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<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
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<html lang="en">
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<head>
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<meta http-equiv=Content-Type content="text/html; charset=windows-1252">
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<title>The Class-A Amplifier Site - Transistor Substitutes</title>
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<link rel="StyleSheet" href="class-a.css" type="text/css" media="screen, print">
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<link rel="shortcut icon" type="image/ico" href="favicon.ico">
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</head>
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<body background="slate.jpg" bgcolor="#E8E8E8" lang=EN-GB link=blue vlink=blue>
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<div class=Section1>
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<p align=right style='text-align:right'><b>The Class-A Amplifier Site</b></p>
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<p align=right style='text-align:right'><span style='font-size:10.0pt'>This
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page was last updated on 7 November 2001</span></p>
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<p><b><span style='color:blue'><a href="index-1.htm" title=index-1.htm>[ Back
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to Index ]</a></span></b></p>
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<p> </p>
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<p align=center style='text-align:center'><b><span style='font-size:20.0pt'>Transistor
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Substitutes</span></b></p>
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<p> </p>
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<p> </p>
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<p>The semiconductors used in the original 1969 circuit are, naturally, no longer
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available and even some of those shown in the 1996 update article can be
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difficult to source in some localities. The following list of substitutes has
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been prepared to assist those who are having difficulties in finding the
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specified devices. I have also included details of the working voltage, current
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and power dissipation for each transistor, when used in the 1996 circuit, so
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that other alternative devices may be considered. </p>
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<p> </p>
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<div align=center>
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<table class=MsoNormalTable border=1 cellspacing=0 cellpadding=0
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style='border-collapse:collapse;border:none'>
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<tr style='height:19.85pt'>
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<td width=121 style='width:72.45pt;border:solid windowtext 1.0pt;padding:
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0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Device</p>
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</td>
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<td width=232 style='width:139.2pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Original Device 1969</p>
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</td>
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<td width=232 style='width:139.2pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Original Device 1996</p>
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</td>
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<td width=242 style='width:145.2pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Substitutes</p>
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</td>
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</tr>
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<tr style='height:19.85pt'>
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<td width=121 style='width:72.45pt;border-top:none;border-left:solid windowtext 1.0pt;
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border-bottom:none;border-right:solid windowtext 1.0pt;padding:0cm 0cm 0cm 0cm;
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height:19.85pt'>
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<p align=center style='text-align:center'>Tr1 / Tr2</p>
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</td>
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<td width=232 style='width:139.2pt;border:none;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>MJ480 / MJ481</p>
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</td>
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<td width=232 style='width:139.2pt;border:none;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>2N3055</p>
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</td>
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<td width=242 style='width:145.2pt;border:none;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>2N3055<EFBFBD> / 2 x TIP3055</p>
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</td>
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</tr>
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<tr style='height:19.85pt'>
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<td width=121 style='width:72.45pt;border:solid windowtext 1.0pt;padding:
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0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Tr3</p>
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</td>
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<td width=232 style='width:139.2pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>2N697 / 2N1613</p>
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</td>
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<td width=232 style='width:139.2pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>2N1711</p>
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</td>
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<td width=242 style='width:145.2pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>2N3019 / BD139</p>
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</td>
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</tr>
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<tr style='height:19.85pt'>
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<td width=121 style='width:72.45pt;border:solid windowtext 1.0pt;border-top:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Tr4</p>
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</td>
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<td width=232 style='width:139.2pt;border-top:none;border-left:none;
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border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>2N3906</p>
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</td>
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<td width=232 style='width:139.2pt;border-top:none;border-left:none;
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border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>BC212</p>
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</td>
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<td width=242 style='width:145.2pt;border-top:none;border-left:none;
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border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>BC559 / BC560</p>
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</td>
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</tr>
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<tr style='height:19.85pt'>
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<td width=121 style='width:72.45pt;border:solid windowtext 1.0pt;border-top:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Tr5</p>
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</td>
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<td width=232 style='width:139.2pt;border-top:none;border-left:none;
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border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>None</p>
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</td>
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<td width=232 style='width:139.2pt;border-top:none;border-left:none;
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border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>MJE371</p>
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</td>
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<td width=242 style='width:145.2pt;border-top:none;border-left:none;
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border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
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padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>BD140</p>
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</td>
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</tr>
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</table>
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</div>
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<p><span style='font-size:6.0pt'> </span></p>
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<p align=center style='text-align:center'>Table 1. Commonly available or
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preferred transistor substitutes.</p>
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<p> </p>
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<p align=left style='margin-top:0cm;margin-right:34.0pt;margin-bottom:0cm;
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margin-left:34.0pt;margin-bottom:.0001pt;text-align:left'>Notes to Table 1:</p>
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<p align=left style='margin-top:0cm;margin-right:34.0pt;margin-bottom:0cm;
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margin-left:34.0pt;margin-bottom:.0001pt;text-align:left'>The 2N3055 should be
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epitaxial-base type with high f<span style='font-size:8.0pt'>T</span>
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(preferably 4 MHz) </p>
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<p align=left style='margin-top:0cm;margin-right:34.0pt;margin-bottom:0cm;
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margin-left:34.0pt;margin-bottom:.0001pt;text-align:left'>The 2 x TIP3055 are a
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parallel pair with 0R1 emitter resistors</p>
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<p align=left style='margin-top:0cm;margin-right:34.0pt;margin-bottom:0cm;
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margin-left:34.0pt;margin-bottom:.0001pt;text-align:left'>The BD139 should
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preferably be selected for high gain to minimise distortion. If possible, use
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the BD139-16 (the manufacturer<65>s higher gain device)</p>
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<p> </p>
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<p> </p>
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<p>The use of more modern <20>audio<69> power transistors with a high current
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gain-bandwidth product (f<span style='font-size:8.0pt'>T</span>), such as the
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2SC5200, 2SC3281 and MJL3281A, is not recommended at present. The >30MHz f<span
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style='font-size:8.0pt'>T</span> of these devices causes the open-loop gain to
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remain above unity when the phase shift through the amp reaches 180<38>. This
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results in instability and oscillation, which requires additional compensation
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such as a dominant pole capacitor. In a simple circuit such as this, the provision
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of a compensation capacitor can significantly increase distortion levels unless
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other circuit changes are made (which perhaps defeats the object of this simple
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design). However, I will be investigating various possible options for solving
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the instability problems since I would really like to try the highly linear
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MJL3281A device.</p>
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<p> </p>
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<p>I have received feedback from one constructor, Tim Andrew, who has been
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trying alternative output transistors in his JLH 1996 version. The MJL3281A
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gave clearly audible oscillation. The MJ21194 gave a noticeable improvement in
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sound quality, but introduced a low frequency hum, the cause of which has yet
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to be determined. The MJ15003 gave a significant improvement in sound quality,
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similar to the MJ21194 but without the side effects. Tim<69>s opinion is that,
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when compared to the 2N3055, the bass is tauter and faster and the top end less
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<EFBFBD>splashy<EFBFBD>. In a subsequent email about the MJ15003, Tim went on to say:</p>
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<p> </p>
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<p align=left style='margin-top:0cm;margin-right:22.7pt;margin-bottom:0cm;
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margin-left:42.55pt;margin-bottom:.0001pt;text-align:left'><em><span
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style='font-size:11.0pt;font-family:Arial;color:black;font-style:normal'><EFBFBD>It's
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no good, I just had to email you again to say how good these transistors
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are. Recordings that were previously hard and bright are now sumptuous
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with crystal clarity, while recordings that were dull are now alive with a
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new sense of vibrancy. They seem to go particularly well with the tantalum
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film resistors that I have just fitted. I know you plan at some point to
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change to full range speakers, but I would seriously recommend that
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instead, you try these transistors with paper-in-oil caps, preferably
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copper foil on the input. Audio Note are introducing large value 50 volt
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P-in-Os for speaker crossovers. If you try these too, I would say you
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would be very happy indeed. It seems people just don't realise what they
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are missing with these P-in-Os. They have a total lack of hardness that
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has to be heard to be believed. My tweeters are metal domes, people
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say they don't like them because they sound metallic, but here they have a
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smoothness and clarity that is difficult to describe. Anyway, thanks
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again for the suggestion of these transistors, they are a big step up from
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the 2N3055s and I wouldn't go back now.<2E></span></em></p>
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<p align=left style='margin-top:0cm;margin-right:1.0cm;margin-bottom:0cm;
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margin-left:42.55pt;margin-bottom:.0001pt;text-align:left'><span
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style='font-size:11.0pt'> </span></p>
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<p>Following Tim<69>s successful trial of the MJ15003, another constructor, Jason
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Wou, tried the substitution and sent me the following feedback:</p>
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<p> </p>
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<p align=left style='margin-top:0cm;margin-right:22.7pt;margin-bottom:0cm;
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margin-left:42.55pt;margin-bottom:.0001pt;text-align:left'><span
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style='font-size:11.0pt'><EFBFBD>I just replaced 2N3055 with MJ15003. It was direct
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swap. I didn't really have to adjust anything, it was<br>
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basically a one-to-one swap. I had lots of MJ15003 to build a Leach Amp. </span></p>
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<p align=left style='margin-top:0cm;margin-right:22.7pt;margin-bottom:0cm;
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margin-left:42.55pt;margin-bottom:.0001pt;text-align:left'><span
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style='font-size:11.0pt'><br>
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My impression is the MJ15003 is DEFINITLY better!! I was getting goosebumps. ;)
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Sounded so real. Smoother highs and midrange (I won't comment on bass since I
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use a subwoofer). It improved the already superb sounding amplifier even more!
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I guess I won't be using those transistors for the Leach Amp any more! <br>
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<br>
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The MJ15003 is more expensive than the 2N3055, but not by much. Maybe a dollar
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or two more. From now on if there's any amp project with 2N3055 in it, I will
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be using the MJ15003! </span></p>
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<p align=left style='margin-top:0cm;margin-right:22.7pt;margin-bottom:0cm;
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margin-left:42.55pt;margin-bottom:.0001pt;text-align:left'><span
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style='font-size:11.0pt'> </span></p>
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<p align=left style='margin-top:0cm;margin-right:22.7pt;margin-bottom:0cm;
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margin-left:42.55pt;margin-bottom:.0001pt;text-align:left'><span
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style='font-size:11.0pt'>How exciting. My amp is singing at this very moment,
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it sounds just so much better.<2E></span></p>
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<p> </p>
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<p>The MJ802 has also been proven to work in place of the venerable 2N3055, see
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<a href="jlhesl.htm" title="<22>A JLH Class-A for the Quad ESL57<35>"><EFBFBD>A JLH Class-A
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for the Quad ESL57<35></a></p>
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<p> </p>
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<p>If alternative power transistors are required, they should be selected to
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meet the requirements of Table 2 and should have an f<span style='font-size:
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8.0pt'>T</span> of around 4MHz. Devices with a low junction-case thermal
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resistance are preferred.</p>
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<p> </p>
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<p>I have not yet found a commonly available alternative for the 2N1711 (Tr3),
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other than the (selected) BD139. The 2N1711 and 2N3019 are preferred (if one or
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the other can be found) over the BD139, due to their higher gain. </p>
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<p> </p>
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<p>Other substitutes for Tr4 include, amongst others, the BC212L, BC556, BC557
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and 2SA872. Low noise devices such as the BC559, BC560 and 2SA872 are
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preferred.</p>
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<p> </p>
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<p>Note, the substitutes given above do not necessarily have the same case
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style or lead-out arrangement as the original devices. Manufacturer<65>s data
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sheets should be consulted to determine the relevant differences.</p>
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<p> </p>
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<p>The following table can be used to assist in the selection other suitable
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transistors. The table shows the peak values (derived from simulation) of
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voltage, current and power in each transistor for a 1996 design with +/- 22V
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supply rails and a quiescent current of 2A. The simulations were run using 4, 8
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and 16 ohm resistive loads and full-load figures were checked with source
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voltages set to give the maximum (non-clipping) output and with source
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frequencies of both 50Hz and 1kHz. The maximum figures obtained in the
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simulations are included in Table 2. Note, the maximum figures for a 1969
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design will be lower as the power output is less if the original article is
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adhered to. When selecting alternative devices, an allowance must be made to
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provide a factor of safety. I suggest as a minimum that the voltage and current
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be multiplied by a factor of 1.5 and the power by a factor of 2. </p>
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<p> </p>
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<div align=center>
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<table class=MsoNormalTable border=1 cellspacing=0 cellpadding=0
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style='border-collapse:collapse;border:none'>
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<tr style='height:19.85pt'>
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<td width=110 style='width:65.7pt;border:solid windowtext 1.0pt;padding:0cm 0cm 0cm 0cm;
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height:19.85pt'>
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<p align=center style='text-align:center'>Device</p>
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</td>
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<td width=168 style='width:100.95pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Voltage (Vce)</p>
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</td>
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<td width=143 style='width:85.95pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Current (Ic)</p>
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</td>
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<td width=183 style='width:109.95pt;border:solid windowtext 1.0pt;border-left:
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
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<p align=center style='text-align:center'>Average Power</p>
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</td>
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<td width=193 style='width:115.95pt;border:solid windowtext 1.0pt;border-left:
|
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none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
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<p align=center style='text-align:center'>Maximum Power</p>
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</td>
|
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</tr>
|
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<tr style='height:19.85pt'>
|
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<td width=110 style='width:65.7pt;border:solid windowtext 1.0pt;border-top:
|
|
|
none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>Tr1</p>
|
|
|
</td>
|
|
|
<td width=168 style='width:100.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>40V</p>
|
|
|
</td>
|
|
|
<td width=143 style='width:85.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
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|
<p align=center style='text-align:center'>3.1A</p>
|
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|
</td>
|
|
|
<td width=183 style='width:109.95pt;border-top:none;border-left:none;
|
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|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>45W</p>
|
|
|
</td>
|
|
|
<td width=193 style='width:115.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>49W</p>
|
|
|
</td>
|
|
|
</tr>
|
|
|
<tr style='height:19.85pt'>
|
|
|
<td width=110 style='width:65.7pt;border:solid windowtext 1.0pt;border-top:
|
|
|
none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>Tr2</p>
|
|
|
</td>
|
|
|
<td width=168 style='width:100.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>40V</p>
|
|
|
</td>
|
|
|
<td width=143 style='width:85.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>2.7A</p>
|
|
|
</td>
|
|
|
<td width=183 style='width:109.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>43W</p>
|
|
|
</td>
|
|
|
<td width=193 style='width:115.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>56W</p>
|
|
|
</td>
|
|
|
</tr>
|
|
|
<tr style='height:19.85pt'>
|
|
|
<td width=110 style='width:65.7pt;border:solid windowtext 1.0pt;border-top:
|
|
|
none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>Tr3</p>
|
|
|
</td>
|
|
|
<td width=168 style='width:100.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>40V</p>
|
|
|
</td>
|
|
|
<td width=143 style='width:85.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>47mA</p>
|
|
|
</td>
|
|
|
<td width=183 style='width:109.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>475mW</p>
|
|
|
</td>
|
|
|
<td width=193 style='width:115.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>575mW</p>
|
|
|
</td>
|
|
|
</tr>
|
|
|
<tr style='height:19.85pt'>
|
|
|
<td width=110 style='width:65.7pt;border:solid windowtext 1.0pt;border-top:
|
|
|
none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>Tr4</p>
|
|
|
</td>
|
|
|
<td width=168 style='width:100.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>23V</p>
|
|
|
</td>
|
|
|
<td width=143 style='width:85.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>0.41mA</p>
|
|
|
</td>
|
|
|
<td width=183 style='width:109.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>6mW</p>
|
|
|
</td>
|
|
|
<td width=193 style='width:115.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>8mW</p>
|
|
|
</td>
|
|
|
</tr>
|
|
|
<tr style='height:19.85pt'>
|
|
|
<td width=110 style='width:65.7pt;border:solid windowtext 1.0pt;border-top:
|
|
|
none;padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>Tr5</p>
|
|
|
</td>
|
|
|
<td width=168 style='width:100.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>39V</p>
|
|
|
</td>
|
|
|
<td width=143 style='width:85.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>50mA</p>
|
|
|
</td>
|
|
|
<td width=183 style='width:109.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>985mW</p>
|
|
|
</td>
|
|
|
<td width=193 style='width:115.95pt;border-top:none;border-left:none;
|
|
|
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
|
|
|
padding:0cm 0cm 0cm 0cm;height:19.85pt'>
|
|
|
<p align=center style='text-align:center'>2W</p>
|
|
|
</td>
|
|
|
</tr>
|
|
|
</table>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<p><span style='font-size:6.0pt'> </span></p>
|
|
|
|
|
|
<p align=center style='text-align:center'>Table 2. Maximum voltage, current and
|
|
|
power for transistors in a 1996 design.</p>
|
|
|
|
|
|
<p> </p>
|
|
|
|
|
|
<p>Before I get any queries, please note that the maximum power, under load, does
|
|
|
not coincide with the maximum voltage or the maximum current, therefore the
|
|
|
power figures cannot be derived from the multiplication of columns 2 and 3.</p>
|
|
|
|
|
|
<p> </p>
|
|
|
|
|
|
<p> </p>
|
|
|
|
|
|
<p><b><span style='color:blue'><a href="index-1.htm" title=index-1.htm>[ Back
|
|
|
to Index ]</a></span></b></p>
|
|
|
|
|
|
<p> </p>
|
|
|
|
|
|
<p> </p>
|
|
|
|
|
|
<p><b><span style='font-size:8.0pt'>HISTORY:</span></b><span style='font-size:
|
|
|
8.0pt'><EFBFBD><EFBFBD> Page created 01/05/2001</span></p>
|
|
|
|
|
|
<p><span style='font-size:8.0pt'>22/05/2001 2N3019 added </span></p>
|
|
|
|
|
|
<p><span style='font-size:8.0pt'>27/05/2001 Reference to BD139-16 added</span></p>
|
|
|
|
|
|
<p><span style='font-size:8.0pt'>09/09/2001 Caution regarding high ft output
|
|
|
transistors added</span></p>
|
|
|
|
|
|
<p><span style='font-size:8.0pt'>07/11/2001 Notes re MJ15003 and MJ802 added</span></p>
|
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|
|
<p> </p>
|
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</div>
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</body>
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</html>
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