Excessive hum from speakers

amplifiers, receivers and loudspeakers
speedknot
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Excessive hum from speakers

Post by speedknot » 18 Jan 2019 05:48

I just set up my new Fluance RT82 turntable. This thing is a work of art. I'm getting feedback on my speakers when played at higher volumes. It's hard to describe but its like a constant bass note. I grounded the turntable to the preamp and from the preamp to the chassis of the amp, as instructed in the turntable manual. The Parasound has a phono preamp. Any ideas as to what I'm missing here? See below for component list.


Parasound 2100
AudioSource Amp Three
Fluance RT82 w/Ortofon OM 10 Stylus
Klipsch R-820F

Spinner45
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Re: Excessive hum from speakers

Post by Spinner45 » 18 Jan 2019 06:30

You're likely getting feedback vibration from the speakers.
Proper placement and a solid table away from speakers is good common sesne.

speedknot
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Re: Excessive hum from speakers

Post by speedknot » 18 Jan 2019 06:43

Spinner45 wrote:
18 Jan 2019 06:30
You're likely getting feedback vibration from the speakers.
Proper placement and a solid table away from speakers is good common sesne.
The turntable is a good 6 feet away. Plenty distant from the speakers. The isolation feet on this turntable are incredible as well.

speedknot
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Re: Excessive hum from speakers

Post by speedknot » 18 Jan 2019 07:15

To be honest. It doesn't seem like a grounding hum. There's no hum when everything is on and the the music is playing at a low volume.

hobie1dog
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Re: Excessive hum from speakers

Post by hobie1dog » 18 Jan 2019 15:56

You may think your tt feet are superior in design, but so far what have told us sounds like a classic case for vibration reaching the tt. Set your tt on something that will totally isolate it from your equipment rack....like a pillow, inflatable pool toy, or even pick the tt up in the air when the rumble starts happening and see if it goes away. This exact scenario happened at my friends house and he thought his feet were of superior design as well. I had him pick up his tt when the rumble started and it went away, he then put Vibrapod feet under the tt and there was still noise when the volume increased, which I then had him remove the dust cover, and the problem was solved.

JoeE SP9
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Re: Excessive hum from speakers

Post by JoeE SP9 » 19 Jan 2019 00:32

Although my TT setup is relatively insensitive to vibration. I always remove the dust cover when playing vinyl.

jdjohn
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Re: Excessive hum from speakers

Post by jdjohn » 19 Jan 2019 01:34

+1 At least have the dustcover in the up position.

lenjack
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Re: Excessive hum from speakers

Post by lenjack » 19 Jan 2019 04:03

Always best to have the cover up when playing...better to have it off. Their new tables are supposed to have better isolation.

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Re: Excessive hum from speakers

Post by Spinner45 » 19 Jan 2019 04:47

lenjack wrote:
19 Jan 2019 04:03
Always best to have the cover up when playing...better to have it off. Their new tables are supposed to have better isolation.
Yeah, like advertizing a bridge for sale in china. :shock:

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Re: Excessive hum from speakers

Post by lenjack » 19 Jan 2019 04:52

Forgive me. I just noticed that you do have one of the newer models.

Sterling1
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Re: Excessive hum from speakers

Post by Sterling1 » 19 Jan 2019 16:59

OP, I suggest dust cover on and down. I'd also suggest evaluating bass emphasis, maybe to much. At any rate, I think your TT is picking up speaker output. You can confirm this by turning down the volume.

lenjack
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Re: Excessive hum from speakers

Post by lenjack » 19 Jan 2019 17:52

Dust cover will always pick up vibrations, and sometimes transfer them to the stylus. Cover down will transfer more vibrations. Cover up = less vibrations. Cover off = no vibrations.

Something else. If there is a static charge on the cover, it may reduce the tracking force, and cause mistracking. This has been well documented. :o :shock:

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Re: Excessive hum from speakers

Post by Sterling1 » 19 Jan 2019 18:33

lenjack wrote:
19 Jan 2019 17:52
Dust cover will always pick up vibrations, and sometimes transfer them to the stylus. Cover down will transfer more vibrations. Cover up = less vibrations. Cover off = no vibrations.

Something else. If there is a static charge on the cover, it may reduce the tracking force, and cause mistracking. This has been well documented. :o :shock:
The dust cover down = less vibration. The cover on prevents dust from being drawn to the spinning record's surface. And, the static charge on cover only comes while cleaning the cover, which has no effect on reducing tracking force since you are not going to clean the cover while playing a record unless you're just plain stupid. :D

JoeE SP9
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Re: Excessive hum from speakers

Post by JoeE SP9 » 19 Jan 2019 19:01

A TT dust cover up or down is nothing but a giant sympathetically resonating surface connected to the plinth. If the TT is not a suspended design it's an absolute certainty the vibrations a hinged dust cover picks up will be passed to the tonearm and platter.

In any case, even though my VPI HW-19 (main TT) is a suspended design I always completely remove the dust cover when playing any vinyl. With my Micro Sekai DQ-43 dust cover removal is an absolute must.

When the humidity level is very low I add a D-Stat mat in addition to always using a Zerostat. What with vacuum cleaning all my LP's and using a Discwasher or a Carbon fiber brush and an antistatic record cleaning arm, the dust cover on, off, up or down doesn't make much difference with my VPI. However, it makes an audible difference with my Micro Sekai TT.

Having the TT on a rack between the speakers places it in one of the most vibration prone spots in the room. As for me, all my gear is on a dual Flexy on the right wall adjacent to my chair.
Last edited by JoeE SP9 on 19 Jan 2019 19:42, edited 1 time in total.

Sterling1
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Re: Excessive hum from speakers

Post by Sterling1 » 19 Jan 2019 19:17

JoeE SP9 wrote:
19 Jan 2019 19:01
The dust cover up or down is nothing but a giant resonating surface connected to the plinth. If the TT is not a suspended design it's an absolute certainty some of those vibrations will be passed to the tonearm and platter. Even though my VPI is a suspended design I always remove the dust cover when playing any vinyl.

When the humidity level is low I add a D-Stat mat in addition to using a Zerostat. What with vacuum cleaning all my LP's using a Discwasher or a Carbon fiber brush and an antistatic record cleaning arm. The dust cover on, off up or down doesn't make much difference with my VPI (suspended design). However it makes an audible difference with my Micro Sekai DQ-43 DD TT.
What's an absolute certainty is without the dust cover on and down your spinning record is going to attract airborne dust. Tonight, turn off the lights in your listening room and use a flashlight to see your way to playing a record. Then watch the dust in the flashlight's bean being drawn to the record. If that dust does not create pops, no problem but if it does ya might want to rethink taking off the dust cover. I leave my dust cover on and down. It is not a giant resonating surface, nor is it a certainty that in this condition any vibration is passed to the tonearm and platter, unless I'm tapping my fingers on the dust cover to the beat of the music. :D

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