Question for the forum. This is something I’ve noticed—and wondered about—for a couple of decades: at very low listening levels, do amplifiers tend to favor one channel over the other?
When the volume is set just high enough to be barely audible, it often seems like either the left or right channel plays slightly louder. I’ve noticed this across dozens of different amplifiers over the years, which makes me wonder whether this is an actual characteristic of some gear, a hearing-related issue, or simply perception on my part. The sound always seems to balance out once the volume is increased slightly.
And feel free to be honest—don’t be afraid to tell me it’s just in my head, or the inevitable wisdom (and mileage) of aging ears.
Has anyone else experienced this, or can explain what might be going on?
At first thought I would attribute it to what Paul and team have worked so hard at, successfully, noise. I was shocked when I first used the phone app NIOSH and found the level of ambient noise in my “quiet” room. That noise would be symmetrical and even if it was, you room acoustics will muck with it. At high volumes of music that ambient noise is better much lost in the, well, noise. or said the other way around, a high enough level of noise and you won’t even hear the music. And compounding the simple acoustics, our brains use a huge amount of computing power to interpret sound. Noise makes that more difficult (speech understanding in a noisy environment). So back to PS Audio and the PMG series, it may seem pointless to have a S/N of 140 but the noise from all sources will compound. And given the effort that our brains exert to process sound, I would not be surprised if we focus on sources that are easier to process, making them seem louder.
Preamp channel matching? The only source I can point to is Schiit Audio reasoning for using 0.5 dB relay switched stepped attenuators in select preamps. That said I suspect it’s a combination of factors that you and JKWAustin pointed out.
I think there is more to the stepped attenuators. As an audiophile now for 65 years (with some time off for careers) who built his own equipment from kits, the classical potentiometer way back then was a nightmare. I am sure we all had a bottle of the cleaner (probably carbon tetrachloride) as the resistive surface and contact wiper were prone to accumulating junk that would make them sticky, have dead spots, and on and on. Surely technology has improved but it would be hard to beat the clean connection and longevity of a hermetically sealed, silver contact on/off relay. For a wake up on how the third world survives, watch a YouTube video of silver recovery from silver contacts. Good for them that silver is up to over $68/oz this morning, but talk about giving OSHA and EPA regulators heart attacks! Pouring gallons of concentrated nitric acid with gloves as the only protective gear and nitrogen oxides billowing skyward. To really put our contributions to air pollution in perspective, watch them recover carbon black and oil from used tires.
