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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
geoffkait's avatar
geoffkait
23,365 posts
 


stringreen
Marble is awful for a VPI.....it rings like a bell. DO try Bearpaws as I mentioned above. Roller bearings are no good for VPI...it must be anchored to the center of the Earth. Anything that allows motion doesn’t work. ..springs, Gingko balls, etc.

I have isolated many VPI turntables on my spring systems, including the new very heavy VPI Flagship turntable (on my new Super Stiff Springs), with great success. By the way, marble as the base under the component on a spring based iso system doesn’t ring. Anyone care to guess why not? The earth is not a stable platform, it is a springy one.
toddverrone's avatar
toddverrone
840 posts
 
Geoff, sorry, got my threads mixed up!
miner42 OP
709 posts
 
Listening room is on a second floor; suspended floor.  Main floor is a concrete slab.  I have done the dance thing around my TT and no problem with noise coming through speakers.  If I yell/scream into my cartridge I do hear a sound through the speakers.  As mentioned, I have now relocated my speakers to the adjacent walls and the REL to the adjacent wall, too.  REL is approx. 16.5' from TT; nearest speaker is 5' from TT.  I can play with monitor only with no issue but once I introduce the REL I need to turn gain down to reduce feedback as volume is increased.  Crossover is set at 49Hz on REL with 180° phase.
miner42 OP
709 posts
 
...and I did remove my KAB RF-1 filter and noticed the music is much more 'cleaner'; that filtered appeared to be adding noise to the music.  Downside is the woofer pumping is back during TT usage.  I will have to monitor the gain and find a happy medium.
raymonda
855 posts
 
Well, as I suggested early on, the best way to minimize your feedback problem was to relocate your table.

Whatever you do, don't put your table in the corner. That too can cause issues.

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