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Feedback through turntable

My system consists of a McIntosh C2300 preamp, MC452 amp, MCD500 SACD player, VPI Aries 3D with Ortofon Cadenza MC cartridge, Manley ChinookSE phono stage, PS Audio P5, Sonus faber Cremona Auditor M speakers and REL B1 Sub bass system.  My issue is with turntable use only; SACD has no issues.  On my pre when volume is +55 (peak at 45watts) I start to get feedback through the turntable - a sort of low freq sound, back off volume and it goes away.  My Auditor M speaker is about 3 ft away and in front of turntable.  I do have a rumble filter (KAB) installed between preamp and phonostage to help with sub woofer pumping.  Due to room layout I cannot rearrange the setup/move turntable.  My turntable is on a 2.5" block of wood and that sits on 4 isolation blocks via spiked feet.  Any thoughts how I can eliminate this problem?  Harry Weisfeld with VPI states he has 4 15" woofers (JBL Everest) near his Prime Signature setup with no issues at all.  Why am I having this problem and how can I eliminate it?  Thank you in advance for all feedback.
miner42
ct0517's avatar
ct0517
2,041 posts
 
 I feel the problem is airborne.

not likely

have you performed the audiophile dance yet to vet placement ?

in order to give recommendations we need to know what your floor is and how it is supported.  Wood floor with wood suspended beams, concrete pad, etc....  can you give some detail. 

stringreen
...... and I can do back flips, and never get feedback from the turntable.

how 'bout posting a youtube showing this ?


lewm
13,809 posts
 
CT0517, I have no dog in this fight, which is to say I am only guessing that the problem IS airborne.  I certainly could be wrong, since my opinion is based only on the paragraph submitted by the OP.  But can you say why you think the problem IS NOT airborne, with such conviction?

Rotarius, There is no harm in trying the cover, I agree.  But in general, I would never run any turntable with its dust cover in place.  This is based on trying it both ways, over many decades and with several turntables. Could it help in this particular instance? Maybe.  Anyway, trying the cover would tell us much about what is going on; if the cover makes a difference (for better or worse), the problem probably IS airborne.
ct0517's avatar
ct0517
2,041 posts
 

lewm - "not likely" means to me; other reasons are more likely and need to be explored.

Until we have more info on his floor structure - its all guessing

*********************************

Audiophile Dance.

keep your turntable motor off.

mute system at low volume. put on a record and lower the stylus on to the still record’s groove.

unmute and start raising the volume level until it is at the high level for your listening habits.

Start to Dance. any dance. jump up and down. Arm waving is optional. Do you hear anything through the speakers ?

Dance around the table to determine if there is bad loading point. If all is quiet ..... that spot is ok.

oh...before finishing..... try yelling at your cartridge (Baritone and Soprano voices) loud to determine if anything comes out of the speakers.


raymonda
855 posts
 
I don't know why I assumed he had an integrated..........just run longer interconnects and keep your amp where it is.  

Having your turntable so close to the speaker is just not smart. Also, do not place your table in a corner after you move your system.

This is the best solution to your problem.
rotarius
431 posts
 
My tonearm is only 32" away from my speaker but slightly behind the baffle. There is no issue with feedback at all.  Airborne seems unlikely from my experience. 
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