I have an old friend from High School who was gifted a nice new "audiophile" turntable and preamp for Christmas. He was all a-jitter on Facebook about it when he got it and yesterday he posted photos of it setup in his home stereo rig which consisted of a nice Teac integrated stereo amp, a basic disc player, and a pair of bookshelf speakers - all placed on the same console. He put the turntable between the left speaker and his amp / disc player stack and let go with some rocking tunes. But, he noticed he got a droning noise if he turned it up too loud.
I reached out and got him to call me... sure enough, he likes to play music loud enough to fill pretty much the entire downstairs of his house with music while he does stuff, all from the speakers in his living room.
I explained that the speakers were causing a feedback loop with the cartridge and he needed to either add isolation to the turntable, or move it onto a different surface which isn't connected to the one the speakers are on. He didn't believe me and was convinced his turntable was faulty.
I then suggested he try simply putting a full size folded up bath towel under each speaker and try again, and he said he could turn up the amp much higher with that setup. I recommended a pair of foam isolators for the speakers and some sorbothane feet for the turntable, or mounting the speakers on the wall so they were not on the same surface as the turntable. He said he'd look into it.
With digital audio we've forgotten how easy it can be to get feedback loops from our turntable setups. I remember nearly every receiver and preamp had a "rumble filter" switch which could was a steep high pass filter at about 25Hz which not only reduced rumble from LPs, but it also reduced feedback if you happened to have speakers which could actually output frequencies below 30Hz (something which wasn't all that common in home systems back in the LP's heyday). I haven't seen a rumble filter button or switch in decades, and I wonder if manufacturers just build them into every Phono preamp by default. Considering that most quality home systems these days have subwoofers which can produce substantial low frequency output, a rumble filter seems necessary most of the time.
Certainly, if the speakers are on the same surface as the turntable, this is a huge necessity and may not be enough.
I reached out and got him to call me... sure enough, he likes to play music loud enough to fill pretty much the entire downstairs of his house with music while he does stuff, all from the speakers in his living room.
I explained that the speakers were causing a feedback loop with the cartridge and he needed to either add isolation to the turntable, or move it onto a different surface which isn't connected to the one the speakers are on. He didn't believe me and was convinced his turntable was faulty.
I then suggested he try simply putting a full size folded up bath towel under each speaker and try again, and he said he could turn up the amp much higher with that setup. I recommended a pair of foam isolators for the speakers and some sorbothane feet for the turntable, or mounting the speakers on the wall so they were not on the same surface as the turntable. He said he'd look into it.
With digital audio we've forgotten how easy it can be to get feedback loops from our turntable setups. I remember nearly every receiver and preamp had a "rumble filter" switch which could was a steep high pass filter at about 25Hz which not only reduced rumble from LPs, but it also reduced feedback if you happened to have speakers which could actually output frequencies below 30Hz (something which wasn't all that common in home systems back in the LP's heyday). I haven't seen a rumble filter button or switch in decades, and I wonder if manufacturers just build them into every Phono preamp by default. Considering that most quality home systems these days have subwoofers which can produce substantial low frequency output, a rumble filter seems necessary most of the time.
Certainly, if the speakers are on the same surface as the turntable, this is a huge necessity and may not be enough.
