Hi,
Are the ground path of the Motor ( TT ) and the ground path of the tonearm separated ? I mean the ground of the motor and TT I would not bring to the Pre Phono but only to the ground of the main and only the ground of the TA to th apre phono ground connector.
Rgds
Adelmo
Are the ground path of the Motor ( TT ) and the ground path of the tonearm separated ? I mean the ground of the motor and TT I would not bring to the Pre Phono but only to the ground of the main and only the ground of the TA to th apre phono ground connector.
Rgds
Adelmo
I added a M3 bolt running through the carbon fiber and securing into the brass tube. from that bolt there's a small spade where the ground wire connects from the PIB and arm. Also connected to that spade is a second ground wire that is soldered to the tinned copper mesh that the wires travel through inside the arm's brass tube. The carbon tube has been sanded where the bolt and spade connect to it. I thought this would be enough, but I'm still getting a ground hum.
Thoughts?
Hi,
Sounds like the problem is more in the side of the TT and not in the TA. Any transformer near the TA or TAs wires? However I would try changing the material of the TA to see if hum still there. If it is might not be the carbon fibre wand. However I never used carbon fibre for my diy TAs, I like bamboo wand more.
Hope you get a solution soon.
Rgds
Adelmo
Even with the inexpensive Ortofon 2M Red moving magnet, this arm really performs. I use carbon fiber and mostly 3d printing because I don't have access to lathes or decent wood working. Oddly, we both just heard the DC motor warble on this highly modded WT Simplex table... not related to ground but certainly another issue to figure out.
Hi,
I would try to use copper braided mesh to isolate all the cable that goes and come to the motor of the TT and if possible also shield other related part since all the attempt to the TA have failed.
Rgds
Adelmo
The Cardas wires came twisted in pairs. Lary Pederson didn't twist both pairs together with his carbon arm, which I've emulated - each pair can be pulled individually forward or back. I'll make another arm and twist all together. I'm not absolutely sure how he grounded.
As it happens, the DC motor began warbling yesterday. I found an option recommended by an Amadeus owner and hope to tackle that soon as well. I'll do as you've suggested.
You can leave them in twisted pairs, just twist the two pairs together. The idea is to keep the ground wires as close together as possible, ie minimize the loop.
Here's the WT Simplex. I bought the plinth with no arm, platter, spindle - only the plinth, motor and the bearing. The distributor wouldn't sell me the platter with its attached spindle, so I used older Well Tempered parts and made a deeper base to accommodate the deeper bearing and spindle. I still have to possibly get a new motor and raise it 1/4" to be able to play 45rpm LP's. 3d printed many of the parts.
Just a thought - you don't have a phone base in the same room as the TT?
I had a hum & traced it to a phone base.
Even at the opposite end of the room I could move it around and change the volume (but never eliminate) the hum.
I had to put the master base in a different room and the slave base in the lounge.
I had a hum & traced it to a phone base.
Even at the opposite end of the room I could move it around and change the volume (but never eliminate) the hum.
I had to put the master base in a different room and the slave base in the lounge.
No phone base + wifi, bluetooth, yes - 15 feet away from the rack. On early attempts, I knew little about grounding. Know a bit more now obviously still not enough. I've incorporated a brass tube inside the carbon fiber tube and drilled through both to mount spade that has the ground coming from the PIB box, connecting tot he space with another wire going back into he arm and soldering to the tinned copper mesh that the signal wire travel through. The 4 signal wires are Cardas and came twisted in pairs. This last time, I kept the 2 pairs separate but in the same woven mesh. Would it be advisable to have the ground wire wrapped around the signal wires in the mesh, even with the ground soldered to the mesh? I haven't wrapped the wires too tightly out of the arm to the PIB. head shell is PLA plastic. The arm I'm emulating has a metal head shell. I'll try again and wrap the twisted pairs and ground more tightly as they exit the arm. Need to get a clog out of my 3d printer at present...
just thinking aloud here:-
1. Does it hum when the motor is not powered up?
2. Does it only hum when playing a record ie stylus on the vinyl?
3. If it hums when the motor is on, does the hum change according to the position of the arm over the platter?
1. Does it hum when the motor is not powered up?
2. Does it only hum when playing a record ie stylus on the vinyl?
3. If it hums when the motor is on, does the hum change according to the position of the arm over the platter?
You need to find if its electrical or magnetic.
Does it hum with psu unplugged and arm over platter, nothing spinning? If so it could be a gnd loop between source and phonostage. Super unlikely, but must be ruled out.
1.Take the belt off, unplug motor psu, spin the platter, hang arm over platter. Does it hum, if so it's magnetic. Eddy currents from platter. If not the platter is good.
2.Now put the belt back and do it again. Does it hum now, if so it's either eddy current or radiation from motor. If it's louder than in the previous case then it's magnetic, motor and platter.
3.Plug it in turn it on But dont play. Is it louder than before, if so it's the motor, electrical field or magnetic. If this is the only case that's noisy then it's just motor electrical noise.
4.Now play and hang the arm over the platter, is it louder than before?
Each requires a different fix. Which we can discuss, once you have results for every case.
No point speculating.
Does it hum with psu unplugged and arm over platter, nothing spinning? If so it could be a gnd loop between source and phonostage. Super unlikely, but must be ruled out.
1.Take the belt off, unplug motor psu, spin the platter, hang arm over platter. Does it hum, if so it's magnetic. Eddy currents from platter. If not the platter is good.
2.Now put the belt back and do it again. Does it hum now, if so it's either eddy current or radiation from motor. If it's louder than in the previous case then it's magnetic, motor and platter.
3.Plug it in turn it on But dont play. Is it louder than before, if so it's the motor, electrical field or magnetic. If this is the only case that's noisy then it's just motor electrical noise.
4.Now play and hang the arm over the platter, is it louder than before?
Each requires a different fix. Which we can discuss, once you have results for every case.
No point speculating.
Getting over a surprise COVID infection... I'll get back on the tonearm and table tomorrow and run through the suggestions. Motor is mounted on the other side of the platter. The last time I worked with it, the arm hummed when plugged into the phono stage and preamplifier whether resting on the arm rest or playing on vinyl. I put a few drops of Wire Glue on the inside inner bolt that runs thru both the Carbon fiber and Brass rods, in the event the connection of ground on the bolt was not sufficiently meeting the brass rod.
I really love the 2M Red for it’s sound, despite being a very entry level cartridge. My local audio shop runs one and it’s quite special, even in their big showroom rig.
This may have been answered, but is there a metal shielding tube carrying the wires inside the carbon tube? Is that metal tube grounded?
Check power supply, ground the transformer, if that is used.
If SMPS, 47 uF and 470 nF in parallel across rails may help absorb supply induced hum.
And see if there is over-gain on the amp, and whether amp ground is connected to TT ground, I had that happen to me once, the cheap RCA cable had open shields, changed to another after checking at the shop that it was really a coaxial cable and had ground continuity...cheap ones use zip cord.
If SMPS, 47 uF and 470 nF in parallel across rails may help absorb supply induced hum.
And see if there is over-gain on the amp, and whether amp ground is connected to TT ground, I had that happen to me once, the cheap RCA cable had open shields, changed to another after checking at the shop that it was really a coaxial cable and had ground continuity...cheap ones use zip cord.
Anyone got some tips on twisting Litz wires? No lathe here - the last time I twisted fine wires, I made a plus shape with popsicle sticks and drilled 5 holes, with one near the center and the other four at the ends and anchored the other wire ends. Rotating the plus by hand.