Advice needed on strange feedback

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Hi all
Has any any experience/knowledge of the problem I have been getting please
When I play my turntable at normal levels through my system, I get a "pulsing" of the mid/base driver ...on one channel
The cone moves in and out as much as 5mm while playing.. almost as if the drive is knackered
Except when I swop arm leads into the phono ...the pulses change to the other side and the previous side is normal again
When I contacted the speaker maker it was suggested that there was probably a compliance problem with the cartridge?
I can possibly believe this ..but don't know what I should be looking at / for?
The arm is an Aro in an LP 12 and the cartridge is a Hana SH

Thanks for any thoughts
 
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You haven't provided any detail on the electronics, I am going to assume that your pre-amplifier is integral with the power amplifier and not some custom device installed in the LP-12. (i.e. the cartridge signals themselves and not a pre-amplified/equalized signal is present on your lead outs)

This is a very odd problem, but most likely points to a defective cartridge. Outside of my experience with MC where problems generally have been present on both channels or were a reflection of a problem elsewhere.

More detail about the rest of the system would be helpful. Do you have another cartridge you could try?

Is this phenomena level dependent or present at all playback volume levels. (If it is level independent it is not feedback at all.)
 
Cart feeds into a valve phono stage then into pre amp and then amp
Problem does get more noticeable as volume increases...but is not audible at any time
As stated ..it is confined to one channel and that is the cartridge left channel...ie the record inner groves
Adjusting the anti skate seems to slightly reduce the effect
It is not present on any other source component
 
Quite hard to estimate that!!
My guess is the driver is pulsing in and out at about 3 to 5 times a second
This is in addition to the normal movement due to the sound it is reproducing..as it still plays as normal
I have now replaced the driver as the manufacturer thought this must be a faulty driver...it was not...it is still doing it ...but slightly less... maybe due to the brand new driver being stiffer as not run in??
 
Does the Aro arm have some peculiar pivots? An arm has to move in all directions, so most arms have separate pivots for vertical and horizontal movement but there is no reason why two other orthogonal directions could not be used. An arm with two 45 degree pivots might give the results you have, if one pivot has significantly different damping from the other one.
 
Does the Aro arm have some peculiar pivots?

You probably don't know the Aro is a unipivot :p

I always feel a bit uneasy with the idea of combining a unipivot with a suspended table. Yes, it is done a lot and people seem to like it but it seems too many degrees of freedom and a separate resonance attached to each one...

Is the weird behavior in any way affected by tuning the Linn's suspension bounce?
 
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Can you swap tubes left to right on the phono stage. It's not unknown for a dying tube to exhibit some wierd issues and should be easy to test. Although it is more likely to be cartridge/arm/table, especially if antiskate adjustments change things.

Silly question, is the Hana a recent swap? I only ask because the linn cartridges have a different hole to stylus spacing than almost anything else. Other than that recheck azimuth , tracking weight and antiskate after checking the bearing is clean.
 
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