What triggers Yamaha AVR protection circuit

[jagdish_p]

Hi,
Recently my AVR tripped a couple of times.
I have connected the preouts of the yamaha AVR to the amp section of my Arcam integrated amp for driving the front left and right speakers. My AVR tripped a couple of times when I was playing a movie which had low sound level forcing me to to turn up the AVR volume to 0 dB. I was using the AVR in stereo mode which means that the Amp section of the AVR is not being used at all as the pre out of the AVR is fed to the Arcam Amp and front speakers are not connected directly to yamaha AVR.

So why did the AVR trip - does the protection circuit also monitor the pre amp amplification?

 

[jagdish_p]

Re: What triggers Yamaha AVR protection circuit?

78 views and no reply
Is my query stupid or complicated

My thoughts:

a) if the protection circuit is triggered by high current then my AVR should not have tripped as I was not using the amplification section - only pre outs being used
b) even if there is a protection circuit for pre amp output signal it should not tripped as I did not play at very high decibel level .I only increased the volume setting to off set the weak input audio signal
c) the above makes me conclude that the protection circuit also monitors the multiplication of the signal.

Is my thinking correct?

 

[hydrovac]

Matching Amp to Preamp with the voltage gain. Simply, it is the degree to which an amplifier actually amplifies the input from the preamplifier/processor. Often overlooked by those unaware of its importance, this one parameter can have significant implications on actual performance when an amplifier is introduced into an AV system. Understanding the impact that different levels of voltage gain can have in your system can very well be the difference between poor sound and getting the most out of an external amplifier.

Naturally too much or too little of anything can present a problem, and the ideal amount of voltage gain can vary depending on a few factors. Utilizing a receiver with poorly implemented preamplifier outputs for example can be a problem when coupled to a high powered amplifier with relatively low voltage gain and consequently a high input sensitivity, which is the amount of voltage needed from the preamp to drive the amplifier to full unclipped power. Suppose you have a receiver that can deliver 1 volt RMS from its preamplifier outputs before clipping; if you pair this receiver with a high powered amplifier expecting a huge boost in headroom, you might be sorely disappointed if its voltage gain is a below average 27dB.

A gain of 27dB equates to a ~22.6x increase in voltage, meaning our amplifier will be putting out 22.6 volts RMS, or a whopping 64 watts into an 8 ohm load before our AVRs pre-outs run out of gas. Even if the amplifier is rated to deliver 1,000 watts, all youre going to do when you push harder is get garbage as your AVR clips the signal to the amplifier or potentially trip its protection circuits. Long story short: if you want to add power to a lower end receiver with pre-outs, you probably want something with a better than average amount and a low input sensitivity.

Reading the above, it may seem that those who seek the additional output of an external amplifier are caught in a vicious catch 22. Certainly if you happen to have a combination of an AVR with a poor preamplifier output section combined with ultra-high sensitivity loudspeakers, you may want to reconsider some of your hardware choices; beyond that, careful selection can help ensure that you get the most out of your equipment. Further, it should be noted that low end receivers may not be the ideal starting point for adding separate amplifiers.

 

[jagdish_p]

Matching Amp to Preamp with the voltage gain. Simply, it is the degree to which an amplifier actually amplifies the input from the preamplifier/processor. Often overlooked by those unaware of its importance, this one parameter can have significant implications on actual performance when an amplifier is introduced into an AV system. Understanding the impact that different levels of voltage gain can have in your system can very well be the difference between poor sound and getting the most out of an external amplifier.

Naturally too much or too little of anything can present a problem, and the ideal amount of voltage gain can vary depending on a few factors. Utilizing a receiver with poorly implemented preamplifier outputs for example can be a problem when coupled to a high powered amplifier with relatively low voltage gain and consequently a high input sensitivity, which is the amount of voltage needed from the preamp to drive the amplifier to full unclipped power. Suppose you have a receiver that can deliver 1 volt RMS from its preamplifier outputs before clipping; if you pair this receiver with a high powered amplifier expecting a huge boost in headroom, you might be sorely disappointed if its voltage gain is a below average 27dB.

A gain of 27dB equates to a ~22.6x increase in voltage, meaning our amplifier will be putting out 22.6 volts RMS, or a whopping 64 watts into an 8 ohm load before our AVRs pre-outs run out of gas. Even if the amplifier is rated to deliver 1,000 watts, all youre going to do when you push harder is get garbage as your AVR clips the signal to the amplifier or potentially trip its protection circuits. Long story short: if you want to add power to a lower end receiver with pre-outs, you probably want something with a better than average amount and a low input sensitivity.

Reading the above, it may seem that those who seek the additional output of an external amplifier are caught in a vicious catch 22. Certainly if you happen to have a combination of an AVR with a poor preamplifier output section combined with ultra-high sensitivity loudspeakers, you may want to reconsider some of your hardware choices; beyond that, careful selection can help ensure that you get the most out of your equipment. Further, it should be noted that low end receivers may not be the ideal starting point for adding separate amplifiers.

Took me a while to understand all aspects of what you posted. Thanks a lot for the detailed explanation.
I added the Amp into the 5.1 system for the sole reason of using the same front speakers for stereo and 5.1. I am happy with the stereo set up when I play directly from my integrated Amp.

Only for certain files while watching movies through AVR --> Amp--> fronts I have issues.

So the Yamaha receiver trips when the preout signal starts clipping.Yamaha pre out levels are low. I guess I need to rethink on the set up to avoid this.
Thanks a lot