The Gainclone. Introduction: Background Info: Construction Notes. Introduction. The model Gaincard from 47 Laboratories is a 25 Watt stereo amplifier. Check for Samples: LM The LM is a high-performance audio power LM to reduce the effects of PCB trace resistance and inductance. PCB for 56W Audio Amplifier using LM HiFi Amp. For LM IC. High quality FR4 double-sided, plated-thru and tinned holes, with conformal coating.

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The model Gaincard from 47 Laboratories is a 25 Watt stereo amplifier about lm375 size of a video cassette, powered by a large external supply. The capacitor C5 is connected to R6 help lower frequency to -3dB at frequency about 10Hz. It is not a bad idea to add a switch on the rear of the amplifier, whereby the star i.

LM – Power amp kit

The most important thing is to make sure that all internal wiring is properly done. Sound signal is amplified and then come out the pin 3 of IC.

The actual layout of the circuit board could be something like this: Attenuator is ladder type. Rather than using one board for stereo, you will need 2 boards, each one running in a parallel mode. Typical operation, from the LM datasheet: Soft recovery types are probably the best bet. This requires 2 boards 4 amplifiers lm875 speaker, plus a DRV board.

The Gainclone

The use or copying of the contents of this page, in whole or in part, for any commercial purpose is expressly prohibited. From stereophile Z in data. An example of a circuit that could do this would be using a Texas Instruments DRV chip to invert one of the two non-inverted amplifiers. Please note that I will be using the component numbering used here throughout this page, so refer back to this diagram as needed.


Construction Notes Introduction The model Gaincard from 47 Laboratories is a 25 Watt stereo amplifier about the size of a video cassette, powered by a large external supply. The National Semiconductor’s Overture series of integrated circuit IC audio amplifiers owes its rise to ‘fame and glory’ to a relatively big success of the 47 Laboratory’s Gaincard amplifier, based on the LM chip from the National Semiconductor. A 50 kOhm volume potentiometer could be substituted.

This resistor can also be omitted in most cases, which is best determined experimentally. Figure 1 The amplifier schematic is shown in Figure 1. This circuit is very l3m875 for a small hifi system in house, with medium overall specifications.

The left-channel audio signal is connected to the input, to resistor R2 act as set the impedance of circuit is 33K through lk3875 coupling capacitor C2. The IC include circuitry to block a lot, for example, prevent a spike or block the signal of the power circuit, short circuit protection and output over voltage protection circuit, out of voltage or overload.

This page dates back to the beginning when the Gaincard was literally a black box. This image is pcbb be used as a guide while assembling.

To connect the output of the amplifier to the speaker output terminals, a thicker solid or stranded wire should be used while high-quality shielded cables should be used for input signal wiring. Top Background Information Some things we know for sure: This article focuses on a tried and true low-power amplifier 30W with the IC LM, originally intended for the design and testing of active speaker systems.


Figure 1 The pins using of LM There are some km3875 further: This site uses Akismet to reduce spam. If you are planning on driving 4-ohm speakers, use one board per speaker, with the positive outputs wired together.

And its its an easy and safe project to build. Parallel mode allows the amp module lm3785 drive a 4-ohm load at W. C2 is most likely also omitted. Figure 2 the internal circuit in LM I also compared it with a Ocb x 6 home theater amp, and the home theater amp in stereo modewas able to reach higher volume without distortion, but they were very close in sound quality.

LM3875 Gain Clone Amplifier Project

When the DRV board is finished, you simply connect the input to it, and one of it’s two outputs to both l,3875 inputs. It will be done soon though. C1 should be included to protect your speakers but can be omitted if you know your source components are not DC lm375 at the output. Power cord is captive four pin molex, one per channel. Please download the freeware version of Eagle Layout editor from here to view any pcb file on this website.

You wire the two boards using the parallel mode schematic. LevHyp 19 May Reply.