Beomaster 5000 type 2323 incessant hum between tracks, & prob connecting powered sub

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Michael Posted: Mon, Aug 20 2018 7:22 PM

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I have two issues and any help would be much appreciated and to give the full landscape of the system, I am using the following equipment elements:

• Beomaster 5000 (type 2323) with Master Ctl Pnl 5000, both represented as "tested by a professional" and seem to work fine.
• Speakers: early 90's Norman Lab Model 10's connected using the B&O specific 2 pole speaker plugs soldered onto sufficient ga speaker wire.
• Turntable: Techniques SL-1200 Mk 2 connected using RCA to round B&O specific multi pin plug adapter WITH a separate ground wire lead that is connected and being used as designed.
• Sub: Sunfire Model D-12 powered sub using line level signal from the 5000 and again using the B&O specific plugs soldered to heavy ga sub appropriate wire and worked well using my old B&O 3300 receiver.
• A couple of things of note are: 1) This receiver offered the option of plugging components in via the round multi pin that the B&O cables would have come with or RCA's to the same component ports which would imply that either would work fine, when in fact, the RCA connections didn't work well at all and just happen to have a few of those adapter cables that I must have used on my previous model B&O 3300 receiver. 2) While the line in signal to the B speakers on my 3300 receiver worked well with the Sunfire powered sub, it's not with the 5000 but there is a coax input available on the sub and wondered if that should be connected to the 5000 via "preamp out" port or something using another adapter cable?

The problem: with everything on and secure there is a significant hum coming from the speakers that increases with the volume elevation, and prior to droping the needle on the record as well as between songs then of course is masked when the song begins to play, unless I guess I was playing some softer classical or something and then would actually disrupt the quality B&O sound, which I guess it's doing anyway.

Q1: Anyone have any idea why this is happening and how I can address it?

Q2: (previously asked in the final bullet above) is there a proper way to make a non B&O powered sub, with the option of line level input or coax input, talk to the B&O in a proper way and compliment with those enhancing low frequencies?

Thx much and any input is much appreciated.

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Saint Beogrowler replied on Mon, Aug 20 2018 7:47 PM

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Why didn't the phono RCA inputs work for you, they should. I'd check your adapter.

I'm assuming it is only humming with the turntable and not the radio or other inputs.

I've had good luck using the preamp out RCA's with a sub.

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Dillen replied on Mon, Aug 20 2018 10:39 PM

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Check the solder joints of the RCA sockets - the circuitboard copper traces often break near the joints.
Check the turntable chassis ground connection to the Beomaster. Use the fingerscrew if in doubt.

Martin

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Michael replied on Tue, Aug 21 2018 5:34 AM

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I don't really know, and I can't really remember what the behavior was when I used them initially, but I just remember that it wasn't well. I could certainly try them again, i was just wondering if they'd been damaged or something so tried the alternative, but the hum isn't well either so I'll try again.

To be honest, I only use the receiver to play the turntable so haven't noticed if it's in the FM broadcast, but I will to to try to pinpoint.  I like the idea of using the pre-amp outputs for the sub and will try that.  Thanks so much!!

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Michael replied on Tue, Aug 21 2018 5:35 AM

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Ok, Martin, Thanks for your input.