I think I will sell my separate amp, and never come back to them. Here is the story:
My audio system 5.1 consists of speakers in front Dynaudio Contour 30, center Dynaudio Evoke 25c, rears Dinaudio Evoke 10. AVR Arсam AVR10 and Anthem MСA 50 amp. All speakers are connected to MCA 50.
Recently, sound disappeared in one of the rear channels on the amplifier, I immediately rearranged the cable to the receiver and noticed a large increase in volume (I thought it might be due to the fact that only one small rear speaker with a small load connected to AVR). But I decided later to compare the sound of AVR and AMP. Now is all 5 channels work fine on amp.
I am comparing devices using Cd/Aux Stereo Switch box and Speaker Switch Box and SPL meter,AVR in Direct mode. The methodology is as follows, my ears are 1-1.5m from the speaker, one hand on the PС keyboard constantly presses the left button, rewinding a high-quality test track for 5 seconds so that one and the same required segment sounds. The other hand switches the AB switch on the audio boxes. I have noticed that this method allows my ears to hear the difference in the sound of the devices. If I just listen to one track through one device, then this track through another device, then I don't notice the difference.
Before Arсam AVR10, I had an Yamaha RX-A1080, I compared the Yamaha and MCA 50 together. The sound through the MСA50 was a little louder, I did not notice the difference at the mids and high frequencies, but the lows were much better, faster and deeper. I was pleased with the purchase of the MCA50.
Today I compared Arсam and Anthem, and the result surprised me very much. The sound from Arсam sound much louder, the bass was more dynamic and snappier, I was struck by the fact that the trumpet on Arcam from the test track sounded close and completely open, while at Anthem I could barely hear it. Then I compared the total volume of all 5 channels thru Arcam with 5 channels thru MCA50. At high volume levels, Anthem sounded quieter by an average of 6 dB.
It is very strange and not entirely clear for me why this is so. I'm not an audio technology expert, I'm just an amateur who likes to compare things like that. I started using the Anthem MCA50 amplifier from the beginning of the year, before that it was in the warehouse of audio equipment new, not unpacked for several years. Maybe this is the reason for this difference.