it is only playing quietly (Fletcher & Munsen & others).
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regards Andrew T.
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Old 14th August 2010, 11:16 AM   #138
wahab is offline wahab  Algeria
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This amp has awfull THD ratios, not only because it s
working in Class B, but also because of an huge overcompensation.
No way it can be branded hifi, not even as a bass box amplifier....

In a way, it can only disappoint even the most enthusiast beginner..
A sad gift to give them such a misdesign...
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Old 14th August 2010, 01:41 PM   #139
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Quote:
Originally Posted by wahab View Post
This amp has awfull THD ratios, not only because it s
working in Class B, but also because of an huge overcompensation.
No way it can be branded hifi, not even as a bass box amplifier....

In a way, it can only disappoint even the most enthusiast beginner..
A sad gift to give them such a misdesign...
Beginners will be hapy with this amp, work at first swich every time, powerfull, great stability, no adjust, available parts... and THD ratio is inaudable anyway.
Regards
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Old 14th August 2010, 05:23 PM   #140
comasus is offline comasus  India
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what is the replacement of these transistors MJE15030/31 because these are not available in my area
please tell me as early as possible
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