The manuals for RX-3080, A4/6/8 all say 2V for pre-outs.
On the ASR refurbished 3080, what was the max pre-out voltage?
Amir said on the RX-A1080 that he had to set the volume to +2dB to get 2V = 0.004% THD+N, instead of setting the volume to 0.0dB?
If he left the volume at 0.0dB, it would be 1.57V?
1.6V = 202W (28dB gain), 127W (26dB gain).
Seems funny how the RX-A1080 THD+N is 0.004%, but the Refurbished RX-A3080 is 0.008%. Shouldn’t the THD+N be higher if you increase volume from 0.0dB to 2.0dB?
Did he increase the volume on the RX-A3080 by 2dB to get 2V?
No idea, either that unit had an issue, but I think more likely there was just something silly going on during that test. He should have investigated as he had done in the past if something weird happened but in this case I guess he didn't bother because the owner was only interested in getting the amp tested. He sort of clarified this morning.
Regarding the specs, when you see something like:
1 V/470 ohm
Maximum 2 V
such as Yamaha's, it does not mean it can sustain at the maximum level. So it is possible that Amir was trying to do a sweep like Gene did with the RX-A860 and that triggered the protection mode. Even the Marantz SR8012 couldn't deal with such sweep test well.
Amir came across that too when he measured the RX-A1080. So if I were to bet money on this, I would say that was what happened.
Obviously the A6A listened (to Gene?) and have softened the protection mode approach on the new generation. Again, I am
only speculating.
I know we are not talking about Marantz, but I thought it may help to review what Gene found on this protection mode thing in the following link, I use the SR8012 as example because he elaborated more on that test than the one he did on the Yamaha RX-A860.
Marantz SR8012 Bench Tests & Conclusion | Audioholics
Editorial Note about Preamp Mode:
I was unable to do a preamp frequency sweep exceeding 1.2Vrms as it tripped the protection circuits since the power amps were still engaged and exceeded full rated power (140 watt/ch, 8 ohms, Av = 29dB). Unfortunately, Marantz doesn't offer a preamp only mode to disconnect the power amp from the circuit if you're using only external amplification. This is something I'd like to see ALL receiver manufacturers offer that include preouts to avoid this very problem I noted. It would also be more energy efficient as well. We will be testing this on receivers going forward and lobbying the manufacturers to include a preamp mode if they already don't. Please note it's unlikely you will ever run into a problem driving external amplification as normal program material doesn't behave like continuous sinusoidal sweeps like what was used on my bench tests.
Also note that he didn't have that issue with the SR8015, so again may be like Yamaha, manufacturers are beginning to pay attention to feedbacks from bench tests done by independent labs, thanks to Gene and Amir.
In the real world though, I would still say flagship AVRs like the RX-A3080, even 2080 will not trip on protection for 99% of their users, only the 1% who asked for it may get it.
