Manuals / Ramsey Electronics / Home Audio / Stereo Amplifier

Ramsey Electronics BN9 manual Microphone And Audio Input Consideration, Gain Considerations

Models: BN9 2 1/2 Watt Super Sleuth Audio Amplifier

1 16
Download 16 pages 50.13 Kb
Page 8
Image 8

MICROPHONE AND AUDIO INPUT CONSIDERATION

You may choose almost any transducer to convert sound into an electrical signal for your BN9. Some of the transducers are as follows; ceramic, crystal, dynamic, or even another speaker! You may also use audio from any other source as well (other than a zillion watt per channel power amp!)

GAIN CONSIDERATIONS

In applications where you don't need so much gain, such as amplifying earphone outputs, you may wish to omit the pre-amplifier stage. This is done by removing (or just plain not installing) the preamp transistor and substituting a jumper (made from a scrap component lead) for R1. This allows you to still get the full 2 1/2 watts of audio output but reduces the total gain to 50. There is no point in feed- ing the LM380 more audio signal, it just results in poorly distorted audio with no additional power out- put gained.

TROUBLESHOOTING

Problem: LM380 gets really hot, and then quits!

Solution: Cool your jets! You are probably running maximum voltage and maximum power for too long. Either reduce the voltage to 10-12 volts or reduce your volume level. You may need to replace the LM380.

Page 7 Page 9
Page 8
Image 8
Ramsey Electronics BN9 manual Microphone And Audio Input Consideration, Gain Considerations, Troubleshooting
Page 7 Page 9

FAQ

What types of transducers can be used with the BN9 amplifier?

You may choose almost any transducer to convert sound into an electrical signal for your BN9, including ceramic, crystal, dynamic, or even another speaker.

How can I reduce gain in the BN9 amplifier?

In applications where you don't need so much gain, such as amplifying earphone outputs, you may wish to omit the pre-amplifier stage by removing or not installing the preamp transistor and substituting a jumper for R1.

What should I do if the LM380 gets really hot and then quits?

If the LM380 gets really hot and then quits, you are probably running maximum voltage and maximum power for too long. Either reduce the voltage to 10-12 volts or reduce your volume level. You may need to replace the LM380.