Build a Home Theater Amp: Voltage & Current Ranges

In summary, the conversation discusses the voltage range for audio outputs on devices like DVD players and processors, as well as the typical current or voltage range for speaker connections. The line level for stereos is typically .35 - .5 V RMS, while the output can vary depending on the brand and power margins. For 50W into a 6 ohm speaker, the V+ and V- should be around 38V and -38V respectively. It is also suggested to obtain power supply parts from old stereos.
  • #1
JerryG
58
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I am interested in attempting to build a home theater amplifier, but I have a few questions. What is the voltage range from the audio outs on something like a DVD player or processor? Also, what is a typical current or voltage range from the speaker connection terminals?
 
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  • #2
  • #3
Hey Jerry,

Welcome on.

The line level commonly quoted level for stereos is about .35 - .5 V RMS. Since the volume control operates in dB, it has a HUGE range of control and this doesn't make much difference.

As for the output, that gets tricky. Some brands lie, some scrape by, and some have large power margins. Generally, I left about 25% over my target value at the target speaker impedance.

For 50w, P=V^2 / R => V^2 = PR => V=sqrt(PR)
For 8 ohms, Vrms=20Vrms
For your inside power supply, V+/V- = Vrms * sqrt (2) * 125% + transistor drop
For 8 ohms, V+ = 38V, V- = -38V.

Power supply parts are most easily obtained from busted stereos.

Good Luck,

- Mike
 

Related to Build a Home Theater Amp: Voltage & Current Ranges

1. What is the difference between voltage and current in a home theater amp?

Voltage and current are two important electrical properties that are used to power a home theater amp. Voltage is the measure of the potential energy between two points in an electrical circuit, while current is the flow of electrical charge through a circuit. In simpler terms, voltage is the force that moves the electricity, while current is the amount of electricity that is actually moving.

2. What voltage range should I look for in a home theater amp?

The voltage range of a home theater amp will depend on the specific model and its power requirements. However, most home theater amps will operate within a voltage range of 110-120 volts for North America and 220-240 volts for Europe and other countries. It is important to check the manufacturer's specifications for the specific voltage range of your amp.

3. How does the voltage affect the performance of a home theater amp?

Voltage plays a crucial role in the performance of a home theater amp. A higher voltage will typically result in a louder and more powerful sound output, while a lower voltage may result in a weaker sound. However, it is important to note that the wattage and efficiency of the amp also play a role in the overall performance.

4. Can I use a home theater amp with different voltage ranges in different countries?

It is possible to use a home theater amp in different countries with different voltage ranges, but it requires a voltage converter. This device will convert the voltage of the country you are in to the voltage range that your amp requires. However, it is important to note that using a voltage converter may affect the performance of your amp, so it is best to check with the manufacturer before doing so.

5. How can I ensure the safety of my home theater amp's voltage and current?

To ensure the safety of your home theater amp, always make sure to use the correct voltage range as specified by the manufacturer. Using a voltage range that is too high or too low can damage your amp and potentially cause harm. It is also important to use a surge protector to protect your amp from power surges and fluctuations. Regularly checking the power cords and connections for any damage or wear can also help maintain the safety of your amp's voltage and current.

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