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Old 19th Sep 2021, 9:39 pm   #1
jimbilton
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Default Linn LP12 / K9

I have a Linn LP12 with K9 moving magnet cartridge. The last time I used it, after playing about half of an LP, it abruptly fell silent. That was a few years ago, and I've never got around to investigating the fault other than checking connections to the amplifier. I'm assuming the fault lies with either the cartridge or the phono stage of the amplifier. How could I check the cartridge?
To test the amplifier - which does still work on all other inputs - could I connect a Garrard 3000 with ceramic cartridge, or is the output from that too high / too low for a moving magnet input stage?
It is likely that I'll be selling this LP12, but I need to know if the cartridge is functional so that I can advertise it accordingly.
Thank you for any assistance.
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Old 19th Sep 2021, 9:56 pm   #2
Mark_RR
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Default Re: Linn LP12 / K9

It seems highly unlikely that a cartridge would fail on both channels at the same time, so the phono stage is the likely culprit. I see no reason why you couldn’t connect the turntable to a line input on your amp to test its output. It will be very quiet and very tinny, but if you hear any sound it will confirm the cartridge has output.
The K9 is hardly a great cartridge - I think an LP12 deserves better. So, i doubt the presence of a working K9 will affect the value if the TT much. The main thing to do is confirm the arm wiring is intact.
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Old 19th Sep 2021, 10:00 pm   #3
jimbilton
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Default Re: Linn LP12 / K9

Thank you very much, Mark, I'll do that.
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Old 19th Sep 2021, 11:38 pm   #4
Analogue man
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Default Re: Linn LP12 / K9

Whatever you do don't test for continuity of the cartridge using a meter on the ohms range without adding a resistor of known value in the circuit. A resistor of say 10K ohms would be fine, test the resistor first so that you know it's true value and then put it in series with the cartridge and if you get any reading of 10K ohms or more you have a working cartridge. The reason for the resistor is that the battery in the meter is capable of burning out the windings of a cartridge if connected directly.
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Old 20th Sep 2021, 11:26 am   #5
Herald1360
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Default Re: Linn LP12 / K9

Interesting! What sort of current is needed to kill a cartridge?

DMMs typically kick out around a mA or two, though older analogue meters can be rather more enthusiastic!
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Old 20th Sep 2021, 9:01 pm   #6
jimbilton
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Default Re: Linn LP12 / K9

Thank you Analogue Man, thank you Herald1360.
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Old 21st Sep 2021, 11:13 pm   #7
jamesperrett
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Default Re: Linn LP12 / K9

The simplest check for the phono stage is to see if it buzzes when you touch the + input connection? Turn the volume well down when you do this because the buzz will be loud if the phono preamp is working properly.
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Old 25th Sep 2021, 7:08 pm   #8
PaulR
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Default Re: Linn LP12 / K9

What amplifier are you using? It isn't Linn as well by any chance?
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Old 3rd Oct 2021, 10:21 pm   #9
jimbilton
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Default Re: Linn LP12 / K9

PaulR - No, it is a Harman/ Kardon PM655 integrated amplifier.

I set about my investigations this evening. I started by trying jamesperrett's suggestion of touching the phono input ( thank you James ) and I did hear a buzzing sound. So I connected the Linn LP12 and - it works again! It must be more than four years since it fell silent mid lp, yet now it works. I'll have to check the arm leads for intermittent continuity I guess. But I listened to a 1960's Bert Kaempfert LP all the way through with no problem. I'd forgotten just how good vinyl can sound!
Thank you very much to all who answered my call for help.
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Old 4th Oct 2021, 8:50 am   #10
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Default Re: Linn LP12 / K9

I just wondered because some of the Linn pre-amps can be troublesome.
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