That Grado Opus3 Cartridge

[CrSens]

That is very strange, an unshielded low output coil should not pick up more hum than a bigger coil. I wonder of thee is more shielding paint on the high there is no other reason I can think of.
Chris

They are both from a production using shielding paint.. I was surprised also. Most likely the drop in hum pick up by the smaller coil is less than the big drop in generator output because of less turns in coil, so the hum pick up is more exposed (less masked by generator output).

 

[heyraz]

I think if both versions of this cartridge receive (like an antenna) the same amount of radiation (hum) from the motor (assuming the "broadcast" level from the motor is constant...which it should be regardless of cartridge), then any perceived difference between both versions of the cartridge are attributable to gain.

If the low output version of the cartridge requires more gain, then "hum" will be amplified accordingly.

 

[muovimies]

Could it be there's a ground loop component to the hum? Afaik regas are grounded through signal ground of one channel. Could result in ground loop hum in some systems and since it would be independent of the cartridge generator, it would become louder relative to signal with lower output cartridge.

 

[CrSens]

Could it be there's a ground loop component to the hum? Afaik regas are grounded through signal ground of one channel. Could result in ground loop hum in some systems and since it would be independent of the cartridge generator, it would become louder relative to signal with lower output cartridge.

Not in this case, the hum gets louder as cartridge is getting closer to the motor. It is loudest at the end of the record side.

 

[MisterDK]

Not in this case, the hum gets louder as cartridge is getting closer to the motor. It is loudest at the end of the record side.

Part of that Grado mystique… There’s long been a database of what they hum on. I figured the O3 wouldn’t hum on any of my tables, and it hasn’t on the first I’ve tried it on. It my or not matter but my Sony 2251 was Sony’s first direct drive and uses what’s supposedly an AC motor. Anyway NO hum, and possibly thanks to the chunky, wooden body, no dance..

 

[CrSens]

Part of that Grado mystique… There’s long been a database of what they hum on. I figured the O3 wouldn’t hum on any of my tables, and it hasn’t on the first I’ve tried it on. It my or not matter but my Sony 2251 was Sony’s first direct drive and uses what’s supposedly an AC motor. Anyway NO hum, and possibly thanks to the chunky, wooden body, no dance..

I've seen the database, it's somewhat anecdotal, it is what the owners report, so for some turntables you might nave both yes and no answers. It also depends heavily on how you listen for it, if you listen for it with stylus not in the groove but up, it is more audible and that turntable becomes the yes group, if you listen with the groove noise, it is masked and than it goes in the no group. The same turntable.

 

[muovimies]

Not in this case, the hum gets louder as cartridge is getting closer to the motor. It is loudest at the end of the record side.

My line of thinking was if there's also a ground loop component present, those two could add up, so that you'd get the same amount of induced hum, but with the low output cartridge the added hum from the ground loop would make it seem louder. Probably a bit far fetched In that case it would of course hum some even far away from the motor, or probably even the motor turned off.

 

[warrjon]

I have Rega P6 and both high and low output wood bodies. There is a huge difference in hum, low output is basically unusable without Humbucker, on high output hum is mostly hidden by vinyl noise (it is audible if needle is up in the air). On low outputs the proportion of stylus induced signal and hum interference is less favorable, the hum is less masked by the output.

My low output Opus 3 is in the MC at 64dB gain and at full volume there is zero hum, and the Opus 3 is on a linear tracker with open wiring from the carriage to bridge so noise puckup can be an issue.

It took a fair bit of fiddling of the ground topology inside the phono-preamp to totally remove the hum. I ended up having to star ground everything including the chassis/mains and ground post to the RCA shield.

My suggestion is to experiment with grounding until you have no hum.

 

[cafe latte]

My low output Opus 3 is in the MC at 64dB gain and at full volume there is zero hum, and the Opus 3 is on a linear tracker with open wiring from the carriage to bridge so noise puckup can be an issue.

It took a fair bit of fiddling of the ground topology inside the phono-preamp to totally remove the hum. I ended up having to star ground everything including the chassis/mains and ground post to the RCA shield.

My suggestion is to experiment with grounding until you have no hum.

Rega tables dont have shielded motors so unshielded carts like Decca and Grado will hum. There is no issues on most tables.
Chris

 

[MisterDK]

Kind of funny as my wife rarely comments on audio gear I pick up - but when I told her how nice I think the O3 sounds, all she could say is that it looks like “an ugly block of wood”… Made me laugh..

 

[MisterDK]

Time for an update about my HO Opus3. - Been using it since mid July this year.

I have 75 hours on it now, so it’s broken in enough and sounding unexpectedly good! With these hours now on it, upper-end detail is crisp and clean, not sounding rolled off. Bass is still quick and strong with no mush or flabbiness. Mids are sweet and smooth. Tracking @ 1.8g is good, though it’s probably not the very best tracker I’ve had. I do have it set up with very light anti-skating, BTW.

After four month of use, I like my O3 quite a bit. If I were shopping for a new cartridge in the 300- price range, I would pick up another. When the tip is worn out on this one, I could either trade in to Grado for a discounted new one - OR - send to a re-tipper for a much nicer tip. Re-tipping will cost more but would also make the Opus3 something truly amazing, I think….

 

[Sgt Shultz]

Time for an update about my HO Opus3. - Been using it since mid July this year.

I have 75 hours on it now, so it’s broken in enough and sounding unexpectedly good! With these hours now on it, upper-end detail is crisp and clean, not sounding rolled off. Bass is still quick and strong with no mush or flabbiness. Mids are sweet and smooth. Tracking @ 1.8g is good, though it’s probably not the very best tracker I’ve had. I do have it set up with very light anti-skating, BTW.

After four month of use, I like my O3 quite a bit. If I were shopping for a new cartridge in the 300- price range, I would pick up another. When the tip is worn out on this one, I could either trade in to Grado for a discounted new one - OR - send to a re-tipper for a much nicer tip. Re-tipping will cost more but would also make the Opus3 something truly amazing, I think….