100 Circuits - Audio 1 E-Book

Newton C. Braga

• Herausgeber: Editora NCB
• Kategorie: Wissenschaft und neue Technologien
• Serie: Circuit Bench
• Sprache: Englisch

Seitenzahl: 76

Veröffentlichungsjahr: 2017

Beschreibung

During the long career of the author as a writer of technical articles and books, he have on several occasions addressed the theme "collection of circuits", also including information. Thus, previously, addressing this theme, he published the series "Circuits and Information" (7 volumes) and "Circuits and Solutions" (5 volumes) containing hundreds of useful circuits and technical information of all kinds. The series has run out, time has passed, but readers still charge us something similar updated and that can still be used in projects of all kinds. In fact, basic circuits using ordinary discrete components, from transistors to integrated circuits, are still widely used as simple solutions for immediate problems, part of more advanced projects and even for didactic purposes, at the request of a teacher who needs an application for a theory. So, he is back with this series, but with a differentiated structure, new projects and a new approach. The difference in approach will be to divide the various volumes of the series by themes, we will have audio circuits,such as amplifiers, preamplifiier, mixers, etc. In his stock of circuits, collected from all possible sources, he already have more than 12,000 of them, many of which can be accessed in a dispersed way in the site of the author. The advantage of having these circuits organized in volumes, besides access anywhere, is in the easy location of a circuit. The information, on the other hand, will be added to the circuits, with internal links, which is only possible in a digital publication. Most of these circuits, collected in publications that, in some cases, may not be very current, receive a special treatment with comments, suggestions and updates that make possible its execution even in our days.

Leseprobe

Newton C. Braga

Circuit Banch - volume 1

100 Audio Circuits - 1

1a EDITION

São Paulo - 2017

Instituto NCB

www.newtoncbraga.com

[e-mail]

Director: Newton C. Braga

Designer: Renato Paiotti

CIRCUIT BENCH – V2 – 100 AUDIO CIRCUITS

Author: Newton C. Braga

São Paulo - Brasil - 2017

Key words: electronics – audio - circuits

More Informations

INSTITUTO NEWTON C. BRAGA

http://www.newtoncbraga.com.br

Índice

Introduction

1) Simple mixer

2) Bass and Treble Control

3) RIAA Preamplifier

4) Parametric Equalizer

5) Super-Bass Amplifier

6) CMOS Mixer

7) Microphone Booster

8) Pre Amplifier for Crystal Microphone With 741

9) Magnetic Pickup Preamplifier Using the 741

10) General Purpose Preamplifier

11) Bass-Booster Preamplifier with 741

12) Preamplifier for Magnetic Microphones with 741

13) Preamplifier for Low Impedance Microphone

14) Low Impedance Preamplifier

15) RIAA Preamplifier Powered By USB

16) Simple Preamplifier Simple

17) Simple Preamplifier II

18) Preamplifier with Several Gains

19) Cassette Recorder Preamplifier

20) Microphone Preamplifier II

21) Preamplifier for Low Impedance Microphone II

22) Active Tone Control with the 741 IC

23) RIAA Preamplifier II

24) Bass, Middle, and Treble Control with 741

25) NAB Preamplifier

26) High Impedance Preamplifier

27) Microphone Preamplifier

28) Scratch Filter forTurntable

29) Rumble Filter

30) Bass Boost

31) Noise Limiter

32) Preamplifier with Virtual Ground

33) Audio Limiter

34) Active Crossover

35) Parametric Equalizer II

36) Audio Booster

37) Audio Switch

38) Rumble Filter II

39) Scratch Filter II

40) Medium Control

41) 60 Hz filter

42) Audio Preamplifier

43) RIAA Preamplifier III

44) General Purpose Preamplifier II

45) Universal Preamplifier for Microphone

46) Transistor Amplifier Stage

47) Voice Booster

48) Low Impedance Microphone Preamplifier III

49) Sub-Woofer Filter

50) Bass, Middle and Treble Control II

51) 700 mW amplifier with LM386

52) Telephone amplifier with LM386

53) Class A Amplifier - 10 W

54) Small Amplifier

55) Complementary Mini Amplifier

56) Small Amplifier for Microphone - LM386

57) Headphones Amplifier

58) 1.5 W Transistor Amplifier

59) 3-W Amplifier with MOSFET

60) Amplifier using the LM380 IC

61) Low power transistor amplifier

62) Transistor Amplifier with the BC548-BC558

63) Old Transistor Amplifier

64) High Quality Amplfier for Headphones

65) Darlington Audio Stage

66) 4-Watt Transistor Amplifier

67) 1-W Transistor Amplifier

68) General Purpose Phone Amplifier

69) Amplifier for Earphones II

70) Headphones Amplifier III

71) 1-W Headphones Amplifier

72) Mini Amplifier

73) Bridge LM388 Amplifier

74) MOSFET Power Stage

75) 5.5 W Amplifier - LA4420

76) Stereo Headphones Amplifier

77) Amplifier with 741 - I

78) Amplifier with 741 - II

79) Audio Power Amplifier with 741

80) 280 mW amplifier with 741

81) Two-Transistor Amplifier

82) Amplifier for Telephone Pickup

83) Amplifier for Telephone Pickup - II

84) Telephone Amplifier with TDA7052

85) 280 mW Amplifier Using the 741 OA – II

86) Small Amplifier

87) PWM Amplifier (Class D)

88) Amplifier V 5 x 60 mW - TTL

89) Megaphone

90) Power Stage with TIP31

91) M150 Amplifier- Ibrape

92) 10 W Transistor Amplifier

93) 10 W-Transistor Amplifier II

94) Hybrid Amplifier - 10 or 20W

95) 15W MOSFET Amplifier

96) 7W Amplifier with LM383

97) Class A Amplifier - 2N3055

98) LM386 Amplifier with 741 Preamplifier

99) Transistor Amplifier - TIP31 / 32

100) 5 W Amplifier - TIP31-TIP32

Information about the Principal Components

FET - TRANSISTOR – TUBE

Introduction

The term “Circuit Bench” was used many times along our long career as a technical writer of books and articles all over the world. So, prior this serie, based in this theme we had published two book collections in Brazil: “Circuits and Informations (Circuitos e Informações) – 7 volumes and “Circuits and Solutions (Circuitos e Soluções – 5 volumes). These collections gathered hundreds of circuits and useful information about components, design, formulas and tables. The series are out of print now but our readers are asking us for something like that to be used in electronic projects of all kind. In fact, basic circuits using common discrete componentes such as transistors and Ics are today used as fast solutions for imediat problems, part of more advanced projects, as shields for microcontrollers and with didatic purposes for a school work or demonstration. So, we returned with this serie, but with a different approach and new projects. The different approach is the division of the volumes by themes. So, in this second volume the circuits gathered had audio as main subject. In fact, since we have in our collection more than 12 000 circuits many, of then can be found in our site, but following no organization. The advantage for the reader is that in this book the circuits are organized by subject and even complentary articles will be given. More part of the circuits was found in publications and magazines that don’t exist anymore and are not current since the components are hard to find. Suggestions about the use of equivalents and even how to find them by sources, such as Mouser Electronics, will be included. Finally we can say that in this serie we will give to the readers the opportunity to have in their tablets, Iphones, Ipads and PCs a powerful source of ideas for projects and informartions.

Newton C. Braga

1) Simple mixer

This is 4-input audio mixer using an integrated circuit 741 and two more operational amplifiers. The characteristics of the inputs are given by the diagram. The power supply of the integrated circuits must be symmetrical with 6 to 12 V. The input leads and output audio signals must be shielded. The resistor 741 between the output and the inverting (-) input determines the loop gain. The NE5534 and TL081 operational admit equivalents. For the TL081 can be used CA3140. The circuit has the following features:

Input 1 - maximum gain of +6 dB and 10k input impedance - source: line

Input 2 - maximum gain of 20 dB, and input impedance of 5 to 10 k - source: line

Input 3 - maximum gain of 46 dB and input impedance of 1 k ohms - source: low impedance microphone

Input 4 - maximum gain of 6 dB and input impedance 1 M ohms - source: high impedance microphone

We also recall that the cable inputs and signal outputs must be shielded, and the pots must be of logarithmic type. As a possible modification, one or more inputs can be eliminated, if not used in the desired application.

2) Bass and Treble Control

This circuit can be added to any audio amplifier design, consisting of a good tone control with an operational amplifier. The operational amplifier may be the 741 or equivalent and the power supply is symmetrical or dual. The circuit is placed between the signal source and the amplifier input. The pots used should be linear. Note that the input cables and output signals must be shielded. For a stereo version must be mounted two identical units, one for each channel. As consumption is very low, the power can be obtained from own amplifier with which the control will work. Anyway, it is very important to add a good filter to prevent any noise. For the stereo version, double operationals such as the LM1448 or LM1548 may be used.

3) RIAA Preamplifier

This circuit should be placed between a turntable and recorder or playback media from the input to equalize the old vinyl records curve matching it with modern equipment. Among the possible applications we suggest the conversion of old media (vinyl records) to modern media such as MP3, CD, etc. The circuit must have symmetrical power supplty and the operational may be the 741. An excellent filtering is important to prevent any noise. Input cables and output signals cables must be shielded also to prevent noise. 4658 is a double 741 and the brackets are for the other channel using the same integrated. Can be used other equivalent to the 741 as the MC1458. The capacitor of 10 μF to 1k resistor must be of tantalum, for higher gain stability. When assembling is also important that the board is designed so that the distances between the components as small as possible. We recall that the RIAA equalization attenuates differently frequencies of the audio track to match the characteristics of recording of vinyl records. Thus, in the reproduction this attenuation should be undone so that the sound recovers its original characteristics, which is achieved with the aid of this circuit.

4) Parametric Equalizer

This circuit should be placed between the signal source and the input of a recorder or amplifier. The amplifiers may be of the type 741 with symmetrical power source and shielded signal cables. The equalization of frequency bands are indicated next to each block. In this type equalizer, the attenuation and reinforcement of each frequency band can be adjusted separately. In this circuit specifically we have 5 channels, whose frequencies are indicated next to each adjustment pot, which should be linear. Operatinal are simple type 741, but can be used double versions. The power supply must be symmetrical 6 + 6 + 15 V to 15 V with excellent filtering. A source of about 100 mA is sufficient to power the circuit since its consumption is very low. For a stereo system, they must be installed two units as this, one for each channel. The power supply can be only one.

5) Super-Bass Amplifier