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Old 30th May 2010, 05:15 PM   #11
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Originally Posted by jaycee View Post
I have to honestly say that I dont think "beginners" should be building powerful amps. I also don't see why theres no adjust - a resistor, a trim pot and a transistor dont exactly add a lot of complexity to the circuit.
Beginners who want to build powerful amp for party... can start with this amplifier with single pair and add more outputs later, and they don't want adjust bias, just connect power supply and play.
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Old 30th May 2010, 06:01 PM   #12
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MJE340, MJE350, MJE15030 and MJ15031 must have TO220 heatsinks.
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Old 30th May 2010, 06:47 PM   #13
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Beginners who want an amp for a party are normally trying to do it cheaper than buying one - which they won't manage. With a total of 130V DC present, they can do a lot of damage.
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Old 30th May 2010, 07:01 PM   #14
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Thank you mr. apex for the circuit and P.C.B. design , as i have a good stock of 2n37773 transistors with me.I am a professional Audio and stage light hirer and I am using 2n3773 Amplifiers made as per the 325 watts circuit published in electronics Australia long time ago with modification of using 10 pairs per channel and 70-0-70 volt dc. Will you be kind enough to send this ciruits slew rate and distortion levels . please send any modification also if there is any.as i plan to modify my 10 stereo amplifiers which are made as per cosmic amplifier Circuits with 4pairs 2n3055 each channel. I personally rely much on metal casing transistors. with lots of regard vedmitra Sharma from city of Tajmahal.
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Old 30th May 2010, 07:03 PM   #15
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Some baxendall diode wouldn't cost much.
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Old 30th May 2010, 08:43 PM   #16
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Originally Posted by jaycee View Post
Beginners who want an amp for a party are normally trying to do it cheaper than buying one - which they won't manage. With a total of 130V DC present, they can do a lot of damage.
With suggested PSU and protect circuit or triac DC protection, and fuses on amp pcb, they can't do any damage.
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Old 30th May 2010, 08:58 PM   #17
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Originally Posted by vedmitraa View Post
Thank you mr. apex for the circuit and P.C.B. design , as i have a good stock of 2n37773 transistors with me.I am a professional Audio and stage light hirer and I am using 2n3773 Amplifiers made as per the 325 watts circuit published in electronics Australia long time ago with modification of using 10 pairs per channel and 70-0-70 volt dc. Will you be kind enough to send this ciruits slew rate and distortion levels . please send any modification also if there is any.as i plan to modify my 10 stereo amplifiers which are made as per cosmic amplifier Circuits with 4pairs 2n3055 each channel. I personally rely much on metal casing transistors. with lots of regard vedmitra Sharma from city of Tajmahal.
I have not slew rate and distortion levels, I use this Dynacord clone long time ago, and there's no any modification for this circuit, but this simple circuit give you great chance to build or fast repare any old amp. This is retro design.
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Old 30th May 2010, 10:35 PM   #18
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Originally Posted by bobodioulasso View Post
Some baxendall diode wouldn't cost much.
1N4148 can stabilised bias if are montage on heatsink, and connect with trimpot in series for adjust bias.
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Old 30th May 2010, 10:57 PM   #19
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I meant a diode in the 15031 emmitor to compensate dissymetry.
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Old 30th May 2010, 11:09 PM   #20
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I meant a diode in the 15031 emmitor to compensate dissymetry.
That will increase crosover distortion
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