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Grado Timbre series Opus3 and support.

M

mouser830

New Member
Was thrilled to set up my Opus3 cartridge I just received yesterday. My table is a Rotel RP-955 stock and pristine. Removed a Sumiko BP No2. My phono amp is a Rega fono mk5. The cartridge sounds fantastic other than the hum. I only read the reviews which were glowing about this cartridge. I should have read the forums. Had I read the forums I would not have purchased the cartridge. The hum happens with or without the motor on. The table has a motor on/off and 33/45 speed controls switches.
I reached out to Grado and was told I need to shield my motor and after explaining the above info was told other cartridges hum too. And it’s the motor. I explained it happens with the motor off. They said call my dealer. I could quote directly from the emails I got this morning. What can I say except Terrible customer support. Never Grado anything again.
 
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mouser830 said:
Was thrilled to set up my Opus3 cartridge I just received yesterday. My table is a Rotel RP-955 stock and pristine. Removed a Sumiko BP No2. My phono amp is a Rega fono mk5. The cartridge sounds fantastic other than the hum. I only read the reviews which were glowing about this cartridge. I should have read the forums. Had I read the forums I would not have purchased the cartridge. The hum happens with or without the motor on. The table has a motor on/off and 33/45 speed controls switches.
I reached out to Grado and was told I need to shield my motor and after explaining the above info was told other cartridges hum too. And it’s the motor. I explained it happens with the motor off. They said call my dealer. I could quote directly from the emails I got this morning. What can I say except Terrible customer support. Never Grado anything again.
Click to expand...
Sorry to hear you're having hum problems; I know how frustrating that can be. Grados are more subject to that than other cartridges, but your turntable has a DC motor, and various Grado hum databases over the years tend to find those work okay. Since you're getting hum with the motor off, maybe there are other components too near the turntable. I once got hum because my Linn preamp was on a shelf directly below the turntable; when I moved it off to the right on another shelf, the hum went away. I'll add that an Audio by Van Alstine preamp located directly below the turntable did not cause any hum, so components definitely differ in how they affect things.

I wish you luck. If you've already tried moving things away from the turntable and you're still getting hum, maybe someone else will have more useful ideas.
 
Having many tables and a few Grado carts I've not had any hum issues. I've heard the wood bodies are not as susceptible to this problem also.

I've had hum issues that were finally tracked down to a loose negative terminal on the RCA jack on a table though.

Hope you're able to get this resolved the wood body Grados are quite schveet.
 
I reinstalled my Sumiko and quiet as a mouse. The motor is DC and in the left front of the platter. With the Grado Opus3, when I swing the arm inwards the hum varies until the arm and cartridge are aligned with the motor (at 7 o’clock) pointing directly at the motor, the hum all but goes away at elevated listening levels. This is the case if the platter is spinning or the table on/off button is off. Unplug the table and all goes away. I am playing a ElKit TU-8600s with a restored passive Sony SB-300 switching device for input changes. The phono preamp is a Rega fono mk5. So now since after multiple emails to Grado (who continually tells me it’s my TT that’s the problem) I will be taking apart my TT and shielding the motor for EMI. I also have a new circuit board here to modify a Yaqin phono amp that is coming from England. So I will see if tubes will help in the chain. I doubt it. Since all of my other sources played thru the same Sony SB300 are dead quiet at full volume I know it’s nothing else in the chain.
 
mouser830 said:
I reinstalled my Sumiko and quiet as a mouse. The motor is DC and in the left front of the platter. With the Grado Opus3, when I swing the arm inwards the hum varies until the arm and cartridge are aligned with the motor (at 7 o’clock) pointing directly at the motor, the hum all but goes away at elevated listening levels. This is the case if the platter is spinning or the table on/off button is off. Unplug the table and all goes away. I am playing a ElKit TU-8600s with a restored passive Sony SB-300 switching device for input changes. The phono preamp is a Rega fono mk5. So now since after multiple emails to Grado (who continually tells me it’s my TT that’s the problem) I will be taking apart my TT and shielding the motor for EMI. I also have a new circuit board here to modify a Yaqin phono amp that is coming from England. So I will see if tubes will help in the chain. I doubt it. Since all of my other sources played thru the same Sony SB300 are dead quiet at full volume I know it’s nothing else in the chain.
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Hum is probably coming from the mains transformer if it is located inside the plinth. Better to try shielding the transformer.
 
There's no hum when the turntable's power cord is unplugged.

There is hum when the turntable's power cord is plugged in.

There is hum whether or not the power switch is "on" or "off", as long as the turntable's plugged in.

I took a quick peek at your turntable's schematic and if I'm reading it right, the turntable's power transformer is energized as long the power cord is plugged in. The on/off switch is after the power transformer's secondary.

I think the hum is coming from the turntable's mains transformer, not from the motor.

Next thing I would check is wire routing: The signal wires (L+R) from the turntable to preamp should never run parallel and near to any AC power cord. They should run as far apart as possible but if they have to cross, they should cross 90°. This minimizes AC induced hum into the signal wires.

Finally, if the turntable's power cord is unpolarized, I would reverse it in the outlet. Half of the transformer's secondary goes to ground, which might be bothering your Grado.

Hope this helps.
 
Thanks much guys this makes sense would love to find the schematic for my TT. I tried some copper tape around the motor and no change. I tried a ground wire from the wall outlet and touched the spindle and then motor shaft and tone arm and the ground on the phono amp all separately with no change so I am sure it’s EMI. Knowing this about the transformer it’s time to turn it over and pull it apart. Not sure what to insulate it with but a metal box would be ideal I think. Btw the power chord is polarized.
 
heyraz said:
There's no hum when the turntable's power cord is unplugged.

There is hum when the turntable's power cord is plugged in.

There is hum whether or not the power switch is "on" or "off", as long as the turntable's plugged in.
Click to expand...

It can also be a ground loop problem.

Not necessarily a fault of the cartridge.
 
flavio81 said:
It can also be a ground loop problem.

Not necessarily a fault of the cartridge.
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I think ground loop hum would occur with every cartridge, not just his Grado. In fact, the O.P. has stated that his Sumiko is "quiet as a mouse".

Shielding between the cartridge and transformer should help.
If it were me...
For shitz and giggles I would put the stylus guard on the Grado and then cover the cartridge with aluminum foil. If that helps, maybe a layer of foil between the platter and the platter mat would provide sufficient shielding.

Maybe you can get by with a "stupid simple" fix.
I'd try it...easy to do and nothing to lose.
 
mouser830 said:
Thanks much guys this makes sense would love to find the schematic for my TT. I tried some copper tape around the motor and no change. I tried a ground wire from the wall outlet and touched the spindle and then motor shaft and tone arm and the ground on the phono amp all separately with no change so I am sure it’s EMI. Knowing this about the transformer it’s time to turn it over and pull it apart. Not sure what to insulate it with but a metal box would be ideal I think. Btw the power chord is polarized.
Click to expand...
Copper tape wont help, it is EMF you needs steel round the transformer.
Chris
 
Mine is also direct drive - and DC to boot..! No hum and I really enjoy the Opus3, too. It looses some upper detail of others but makes up for that with warmth and great bass. I would look for hum somewhere in your connections first thing.. :)
 
Ilikevinyl said:
My Grado ME+ Mono cartridge hums just a bit but doesn't interfere with the music on my Technics SL-1650. My Opus3 doesn't hum on the Thorens TD-160. Hummed a tiny bit but when I purchased a Music Hall Cruise Control 2.0 speed control the Opus3 is silent!

Here's a Grado Hum Database:

https://docs.google.com/spreadsheets/d/1k_Wr5zx-hcJ0as6wub8wIqsMu2a67DyLhzE8grJp9mc/edit#gid=0
Click to expand...
With the Technics the hum (only some not all as some have different transformer) is just the transformer, either relocating it to an external box or getting a Kab external psu which is an upgrade also is a way of fixing the issue.
Cheers
Chris
 
cafe latte said:
With the Technics the hum (only some not all as some have different transformer) is just the transformer, either relocating it to an external box or getting a Kab external psu which is an upgrade also is a way of fixing the issue.
Cheers
Chris
Click to expand...
That's an upgrade to HK turntables, to have transformer external too.
 
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