Basic turntable requirements and hum...Solved

[GCliff]

Hi,
My question is...Is there a good basic turntable on the market that I can buy that has all the basic technical requirements of being a good all-rounder? For example, good overall grounding, good interconnect cable to plug into the amp, hum-free motor or.. a motor that is at least is not creating excessive vibration through the whole turntable and good noise-free power supply.

I current own a Pro-Ject Debut 3 which I plug into a Naim Nait 3. Not sure how long I've had the TT but it must be more than five years. Recently I've noticed that the TT is creating a low hum, certainly it may have been there the whole time I've owned the TT from new. It's only noticeable during the quiet parts whilst playing a record.

I've looked at a lot of vid's on Youtube and I've done some testing of my own.... And discovered that the motor is vibrating like a 'good-un' which can be mitigated with some small sorborthane pads.
The shield (if there is one) in the interconnect cable isn't doing a very good job and the transformer supply is pretty noisey too.

It's possible for me to start sourcing cables and pads and do some basic soldering and buy a new power supply and the TT will be much improved but, what I'm curious about is.... Is there on the market currently, a good all-round TT (I'm not talking 'high-end' ) that gets all the basics right (electrically speaking)?

Thanks!
Garry

 

[sterling shoote]

Hi,
My question is...Is there a good basic turntable on the market that I can buy that has all the basic technical requirements of being a good all-rounder? For example, good overall grounding, good interconnect cable to plug into the amp, hum-free motor or.. a motor that is at least is not creating excessive vibration through the whole turntable and good noise-free power supply.

I current own a Pro-Ject Debut 3 which I plug into a Naim Nait 3. Not sure how long I've had the TT but it must be more than five years. Recently I've noticed that the TT is creating a low hum, certainly it may have been there the whole time I've owned the TT from new. It's only noticeable during the quiet parts whilst playing a record.

I've looked at a lot of vid's on Youtube and I've done some testing of my own.... And discovered that the motor is vibrating like a 'good-un' which can be mitigated with some small sorborthane pads.
The shield (if there is one) in the interconnect cable isn't doing a very good job and the transformer supply is pretty noisey too.

It's possible for me to start sourcing cables and pads and do some basic soldering and buy a new power supply and the TT will be much improved but, what I'm curious about is.... Is there on the market currently, a good all-round TT (I'm not talking 'high-end' ) that gets all the basics right (electrically speaking)?

Thanks!
Garry

I had 5 turntables before I found one which satisfied me, s Sony PS-4750, which I purchased 46 years ago. This direct drive manual TT fitted with a Shure V15 III cartridge seemed to deliver all that was in the groove to deliver, as well as show no sign of mistracking. Still, snap, crackle, and pop distracted from LP pleasures and sometime in the mid 80's I boxed up the TT to make room for a CD Player.

Now, interestingly enough, before abandoning the TT, I compared music from CD to the same music I had on LP to recognize that indeed the Sony/Shure system was tracking flawlessly. In other words, albeit for snap, crackle, and pop, the TT/Cart combination was on par to the CD Player experience.

At any rate, a few years ago I unboxed the old Sony and fired it up again to see if LP recording technology had advanced enough to deliver LPs free of defect and so far I do not think there's been any advancement other than software to digitize LPs and filter pops.

Nevertheless, I purchased a new turntable thinking I could improve the record playing process and outcome with a turntable having more adjustment features, to assure exacting performance, like adjustable feet, and vertical tracking angle adjustability, This lead me to buy a new Technics SL-1210GR, which as it has turned out sounds no better or worse than my Sony because each share all the qualities that are important for LP pleasure: accurate speed, quite motor, isolation from resonance, and high quality tonearm supporting exacting cartridge alignment.

Of all the basic turntables out there today with compelling feature sets like what I've come to appreciate, the direct drive models from audio-technica and Technics seem to stand out; plus, these models have s shaped tonearms and detachable headshells that make cartridge alignment fast and easy. So, if I was in your shoes, I'd check out the turntables from Technics and audio-technica.

 

[GCliff]

Hi Sterling Shoote,
Thanks for your prompt reply, I'll have a look at the models you've suggested .Cheers.

 

[highfigh]

Hi,
My question is...Is there a good basic turntable on the market that I can buy that has all the basic technical requirements of being a good all-rounder? For example, good overall grounding, good interconnect cable to plug into the amp, hum-free motor or.. a motor that is at least is not creating excessive vibration through the whole turntable and good noise-free power supply.

I current own a Pro-Ject Debut 3 which I plug into a Naim Nait 3. Not sure how long I've had the TT but it must be more than five years. Recently I've noticed that the TT is creating a low hum, certainly it may have been there the whole time I've owned the TT from new. It's only noticeable during the quiet parts whilst playing a record.

I've looked at a lot of vid's on Youtube and I've done some testing of my own.... And discovered that the motor is vibrating like a 'good-un' which can be mitigated with some small sorborthane pads.
The shield (if there is one) in the interconnect cable isn't doing a very good job and the transformer supply is pretty noisey too.

It's possible for me to start sourcing cables and pads and do some basic soldering and buy a new power supply and the TT will be much improved but, what I'm curious about is.... Is there on the market currently, a good all-round TT (I'm not talking 'high-end' ) that gets all the basics right (electrically speaking)?

Thanks!
Garry

You're over-thinking this- you already have a good turntable. There's really no "getting the grounding right" on a newer turntable- it either needs to be grounded or it doesn't and the ground doesn't normally change unless you have moved the system. The audio cable can be replaced, but you don't need anything expensive- some of the great turntables came with a generic audio cable that was sourced from some anonymous supplier and nobody ever complained until the madness began.

Make sure the ground screw is tight- is the turntable sitting closer to the left side of the Naim? That could be a source of the hum- lift it (without the stylus on an LP and move it farther from the Naim and if it becomes more quiet, the distance needs to increase. If that helps but doesn't eliminate the hum, turn the turntable 90 degrees- magnetic fields interact less if they're at right angles.

 

[TLS Guy]

Hi,
My question is...Is there a good basic turntable on the market that I can buy that has all the basic technical requirements of being a good all-rounder? For example, good overall grounding, good interconnect cable to plug into the amp, hum-free motor or.. a motor that is at least is not creating excessive vibration through the whole turntable and good noise-free power supply.

I current own a Pro-Ject Debut 3 which I plug into a Naim Nait 3. Not sure how long I've had the TT but it must be more than five years. Recently I've noticed that the TT is creating a low hum, certainly it may have been there the whole time I've owned the TT from new. It's only noticeable during the quiet parts whilst playing a record.

I've looked at a lot of vid's on Youtube and I've done some testing of my own.... And discovered that the motor is vibrating like a 'good-un' which can be mitigated with some small sorborthane pads.
The shield (if there is one) in the interconnect cable isn't doing a very good job and the transformer supply is pretty noisey too.

It's possible for me to start sourcing cables and pads and do some basic soldering and buy a new power supply and the TT will be much improved but, what I'm curious about is.... Is there on the market currently, a good all-round TT (I'm not talking 'high-end' ) that gets all the basics right (electrically speaking)?

Thanks!
Garry

I need to know more about this. So I need to ask you some questions for clarification.

Is there hum when the turntable is not turning?

Do you only hear the hum when the motor is turning?

Do you hear hum if you place the stylus in the groove with the turntable still?

Is the hum only present when playing a disc?

The point of these questions is to ascertain, if this hum is actually electrical hum, or motor vibration transmitted through the stylus.

Your description of "the motor vibrating like a good-un", leads me to suspect this is not hum from poor grounding, but mechanical, from a worn out motor bearing.

If that is the case I will have some recommendations for you.

You might out of curiosity want to take a look at my post of last night and see that well made turntables should not give trouble in five years, but should be going strong well past the half century mark. That is what good engineering is all about.

 

[GCliff]

Hi highfigh,
Thanks for your reply, it does indeed sit to the left of the Naim. I've tried your suggestions, but it doesn't seem to make a difference. If I unplug the TT transformer from the wall the hum remains, if I then disconnect the TT interconnect there is a very light hiss from the speakers when the volume is at the 12 o' clock position but the hum has gone.....Not sure what to make of that. Just poor shielding on the interconnect perhaps? Or poor shielding at the connection point under the TT. Thanks!

 

[highfigh]

Hi highfigh,
Thanks for your reply, it does indeed sit to the left of the Naim. I've tried your suggestions, but it doesn't seem to make a difference. If I unplug the TT transformer from the wall the hum remains, if I then disconnect the TT interconnect there is a very light hiss from the speakers when the volume is at the 12 o' clock position but the hum has gone.....Not sure what to make of that. Just poor shielding on the interconnect perhaps? Or poor shielding at the connection point under the TT. Thanks!

An un-terminated input jack results in more noise because it can act as an antenna for interference and because the input circuit is designed to be connected to some amount of resistance. If you were to connect a resistor of similar value across the + and - of the audio cable, you probably wouldn't hear any noise and in fact, if you can, I would recommend that you do that as one of the tests.

The reason hum is fairly common with turntables is that the output from a phono cartridge is extremely low and the input needs to boost it so much that some noise is inevitable, whether hum or hiss. No other input section provides as much gain.

Is it possible that you may not have noticed it before?

 

[GCliff]

Hi TLS Guy,

Thanks for your reply, some answers below..
I've so far discovered that as soon as I connect the TT up to my amp a light hum appears, when I plug in the transformer for the TT (it came with the TT) no extra hum is heard, so the tranny isn't making the problem worse.

If I simply place the stylus down on a record without it revolving, it's the same hum, the pitch doesn't change etc.

When the platter revolves the hum can only be heard between tracks and in the quiet parts of the music.

The motor, here's what I know, it's sitting within an O ring, when I press down on it or push it to one side, it doesn't make contact with the plinth, it's as I would expect (it's suspended nicely) When I twist the pulley wheel it feels like it might be overly tight, a bit like overly tightning a bike wheel bearing but it doesn't grind or make any noise. The motor itself does vibrate though and this does transfer to the sub-plinth but not it seems to the steel plinth.

So, because I'm unfamiliar with other TT motors, is the vibrating motor normal?
Is it just poor shielding on the interconnects, or poor shielding in the area where the interconnect, connects to the TT. Thanks!

 

[TLS Guy]

Hi TLS Guy,

Thanks for your reply, some answers below..
I've so far discovered that as soon as I connect the TT up to my amp a light hum appears, when I plug in the transformer for the TT (it came with the TT) no extra hum is heard, so the tranny isn't making the problem worse.

If I simply place the stylus down on a record without it revolving, it's the same hum, the pitch doesn't change etc.

When the platter revolves the hum can only be heard between tracks and in the quiet parts of the music.

The motor, here's what I know, it's sitting within an O ring, when I press down on it or push it to one side, it doesn't make contact with the plinth, it's as I would expect (it's suspended nicely) When I twist the pulley wheel it feels like it might be overly tight, a bit like overly tightning a bike wheel bearing but it doesn't grind or make any noise. The motor itself does vibrate though and this does transfer to the sub-plinth but not it seems to the steel plinth.

So, because I'm unfamiliar with other TT motors, is the vibrating motor normal?
Is it just poor shielding on the interconnects, or poor shielding in the area where the interconnect, connects to the TT. Thanks!

Well, first of all none of my four turntables have vibrating motors. However the designers seem to have isolated your motor from the platter.

I would personally have zero pleasure in owning a turntable like that, and for that reason alone I would place in the junk category.

Now you obviously have a grounding problem. Your turntable should have a grounding tag on it, and there should be a wire from that to the grounding tag on your receiver, preamp, or integrated amp, whatever it is you are using.

The connecting leads only take the ground from the cartridge. Generally the separate grounding lead grounds the metal parts of the arm and the turntable chassis.

So a turntable requires two grounds as above.

So please make sure your turntable is correctly grounded and then report back.

 

[highfigh]

Hi TLS Guy,

Thanks for your reply, some answers below..
I've so far discovered that as soon as I connect the TT up to my amp a light hum appears, when I plug in the transformer for the TT (it came with the TT) no extra hum is heard, so the tranny isn't making the problem worse.

If I simply place the stylus down on a record without it revolving, it's the same hum, the pitch doesn't change etc.

When the platter revolves the hum can only be heard between tracks and in the quiet parts of the music.

The motor, here's what I know, it's sitting within an O ring, when I press down on it or push it to one side, it doesn't make contact with the plinth, it's as I would expect (it's suspended nicely) When I twist the pulley wheel it feels like it might be overly tight, a bit like overly tightning a bike wheel bearing but it doesn't grind or make any noise. The motor itself does vibrate though and this does transfer to the sub-plinth but not it seems to the steel plinth.

So, because I'm unfamiliar with other TT motors, is the vibrating motor normal?
Is it just poor shielding on the interconnects, or poor shielding in the area where the interconnect, connects to the TT. Thanks!

Some ProJect turntables came with a motor that uses AC voltage, but a DC version was available IIRC. Look at the motor's power supply for the motor's voltage and type.

 

[GCliff]

Some ProJect turntables came with a motor that uses AC voltage, but a DC version was available IIRC. Look at the motor's power supply for the motor's voltage and type.

Hi,
It's a ProJect 'Synchronmotor M303 16v AC 2VA'
I've just had another thought, could there be a short in the motor?
I've recorded the hiss and the hum on my iPhone but unfortunately I can't find them within the folders of the phone when it's connected to the PC.

It's possible the hum has always been there but I've been listening to any buying more records recently and my ears may have just got sensitive to it.

 

[GCliff]

Well, first of all none of my four turntables have vibrating motors. However the designers seem to have isolated your motor from the platter.

I would personally have zero pleasure in owning a turntable like that, and for that reason alone I would place in the junk category.

Now you obviously have a grounding problem. Your turntable should have a grounding tag on it, and there should be a wire from that to the grounding tag on your receiver, preamp, or integrated amp, whatever it is you are using.

The connecting leads only take the ground from the cartridge. Generally the separate grounding lead grounds the metal parts of the arm and the turntable chassis.

So a turntable requires two grounds as above.

So please make sure your turntable is correctly grounded and then report back.

Hi,
Yes it's grounded, small lug next to the phono sockets. That's necessary otherwise the hum really gets loud.
Thanks.

 

[TLS Guy]

Hi,
Yes it's grounded, small lug next to the phono sockets. That's necessary otherwise the hum really gets loud.
Thanks.

So that narrows this down to two possibilities.

The first is that a ground has gone bad, and has increased resistance. The most likely place is at the cartridge. I would start by cleaning those contacts up.

Next you need to take your multimeter, and while the cartridge is disconnected check the resistance all the way through to your ground that connects to your RIAA input. It should should zero resistance. If it does not then you will have to check from ground to ground and check the bad one.

Now the metal part of your arm should be grounded and so check the resistance between the arm and your amp lug. That should also be zero. If it is not, again you will have to trace it though, which will mean some degree of dismantling of your turntable to gain access.

Lastly cartridges can cause this. The wires are tiny, and as cartridges age they can cause this. So a new cartridge could well cure this. I have seen this before.

One word of warning do not connect you multimeter across the cartridge terminals, that will ruin it.

Turntables electrically are very simple devices, and you should be able to trouble shoot this.

 

[GCliff]

So that narrows this down to two possibilities.

The first is that a ground has gone bad, and has increased resistance. The most likely place is at the cartridge. I would start by cleaning those contacts up.

Next you need to take your multimeter, and while the cartridge is disconnected check the resistance all the way through to your ground that connects to your RIAA input. It should should zero resistance. If it does not then you will have to check from ground to ground and check the bad one.

Now the metal part of your arm should be grounded and so check the resistance between the arm and your amp lug. That should also be zero. If it is not, again you will have to trace it though, which will mean some degree of dismantling of your turntable to gain access.

Lastly cartridges can cause this. The wires are tiny, and as cartridges age they can cause this. So a new cartridge could well cure this. I have seen this before.

One word of warning do not connect you multimeter across the cartridge terminals, that will ruin it.

Turntables electrically are very simple devices, and you should be able to trouble shoot this.

Hi, morning,
Thanks for this, so, some measurements...1st taken between the headshell terminals and all the way the RCA plug

White L+ 1ohm Blue LG 1.1ohms
Red R+ 2.5ohms Green RG 23.2ohms

2nd measurement taken between headshell and connection lugs under the TT

White L+ 0.8ohms Blue LG 0.8ohms
Red R+ 2.7ohms Green RG 20.6ohms

All read using the 200ohm scale. All cables disconnected from the headshell contacts. There are two ground cables, one at the head 0.7 ohms and one at the gimble end 3.7ohms, both soldered to the same lug.

Green RG seems excessively high?
Thanks. Garry

 

[GCliff]

So that narrows this down to two possibilities.

The first is that a ground has gone bad, and has increased resistance. The most likely place is at the cartridge. I would start by cleaning those contacts up.

Next you need to take your multimeter, and while the cartridge is disconnected check the resistance all the way through to your ground that connects to your RIAA input. It should should zero resistance. If it does not then you will have to check from ground to ground and check the bad one.

Now the metal part of your arm should be grounded and so check the resistance between the arm and your amp lug. That should also be zero. If it is not, again you will have to trace it though, which will mean some degree of dismantling of your turntable to gain access.

Lastly cartridges can cause this. The wires are tiny, and as cartridges age they can cause this. So a new cartridge could well cure this. I have seen this before.

One word of warning do not connect you multimeter across the cartridge terminals, that will ruin it.

Turntables electrically are very simple devices, and you should be able to trouble shoot this.

Hi, this is a second reply,

I've reattached the white, red and blue wires to the headshell and used some spare telephone wire to connect from the headshell all the way to the lug on the amp, guess what? Hum disappears! My next question is...Is it possible to replace the fine green wire/cable?

Thanks, Garry

 

[highfigh]

Hi,
It's a ProJect 'Synchronmotor M303 16v AC 2VA'
I've just had another thought, could there be a short in the motor?
I've recorded the hiss and the hum on my iPhone but unfortunately I can't find them within the folders of the phone when it's connected to the PC.

It's possible the hum has always been there but I've been listening to any buying more records recently and my ears may have just got sensitive to it.

A bad motor wouldn't cause hiss and it would either blow a fuse (it should be fused or able to interrupt the power, somehow) or fail to rotate/maintain correct speed.

If you're referring to the hiss, that's from the phono preamp. If the step-up is active, it's a noisy design or you're raising the level more than you did in the past- if you can check the Signal to Noise specs for the phono preamp and step-up (maybe you can, but their manual doesn't show it). If the S/N is less than about 67dB, you'll definitely hear it at higher levels, especially with a moving coil cartridge.

 

[highfigh]

Hi, this is a second reply,

I've reattached the white, red and blue wires to the headshell and used some spare telephone wire to connect from the headshell all the way to the lug on the amp, guess what? Hum disappears! My next question is...Is it possible to replace the fine green wire/cable?

Thanks, Garry

Yeah, 23 Ohms is far too high. How is the green wire connected?

 

[TLS Guy]

Hi, this is a second reply,

I've reattached the white, red and blue wires to the headshell and used some spare telephone wire to connect from the headshell all the way to the lug on the amp, guess what? Hum disappears! My next question is...Is it possible to replace the fine green wire/cable?

Thanks, Garry

So you have diagnosed the problem.

However we don't know that the problem is in the turntable wiring. So I'm afraid you will have to take the plunge and get inside the turntable. This could easily be a solder joint gone bad, especially in the era of lead free solder. So what you need to to now, is to check the whole grounding system point to point and find out where these high resistances are coming from.

Start at the head shell wiring and work your way back to identify the points of high resistance.

Only if the high resistance is between the head shell and the first termination will you have to replace the pickup arm wiring. This can be done, but I recommend you have a service manual to do this. If the pick up wiring is OK, then personally I would redo all the solder joints, as all your readings are high. I assume you have checked the ground connection in the cable with the RCA connectors that connects to the phono input.

It is tough guiding people through service work at a distance, but I will do my best.

I strongly suspect lead free solder as the root cause of all this.

 

[GCliff]

So you have diagnosed the problem.

However we don't know that the problem is in the turntable wiring. So I'm afraid you will have to take the plunge and get inside the turntable. This could easily be a solder joint gone bad, especially in the era of lead free solder. So what you need to to now, is to check the whole grounding system point to point and find out where these high resistances are coming from.

Start at the head shell wiring and work your way back to identify the points of high resistance.

Only if the high resistance is between the head shell and the first termination will you have to replace the pickup arm wiring. This can be done, but I recommend you have a service manual to do this. If the pick up wiring is OK, then personally I would redo all the solder joints, as all your readings are high. I assume you have checked the ground connection in the cable with the RCA connectors that connects to the phono input.

It is tough guiding people through service work at a distance, but I will do my best.

I strongly suspect lead free solder as the root cause of all this.

Hi,
I've measured the resistance between the tags underneath the TT to the RCA plugs,
White L 0.5 Blue LG 0.6
Red R 0.4 Green RG 0.8
So the main resistance is in the red/green right channel between the headshell and the tags underneath the TT.

I'm going to attempt to resolder the red/cables and see if the resistance reduces.

Thanks, I'll report back. Garry

 

[GCliff]

Hi,
I've measured the resistance between the tags underneath the TT to the RCA plugs,
White L 0.5 Blue LG 0.6
Red R 0.4 Green RG 0.8
So the main resistance is in the red/green right channel between the headshell and the tags underneath the TT.

I'm going to attempt to resolder the red/cables and see if the resistance reduces.

Thanks, I'll report back. Garry

Hi,
Thought I'd sum-up, I resoldered the red/green wires and the resistance dropped remarkably, especially the green.
After more tinkering about I decided to replace the RCA cable since I had some in my cable box....never throw cable out and that has done the trick, I keep checking it since I'm still not sure of the precise cause but I'm hum free! What a relief. Thank you for your time. Garry.