Author Topic: qsxm3  (Read 20853 times)

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Offline peranders

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Re: qsxm3
« Reply #45 on: October 20, 2013, 06:03:49 PM »
If you use the MC mode the input signals are very small so you must separate input and output as much as you can.
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Offline yiancar

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Re: qsxm3
« Reply #46 on: October 20, 2013, 06:44:15 PM »
i have a mm stylus. how does one eliminate cap harmonics? so i can check if its that

Offline peranders

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Re: qsxm3
« Reply #47 on: October 20, 2013, 09:55:26 PM »
I can't really figure out your real problem. Do you have insulated phono terminals? You are using shielded wires? No antennas or loops?
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Offline yiancar

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Re: qsxm3
« Reply #48 on: October 21, 2013, 04:35:56 PM »
insulated rca, shielded wires and no loops or antenas ( not quite sure fir the antenas). maybe there is dc in my mains ? 

Offline peranders

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Re: qsxm3
« Reply #49 on: October 21, 2013, 06:04:14 PM »
Dead silent if the inputs are shorted?

DC in the mains will have no influence of the electrical hum, only mechanical.

Your case, connected to anything?

Antennas means wires that can pick up electrical or magnitcal fields.
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Offline yiancar

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Re: qsxm3
« Reply #50 on: October 21, 2013, 07:23:59 PM »
i have some unshielded wires for probing the power rails is there any chance to influende the hum?

Offline peranders

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Re: qsxm3
« Reply #51 on: October 21, 2013, 08:25:12 PM »
You can try to move them and see what happens.
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Offline yiancar

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Re: qsxm3
« Reply #52 on: October 24, 2013, 03:45:11 PM »
Cleaned up my wiring again and now am left with 50hz hum, any thoughts on that?

Offline peranders

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Re: qsxm3
« Reply #53 on: October 24, 2013, 06:17:41 PM »
The left channel isn't the same as the right when it comes to wiring. Try to identify the difference. If to hum is gone with shorted inputs then you know that the problem is before the inputs.
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Offline yiancar

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Re: qsxm3
« Reply #54 on: November 02, 2013, 02:50:07 PM »
lots of rewireing and a broken transformer later hum is 99% removed. now here is somethig crazy with my amp turned on, on full volume and the preamp off i get noise. turn the preamp on and yhe noise is still there. remove the rca which connects the preamp and the amp an the noise is gone. i tried lifting the earth connection on the preamp but no luck. i would like to point that what am hearing js noise and not hum.

any idea?

Offline peranders

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Re: qsxm3
« Reply #55 on: November 02, 2013, 07:41:46 PM »
Noise may come from high source impedance in your volume pot. Hard to tell.
/Per-Anders Sjöström, owner of this forum

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