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Mo-fi Ultradeck owners - popping noise from speaker upon power off

Guys, I got a mo-if ultradeck with mastertracker cartridge and I have a problem that I cannot figure out. When I turn the power switch off, I get a loud pop through my speakers. If turn the volume down or switch to another channel, then obviously I do not hear it.

I got the player replaced with another new unit and the same thing. I have tried everything - that I can physically do, replace power cord, hook up power cord to a different outlet, using different phono preamp, etc.

Does anyone else experience this? My other Project Classic SB TT does not have this at all in the same system.

I have searched the whole internet and found one post on Stevehoffman forum about experiencing the same and that person did all sorts of experimentation to no avail.

https://forums.stevehoffman.tv/threads/popping-on-power-down.1000508/

A $2500 player should NOT have issues like this. Period.
dandaroy
elliottbnewcombjr
5,742 posts
 
this unit is for sequentially timed turn on/off of amps/components, with 30 second intervals. 

adcom ace-515

https://www.usahifi.com/sites/default/files/product/494/manuals/Adcom%20ACE-515%20AC%20Enchancer%20Manual.pdf

it may solve your problem, avoid need to turn volume down.

I have one I am not using, I could put it up for sale here if you want, for what I paid, $60. or you can find them on eBay, ... they seem to be asking more these days

if it doesn't solve your problem, you can send it back, full refund, you pay return shipping.
builder3
771 posts
 
Never noticed that with mine. Then again I always turn the volume down to a low level at the end of the record. Love the TT, my only complaint is the cheesy plastic bumpers that continually fall off the dustcover.
dandaroy's avatar
dandaroy OP
21 posts
 
Unfortunately, I have to let go of this TT. I believe I have another defect in my turntable for which I will not be able to keep the TT. When the platter rotates, the center spindle sways or wobbles from side to side as it turns suggesting that there is some eccentricity. I took the platter off and reseated it several times with no luck. The platter seems to spin without any wobble. It is shocking to me that a $2500 table passed this quality inspection at Mo-Fi. I do not want to spend $2500 and have to worry about a warped table what it might be doing to sound quality.

https://www.youtube.com/watch?v=cve86r1Jkyk
big_greg
6,704 posts
 
As others have noted, I had this issue with my VPI Classic 2.  VPI sent me a replacement capacitor for the motor (for free).  It was very easy to swap out and fixed the problem.
dweller's avatar
dweller
3,824 posts
 
Either a bad cap or sloppy engineering. My cheapo Sony 4k player does this, occasionally,  when resuming from pause. Hope it doesn't blow out my tweeters.
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