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Soldering

The article ‘Your Guide To Soldering’ by K. Bharathan published in May issue was very good and informative.

Prajyot the link from where I can download these circuit diagrams. Anirvan Kolkata EFY: You may visit www.efymagonline. com to purchase the respective issues.

amplifier Using TDa2005M

In the ‘Guitar and Microphone Amplifier 8sing TDA2005M’ circuit published in May issue, please note that:

1. Depending on the intended application of the circuit:

(a) The value of C3 can be reduced and selected in the range of 1-10 nF. This will reduce suppression of high frequencies from the microphone.

(b) If electrolytic capacitors C2, C4 and C5 have high leakage currents, these can be replaced with non-polarised capacitors of the same values.

( c) The value of potentiometer 9R1 (2.5-kilo-ohm) can be reduced to 100-680 ohms.

2. If switch S1 is opened, the microphone is not powered.

3. If the guitar does not have an internal preamplifier or buffer, the cable between the guitar and connector CON1 should not be more than 1.8 metres long. —Petre Tzv Petrov, the author of ‘Guitar and Microphone Amplifier

8sing TDA2005M’