TDA 7377 for PA application

[Aby Raj]

Hi friends..I need some help regarding the car amplifier IC TDA7377 and some related doubts. My aim is to amplify a mono signal input from a dynamic mic pre-amplifier/ line input and to drive a 8 ohms 40 W speaker or two of them in parallel. I am basically looking for a portable PA application using 12 volts.

This is what the datasheet shows...






Now, these are my doubts.


1) If I just drive a mono signal to both the left and right channels in the double bridged configuration, will that affect something like phase ???

2) What is the best possible solution for using this amplifier for mono signal.


4) Suppose I want to drive a horn speaker (10-25W, 8 ohms) can I connect it directly to the mono output???


3) I have seen that some commercial PA amp companies in India like Ahuja use discrete components rather than ICs, even for a 20Watts megaphone. What's the probable reason behind that ??

 

[betwixt]

1. Double bridge should work fine, use two speakers, one on each output and link the inputs together before the couplng capacitors.
2. Double bridge is best, it uses fewer components and gives more power out.
4. The type of loudspeaker is not important as long as it's impedance isn't lower than allowed. (lower impedance = heavier load on the amp)
3. Where quality and availability of parts might be a problem, discrete components are often a better solution. For example you may be able to use alternative output transistors with the same results but if you can't get the IC your production stops.

Brian.

 

[KlausST]

Hi,

I am basically looking for a portable PA application using 12 volts.

Do you think this amplifier is suited for an portable AMP.
It draws much quiescent current and drains out your battery.
(Isn´t it obsolete? Or is it still produced?)

Maybe have a look at Class D amplifiers. Like TPA3116.

Klaus

 

[Aby Raj]

Thanks Brian...

that solved a lot of confusion....



Hi Klaus,

Your advice prompted me to check the quiescent current of two commercial PA amplifiers, out of curiosity. That 20 Watt megaphone which I mentioned before consumes 70-80 mA of current at standby state. Usually we use it for a long day using 8 D cells at full sound power. Then I tested another amp of 30 W, that used a 12v 1.2 Ah battery and seems to drain out at a very fast rate. It consumes 250mA at standby state.

It seems 7377 is not obsolete like 7374. These ICs are popular around my local area rather than the TPA3116. I had this lying around for sometime and wished to do something with it. Anyway, I'll look out to see for any other chips available around here, that may perform better than the 7377.

Aby

 

[Audioguru]

The TDA7377 is not made anymore and is not available in North America, maybe because they lied about its output power and its idle current is (was) too high.
It was rated at 35 WHATS per bridged channel into 4 ohms when powered by a 14.4V overcharging car battery when its input and output are a saturated squarewave.

Its real power was only 12 Watts to 14 Watts per bridged channel into 4 ohms just before clipping when powered from 12V or about 6 Watts to 7 Watts per bridged channel into 8 ohms.