The Class-A Amplifier Site
This page was last updated on 1 May 2004
The JLH Class-A Amplifier
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Index
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Last Updated |
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The JLH Class-A Articles
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The Original Article - Wireless World April 1969
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Oscilloscope Traces & Photographs from the 1969 Article
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Letter to the editor - Wireless World October 1969
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The Postscript - Wireless World December 1970
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The Update - Electronics World September 1996
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A Little Reminiscing - Electronics World May 2000
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16kB |
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Power Supplies for the JLH Class-A
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An updated, regulated power supply for the 1996 version
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1 May 2004 |
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A Current Boosted LM317/LM337 Regulator
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14 October 2001 |
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17 May 2001 |
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17 May 2001 |
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Additional Information for the JLH Class-A
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JLH Class-A - Single-ended or Push-pull?
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23kB |
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17 August 2003
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A JLH Class-A for the Quad ESL57
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4 February 2002 |
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27 November 2002 |
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7 November 2001 |
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D C Voltages (for testing / fault-finding)
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7 May 2001 |
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7 May 2001 |
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Constructors’ Comments – Sound Quality
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5 December 2001 |
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Contributed Articles
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A Dutch journey in JLH-land (By Rudy van Stratum)
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19 August 2001 |
HISTORY: Page created 04/04/2004
04/05/2001 The April 1969 Original page, photographs and oscilloscope traces moved to separate pages
07/05/2001 Simulation Results, Earthing and DC Voltages pages added
10/05/2001 Quiescent Current and DC Offset page added. Link added to Design Notes page
11/05/2001 Comparison of Versions and Transistors moved to separate page. Simulation Results re-titled Simulations
13/05/2001 A Simple Voltage Regulator page added
16/05/2001 Diagram and equation corrected in A Simple Voltage Regulator page
Diagrams in Updated Regulated Supply and Design Notes pages redrawn
Diagrams corrected in The Capacitance Multiplier page and simple capacitance multiplier circuit added
17/05/2001 Recommended capacitor sizes updated in The Capacitance Multiplier page
Minor text changes and second voltage equation added to A Simple Voltage Regulator page
19/05/2001 Comparison of Versions and Transistors page temporarily withdrawn
20/05/2001 Comparison of Versions and Transistors page reissued
22/05/2001 2N3019 added to Transistor Substitutes page
26/05/2001 New link added to JLH Links page
27/05/2001 Para 2 and simulation results for Tr5 added to Comparison of Versions and Transistors page
Reference to BD139-16 added to Transistor Substitutes page
05/06/2001 Design Notes page, polarity of C3 in Figure 2 corrected
24/06/2001 Constructors’ Comments – Sound Quality page added
08/07/2001 Constructors’ Comments – Sound Quality page updated
24/07/2001 Constructors’ Comments – Sound Quality page updated
01/08/2001 New link added to JLH Links page
05/08/2001 Design Notes and Constructors’ Comments – Sound Quality pages updated
14/08/2001 JLH new power supply page updated
18/08/2001 Constructors’ Comments – Sound Quality page updated
19/08/2001 Rudy van Stratum’s article added
09/09/2001 Caution regarding high ft output transistors added to Transistor Substitutes page
Figures for MJL3281A removed from Comparison of Versions and Transistors page
14/09/2001 Constructors' Comments - Sound Quality page updated
14/10/2001 Current Boosted LM317/337 Regulator page added. JLH Links page amended
04/11/2001 JLH Class-A for the Quad ESL57 page added
07/11/2001 Transistor Substitutes page updated
18/11/2001 JLH Class-A for the Quad ESL57 page updated
19/11/2001 JLH Class-A for the Quad ESL57 page updated
21/11/2001 JLH Class-A for the Quad ESL57 page updated
22/11/2001 JLH Links page updated
05/12/2001 Constructors' Comments - Sound Quality page updated
31/01/2002 Resistor power rating notes added to JLH for ESL57 and Design Notes pages
04/02/2002 Resistor power rating notes on JLH for ESL57 page revised
27/11/2002 JLH Class-A Update page added. Design Notes page amended
Links and redundant pages deleted
28/11/2002 JLH Class-A Update page amended
15/03/2003 Addendum added to JLH Class-A Update page
17/08/2003 JLH Update page amended
02/04/2004 A Little Reminiscing and JLH Class-A Single-ended or Push-pull pages added
01/05/2004 Updated Regulated Supply page amended