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Did the hum start with the arrival of the phono cart? Is your tube amp hum free? Mine isn't, but bearable after installing a bigger choke. Twist the wires so that you have a cancellation effect of RFI. I use twisted pair interconnects homemade from plenum rated Cat 5E and they are dead quiet.And the Bellari power supplies are known to be crap.
Hi Frank.I've connected my original Rega RB301 with it's ground wire connected to my Pro-Ject phono stage and I've put the arm resting on top of the turntable platter temporarily connected and even if the Rega arm was shielded I had the same hum, therefore the bare wires are not the problem.Guy 13
With the ground I did everything you mention above and no difference with the hum level.I don't know if my GR Research SA-1 ss sub woofer plate amplifier is consider as bi-amplification, but I also did un-plugged those too. Again, no difference. The hum is present in the Omega and the sub woofer, but with the sub-woofer disconnected, I get the hum in the Omega 7F.No pre-amp, my Decware SE84C+ is an Integrated and with my CD player the Decware is death quiet, even when you put your ear against the drivers.I've tried:Ground from arm to phono, phono to integrated amplifier and/or any combination you can think of.I also tried shutting off the turntable motor, even disconnecting it from the wall, no transformer near by.I have one last trial to do and that's to by pass the Majik Buss (No it's not a song...)then the last test I will do, is to replace the walwart with two batteries to have 18V (12V + 6V) of pure DC voltage.I will get back to you next week.I hope it will work, otherwise my vinyl rig will gather dust for a very long time.Guy 13
Do you get hum when you install shorting plugs into the phono inputs on your preamp?Have you tried substituting an inexpensive turntable arm cartridge into your system? Maybe borrow one from a frined.I know that some Rega turntables do hum with some Grado cartridges due to lack of electomagnetic shielding in both the TT motor and cartridge. Do you possibly have a similar issue?Frank Van Alstine
Not quite sure what this means. "and even if the Rega arm was shielded I had the same hum, therefore the bare wires are not the problem"Was the Rega tonearm interconnect to the phono preamp shielded or not? Was a cartridge hooked up? A phono cart is like a microphone with its amplification requirements. Ever see an unshielded microphone cable? They're shielded because the signal is a very low voltage and prone to pick up hum and RFI. PDR says no one ever had a hum problem with this ungrounded arm even if the wires were hanging in the air. I don't believe him. I suspect plenty of the builders had problems which they were able to work out. Some people run unshielded wires from their arm to phono pre and get away with it. Most of those people braid the wires to help reject hum and noise. Some of them can't work that out. Our previous moderator John TCG lived near a radio tower and was one of those people. First off, the Magic Bus is a song and the name is a play on words.So, you retried the ground scheme exactly as I described (not through the Majik and w/no multiple connections) and got the same results? That tells me the problem is somewhere in the record player or phono pre. "The hum is present in the Omega and the sub woofer, but with the sub-woofer disconnected, I get the hum in the Omega 7F.No pre-amp, my Decware SE84C+ is an Integrated and with my CD player the Decware is death quiet, even when you put your ear against the drivers."What makes you think this is 50Hz hum? Will the Omega play bass? Why does nothing else hum? I suspect it's plain old hum. Do you have the Phono Box USB output hooked up?Maybe it has something to do with your step down tranny and battery power will save the day, but it's unlikely. neo
PDR says no one ever had a hum problem with this ungrounded arm even if the wires were hanging in the air. I don't believe him. I suspect plenty of the builders had problems which they were able to work out. Some people run unshielded wires from their arm to phono pre and get away with it. Most of those people braid the wires to help reject hum and noise....
One last comment:Many of my LPs are 40 years + old, so I cannot expect the same quality as LPs bought recemtly.
guy 13,I have LPs from the '50's, '60's and newer. If you assemble a reasonably good system (you need not spend tens of thousands $$) you will definitely hear how great older LPs sound. I have some 78 rpm discs that will startle you how good they can be. A truthful system will also show you bad some new recorded LPs can be. SO fear not--hunt through the bargain bins, shop online, etc, etc. Old vinyl can be some of the best sound there is !Cheers,Mark
I’ve fix the problem myself, well, O.K. I guess I was lucky, but come on, give me a little credit here, I’ve worked so hard to find that simple problem, simple, now that I’ve found it and knows what it is.
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.
Good, glad it's fixed. Maybe we can lock this thread now.
