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I am sure that you have done this but just in case. Did you connect the ground? Also, I have a Bellari phono preamp that had a hum until I hooked it into a different surge suppressor from the TT as I have 2 of the same circuit. You could try this too.
Guy,What did you do about this mess?
"Does that make sense ???"No, not really. It's not the look that concerns me. I suspect it's the source of your hum, RFI or whatever. Maybe you could shorten it and try an aluminum foil shield like Bacobits suggested. I just saw this statement: "By the way, with my new set up, the PDR linear arm, I have no ground wire." Good grief. C'mon now Guy, you can't break the rules all the time and get away with it. You need to solder or somehow attach a ground wire to the arm. It might be easier to use a ground post and a set of RCAs like the VPI set-up I posted earlier. You just need to leave enough slack so the arm can travel across the record unencumbered. I'm guessing you could lower that coat hanger about a foot or more. Once you have a ground to the phono stage the hum might go away. If you still have some residual hum you could try an additional ground wire between the phono stage and (pre)amp, but that might not be necessary.
What Neobop said! You should have a ground wire unless the ground is built into the IC's of the TT like my old Thorens TD-145. With that being said, I would try a ground wire attached to the tone arm and your preamp and see if this fixes the problem. Guy, what Bellari do you have? If it is the VP-130 it could be the crappy walwart as there is a known problem with the DC power supply. Radio Shack sells a DC power supply wall wart that has filtering and can fix the problem if that is the cause. I have the Bellari 129 and it uses an ac walwart.The hum can also be due to appliances in your house. Try unplugging the AC, Refrigerator,etc and see if the hum goes away.
I've had at least 4 variants on this type of arm and have never ground it.....never had a hum.The 195 page thread from Diy Audio has dozens of builds on this type of arm, or a close clone....metal bearingsrolling on glass tubes.None have grounded the arm....http://www.diyaudio.com/forums/analogue-source/238027-diy-linear-tonearm.htmlThe arm that Guy has worked with no hum here with my AT13e cart on my P3, but my wires were shorter andare set back in a tube like this pic of the Cantus Opus 3I've also had luck with longer wires hung overhead, this pic is of another I built.....no humNot that grounding the arm wouldnt help in Guys set up.....just havnt needed it before.I hope you get this sorted Guy...
Guy, I would still tape a wire to the tone arm and ground it to the phono preamp just to see if it fixes the problem. It is something that will take 30 seconds.
Is this the same system you're using without hum with other sources?What else is hooked up to the same AC line? You could try unplugging everything except the phono system and see if it goes away.Reconnect the ground wire and connect another ground wire between the phono stage and amp. You can use an unpainted chassis screw on the amp. You need bare metal. If the hum goes away leave that wire on and disconnect the one from the arm and see what happens. Even though you have a dedicated line it could be going to a mains box with other lines? That could be the source of the hum. If nothing works after Halloween is past, call Ghostbusters.Final suggestion - move back to the old place. neo
What's this Majik Buss, a noise filter, a song by the Who? I don't know what it is, but AC filters are notorious for creating what they're supposed to prevent. You might want to try plugging only the components you're using, directly into the wall. "I tried a ground wire from the arm and the phono stage to the amplifier inside ground buss bar "Sounds like you made a ground loop. Did it get worse? You have to connect the ground wire from the arm to the ground lug on the phono stage like you tried before. Then run another wire from the same ground lug on the phono, to a ground somewhere on the amp you're using. Are you biamping?Here's how I see it. You're getting hum from one of two places, either AC hum or from your phono. It's unlikely you're getting both and if no other source hums, it's probably only your phono. BTW, no preamp? How do you control the volume?Sometimes you can get hum between a phono stage and a preamp or amp. It's possible that as many as 3 ground wires are needed to correct. The usual ground from arm to phono, another to preamp, then another to amp. This is hooked up like 1 continuous wire with a couple of stops along the way. A phono cartridge requires much more gain than other sources to amplify the signal to useable levels. That makes it susceptible to noise and especially magnetic interference. Is it possible those unshielded wires run close to the turntable motor or some transformer? Maybe you can move the wires around, or the phono and get it to stop.Finally, You already shortened the wires. They terminate in RCA plugs at the phono stage? Secure the wires to the crook in the coat hanger (short as possible) with a cable tie or plastic tie. Unplug the RCA jacks and twist the wires by turning the plugs. Cross your fingers for luck. neo
Unshielded phono wires from the cartridge to anywhere hanging in mid-air are going to hum!Frank Van Alstine
