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Thump noise on the lead in on warped LPs

Hello friends
I have a Mitchell Tecodeck, with a upgraded Garrot Bros P77 cartridge.
I have moved appartments, which means I can turn up the volume a bit, but not that much!!
I have had a bit of a promble, a lot of my mint LP,s were purchased with shwink plastic, and a lot comes with a slight warp(Which I guess is normal)
I have played all above with no prombles, but now seem to have a "Thump" on the lead in track, when the cartridge,arrive to the top, but when the cartridge drops down from a very slight warp, it makes a Thump??, untill, half way thought 1st track, where it settles down
Hopimg some can help
Regards
David
128x128daveyonthecoast
diggory
38 posts
 
As Stringreen says, the arm needs lifting at the pillar as either the rear of the cartridge is riding on the warp or the warp is catching your tonearm (you don't mention what tonearm you're using). A tapered tonearm like the SME IV/V series can be hit by a warp if the warp is bad enough or the tonearm is too low.
moonglum
619 posts
 
Hello Davey...
I agree the likeliest explanation is the cart could be "bottoming" on the warp.
Also agree tapered SMEs and warps do not mix well.

If you are using a technodec then chances are you are using a Technoarm(?) I'm not sure these come with ready VTA adjustment. (Perhaps owners will advise?)

If this be the case you have options :

1. Shim the arm at the base.
2. An easier, less stressful fix is if the Technodec uses a 5mm mat you could try a thinner one e.g. Ringmat with Latex underlay (4mm), bare Ringmat (3mm) or the 3mm Achromat?

Kind regards...

PS : You may have to increase the VTF after any of these moves.
daveyonthecoast's avatar
daveyonthecoast OP
40 posts
 
Dear Friends
Thanks for all the feed back
When I mention that I have moved house, I can have the volume up a bit, thats when I noticed the "thump", om slightey warp LPs, as it has been very hot and humid down here, I have reset VTA etc!!
I was thinking, maybe the cartridge(Garrot Bros new P770 approx 200 hours), before many years ago I was running a Well
Tempered labs clasic,at high volumes, but becaused a long time ago I fogot the MC carridge?
I/m not sure do you all think. may be a promblem with the cartridge(suspension)?
Regards
David
daveyonthecoast's avatar
daveyonthecoast OP
40 posts
 
Dear Friends
Thanks for all the feed back
When I mention that I have moved house, I can have the volume up a bit, thats when I noticed the "thump", om slightey warp LPs, as it has been very hot and humid down here, I have reset VTA etc!!
I was thinking, maybe the cartridge(Garrot Bros new P770 approx 200 hours), before many years ago I was running a Well
Tempered labs clasic,at high volumes, but becaused a long time ago I fogot the MC carridge?
I/m not sure do you all think. may be a promblem with the cartridge(suspension)?
Regards
David
Daveyonthecoast (Threads | Answers | This Thread)
jameswei
883 posts
 
It is possible for a cartridge suspension to fail spontaneously after some period of use.

I don't know much about the Garrot Bros P770, but have you looked to see if the cartridge sinks too close to the vinyl?

I assume you would notice if the cartridge body were actually hitting the record, but a faulty suspension could result in poor tracking ability and cause the thump you are hearing even without the cartridge hitting the vinyl.

Do you have another cartridge to try?
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