What are the best solutions to reduce Stylus Microphonics

[Bruce B]

In this case it is probably a combination of vibrations through the vinyl surface and vibrations in the cartridge body/headshell/arm. I can yell at my cart until I'm blue in the face and get zip. .

Well here you go. I placed the stylus on a record with out it spinning. I recorded the output of the phono and started talking (Gettysburg Address). The large spike is me saying nation about 1' from the stylus at about 85dB. Just to make sure my breath wasn't a factor, I spoke off axis. I'll say again... no turntable/arm/cart. is immune from noises in the air, especially if you play loud in the same room.

The first tracing is with the A/D converter at 6dB gain (where it normally is) and the second tracing is at 3dB gain. So if this is just my voice at roughly 400Hz, then just think what a good bass line would look like!!

 

[Bobvin]

But what happens Bruce, when the system is no longer static? I don't disagree that external vibrations must, to some degree, have an impact, but in a well isolated system under dynamic conditions what is happening at the needle vinyl interface would generally be of such greater magnitude as to make interference negligable. The drag of the needle in the groove also creates a system under tension, which would change the dynamics of the system as well. I don't think your static test indicates all that much compared to a dynamic system. That said, this is certainly one of the key aspects I imagine is considered in design of better tables/arms, and why isolation products are popular.

You might be able to replicate your experiment just hollering at a vacuum tube? I also imagine there is a frequency that, if replicated for a duration, would excite a tonearm to behave like Galloping Gertie, though one would not find such a frequency in normal playback.

 

[Bruce B]

But what happens Bruce, when the system is no longer static? I don't disagree that external vibrations must, to some degree, have an impact, but in a well isolated system under dynamic conditions what is happening at the needle vinyl interface would generally be of such greater magnitude as to make interference negligable. The drag of the needle in the groove also creates a system under tension, which would change the dynamics of the system as well. I don't think your static test indicates all that much compared to a dynamic system. That said, this is certainly one of the key aspects I imagine is considered in design of better tables/arms, and why isolation products are popular.
.

O'kay..... would it satisfy you if I conducted the same experiment in the silence between songs?

 

[Bobvin]

O'kay..... would it satisfy you if I conducted the same experiment in the silence between songs?

Hi Bruce, not sure if "satisfied" would be correct, I have no dog in this hunt—just trying to think analytically about your methods. I think my ClearAudio strobe disk has an area where one drops the stylus so there is needle drag when setting speed (using a 300hz strobe). Those grooves are smooth. Silence between tracks should work too. (I have a few LPs where intertrack silence is anything but, it makes me think my bearing is f'd up. Thankfully other records are dead quite between tracks.)

I am interested in your results. Thanks for doing the experiments. You could really geek-out and create a new method for analyzing turntables and isolation but there's a lot of variety out there—the many multiples of cartridge/tonearm/table combinations. Not to mention what frequencies have the biggest impact, something likely to change with each cartridge/arm/table.

Finally, the real question becomes, is the distortion noticeable while listening? Does it have any impact on ones enjoyment of the music? We know playback will never be perfect, and differing mediums have greater/lessor distortions. I can enjoy listening to digital, but prefer vinyl myself. Digital has its overly compressed, over-loud mastering that f's up a lot of current popular titles, and vinyl, well, the long list of complaints about vinyl have basis in fact for sure... and a lot of mental energy has been spent coming up with ways to overcome the flaws. I'm always amazed at how engineers approach solutions to these problems, and the degree to which they are effective. Good vinyl playback can be amazing, and just the pure simplicity of wiggling a coil of wire in a magnetic field to recreate the recorded signal, ******* brilliant!

 

[Atmasphere]

The platter pad is a variable that is poorly understood and often ignored. The best platter pads we have seen was made by Warren Gehl (now of ARC); he made them quite some time ago after an exhaustive study of existing platter pads, vibration in vinyl and numerous prototypes.

The final platter pad was so effective that it eclipsed many of the differences between turntables at the time- IOW any turntable that had it sounded better than one that did not. One interesting phenomena of his platter pad was that when you touched the stylus down on the rotating LP, there was significantly less 'stylus talk' audible from the stylus and LP itself (IOW with the volume turned all the way down). So the resonance of the LP and its tendency to talk back to the stylus is a very real factor and one poorly addressed to this day (Warren has not sold his platter pad in many years; the last one we got in sold for $1200 over 10 years ago...).

So if a person really wanted to address this issue the field is wide open; no-one and I mean no-one has an actual platter pad that is really all that effective. Warren's platter pad was a composite of a variety of materials. He never revealed what they were all about, but it did contain an aluminum disc to give it structural stability, lead dust to give it mass (which is no longer legal under EPA rules despite the fact that the dust is sealed within the composite material; nonetheless part of the reason he's not made any platter pads in years) and a thin Sorbathane pad on the bottom to interface with and damp the patter itself. The pad weighed about 4 pounds. The main body is an unknown amorphous material that he developed, which he did not say much about other than it has the same hardness as the vinyl in a typical LP so that vibration could be absorbed without reflection.

Mine is not for sale.

 

[DonH50]

Any airborne or mechanical vibrations at the stylus will be superimposed upon the output whether the stylus is moving or not. It is easy to check this by playing test tones into the system (e.g. using a mixer, something I suspect Bruce has around ) and monitoring the phono output. At one point ages ago I did a swept frequency test to see where my TT/cart was most susceptible and worked to better dampen the suspension etc. at those frequencies. By averaging the output (much harder ~30 years ago!) the test tones will readily pop out of the noise (when using a silent test track) or music (when playing a recording).

As an aside, one of the things I did was experiment with various platter pads to find those that best suppressed the coupling. IIRC I ended up with a stack of felt and rubbery foam and it still wasn't perfect. I agree with Atmasphere that this is an area ripe for experimentation and a better solution. My guess is the hype will far exceed the reality for most offerings... For the main suspension I ended up with big old mattress springs, about 6" or 7" tall, with the appropriate number and placement to optimize (minimize) coupling. I stuck foam into some of them to adjust the resonant frequencies, Looked like heck but worked great (I eventually made a little box to hide the springs).

 

[slowGEEZR]

The platter pad is a variable that is poorly understood and often ignored. The best platter pads we have seen was made by Warren Gehl (now of ARC); he made them quite some time ago after an exhaustive study of existing platter pads, vibration in vinyl and numerous prototypes.

The final platter pad was so effective that it eclipsed many of the differences between turntables at the time- IOW any turntable that had it sounded better than one that did not. One interesting phenomena of his platter pad was that when you touched the stylus down on the rotating LP, there was significantly less 'stylus talk' audible from the stylus and LP itself (IOW with the volume turned all the way down). So the resonance of the LP and its tendency to talk back to the stylus is a very real factor and one poorly addressed to this day (Warren has not sold his platter pad in many years; the last one we got in sold for $1200 over 10 years ago...).

So if a person really wanted to address this issue the field is wide open; no-one and I mean no-one has an actual platter pad that is really all that effective. Warren's platter pad was a composite of a variety of materials. He never revealed what they were all about, but it did contain an aluminum disc to give it structural stability, lead dust to give it mass (which is no longer legal under EPA rules despite the fact that the dust is sealed within the composite material; nonetheless part of the reason he's not made any platter pads in years) and a thin Sorbathane pad on the bottom to interface with and damp the patter itself. The pad weighed about 4 pounds. The main body is an unknown amorphous material that he developed, which he did not say much about other than it has the same hardness as the vinyl in a typical LP so that vibration could be absorbed without reflection.

Mine is not for sale.

Very interesting. I've not heard of that platter pad before. Mine was made by TTW and was a limited item (no longer made) and consists of steel, carbon fiber and cork. It weighs about four pounds and is also not for sale.

 

[Bobvin]

Anyone remember "Platter Matter" which was a pad with density and properties akin to human muscle? I had one of those for a long time in my early days in audio. Heavy rubbery substance... Can't speak to effectiveness as my early system speakers were not highly resolving.

 

[Atmasphere]

^^ Seems to me I had one of those a long time ago. Which reminds me:

We had a customer that had the idea that people hold instruments so the LP should be held by something fleshy as well. He settled on raw pigskin... He got it at the stockyards, cut it up and punched a hole in it for the center spindle, and then kept in a mayonnaise jar in the 'fridge when not in use until the flesh-eating bacteria got after it at which point he would go back to the stockyards and get more. Sheesh- you can't make this stuff up... anyway, after a while his LPs smelled like bacon, and finally the people at the stockyards found out what he was doing with the pigskin and they would have nothing to do with him after that. This really happened and I am not making it up.

 

[Loheswaran]

Hear a record through a Townshend with the trough fitted. It tidies up top end sibilance and makes the bass rock solid.

 

[Mike Lavigne]

2 points on this subject....

---active decoupling can reduce the affect of ambient noise on the stylus. it can sense and compensate for noise in the tt plinth and shelf (active shelves sense and compensate for noise from below and above). this is likely the major percentage of ambient noise effect on stylus microphonics. the armwand can still be affected to some degree but likely less so. I've seen the readout on the Herzan shelf show the noise from clapping my hands a foot from the tt that gets attenuated.

--moving a tt to another room can reduce ambient noise issues, but it adds the distance to cables and in an overall sense might reduce ultimate performance. a trade-off. and it makes casual listening a pain.

---I think that a record weight, clamp or vacuum hold down (or lack of any of those) will end up being a greater variable to stylus microphonics than a platter material or mat. the correct amount of damping to 'load' the pressing properly is critical. I guess the mat or platter material becomes part of the damping equation.

these are simply concepts I've come to believe as a result of observation and listening.

like other perspectives I have had over the years, i'm ready to hear why i'm wrong.

 

[Bobvin]

^^ Seems to me I had one of those a long time ago. Which reminds me:

We had a customer that had the idea that people hold instruments so the LP should be held by something fleshy as well. He settled on raw pigskin... He got it at the stockyards, cut it up and punched a hole in it for the center spindle, and then kept in a mayonnaise jar in the 'fridge when not in use until the flesh-eating bacteria got after it at which point he would go back to the stockyards and get more. Sheesh- you can't make this stuff up... anyway, after a while his LPs smelled like bacon, and finally the people at the stockyards found out what he was doing with the pigskin and they would have nothing to do with him after that. This really happened and I am not making it up.

LMAO! Mmmm, bacon!

 

[PeterA]

---active decoupling can reduce the affect of ambient noise on the stylus. it can sense and compensate for noise in the tt plinth and shelf (active shelves sense and compensate for noise from below and above). this is likely the major percentage of ambient noise effect on stylus microphonics. the armwand can still be affected to some degree but likely less so. I've seen the readout on the Herzan shelf show the noise from clapping my hands a foot from the tt that gets attenuated.

Mike, that is very interesting. When that pressure wave from your hands clapping reaches the cartridge and tonearm, how does the Herzan reduce that resonance? I mean, it has hit the cartridge and tonearm and the top plate sensor on the Herzan at basically the same instant. Once that pressure is already resonating inside the cartridge and tonearm, can the Herzan really eliminate it? I would think that pressure waves from the drivers are no different.

 

[DonH50]

It's not really "resonating" in the cartridge or arm. If it is I don't think there's anything you can do about it. IME/IMM (in my measurements ) most vibration is coupled mechanically (through the floor, bump the TT, etc.) or airborne (speakers, clapping hands, neighbors screaming, etc.) That sort of "noise" can be suppressed actively. A lot of test labs use active (anti-)vibration tables (my current lab does not but we had several at the last place I worked) plus they are used for fabricating and assembly some devices. As usual, there are trades... You don't want the active loop adding high-frequency noise by trying to follow every little wiggle, especially those beyond the loop's bandwidth, but do want to catch as much of the leading edge as possible to quickly damp any induced (coupled) noise.

Systems I have seen/used have pressure sensors (effectively little microphones) and/or accelerometers to sense coupled vibration.

 

[PeterA]

It's not really "resonating" in the cartridge or arm. If it is I don't think there's anything you can do about it. IME/IMM (in my measurements ) most vibration is coupled mechanically (through the floor, bump the TT, etc.) or airborne (speakers, clapping hands, neighbors screaming, etc.) That sort of "noise" can be suppressed actively. A lot of test labs use active (anti-)vibration tables (my current lab does not but we had several at the last place I worked) plus they are used for fabricating and assembly some devices. As usual, there are trades... You don't want the active loop adding high-frequency noise by trying to follow every little wiggle, especially those beyond the loop's bandwidth, but do want to catch as much of the leading edge as possible to quickly damp any induced (coupled) noise.

Systems I have seen/used have pressure sensors (effectively little microphones) and/or accelerometers to sense coupled vibration.

Don, if the plinth can pick up and be effected by the burst of pressure, or airborne vibration, from hand clapping or the speaker drivers to the extent that active isolation can respond as Mike described, is this same burst of pressure not also hitting the cartridge and tonearm? The plinth is much more massive than the cartridge and tonearm, and can therefore better deal with this airborne vibration than can something small and delicate. I don't understand how the active isolation can deal with that, if it indeed can.

One test could be to play an LP with no volume and see if the Herzan can pick up the vibrations from above or even the motion of the platter and bearing, especially in an unsuspended turntable like Mike's Wave Kinetics.

 

[Mike Lavigne]

Mike, that is very interesting. When that pressure wave from your hands clapping reaches the cartridge and tonearm, how does the Herzan reduce that resonance? I mean, it has hit the cartridge and tonearm and the top plate sensor on the Herzan at basically the same instant. Once that pressure is already resonating inside the cartridge and tonearm, can the Herzan really eliminate it? I would think that pressure waves from the drivers are no different.

the Herzan has 6 Piezoelectric sensors and 6 Piezoelectric actuators. they attenuate any sensed resonance by a certain amount. where you hear it's benefit is on musical peaks or in a system with high bass capability in very chesty voices or cellos/double basses. and you only hear the absence of distortion you previously assumed was on the recording. you hear greater delicacy and focus. I have a few pressings of chesty female vocals where I previously believed there was distortion in the grooves during the vocals that smoothed out with the Herzan and allowed me to grasp what it was doing (feedback was causing the distortion). once I picked up on that more things like that jumped out. there is nothing like distortion removed from a long term reference to grab your attention.

no doubt that ambient noise can affect a arm wand or stylus to some slight degree no matter how much you've attenuated that ambient noise effect in the rest of the system. if the bearing tower is no longer resonating (or resonating much less) my guess is that has more value in the equation than any specific ambient noise affect on the arm wand and stylus. the question is whether the affect on the arm wand and stylus is audible or not.

attenuate is a different thing than eliminate. what I think is that we are very sensitive to reduced distortion. is it reduced enough?

 

[PeterA]

the Herzan has 6 Piezoelectric sensors and 6 Piezoelectric actuators. they attenuate any sensed resonance by a certain amount. where you hear it's benefit is on musical peaks or in a system with high bass capability in very chesty voices or cellos/double basses. and you only hear the absence of distortion you previously assumed was on the recording. you hear greater delicacy and focus. I have a few pressings of chesty female vocals where I previously believed there was distortion in the grooves during the vocals that smoothed out with the Herzan and allowed me to grasp what it was doing (feedback was causing the distortion). once I picked up on that more things like that jumped out. there is nothing like distortion removed from a long term reference to grab your attention.

no doubt that ambient noise can affect a arm wand or stylus to some slight degree no matter how much you've attenuated that ambient noise effect in the rest of the system. if the bearing tower is no longer resonating (or resonating much less) my guess is that has more value in the equation than any specific ambient noise affect on the arm wand and stylus. the question is whether the affect on the arm wand and stylus is audible or not.

attenuate is a different thing than eliminate. what I think is that we are very sensitive to reduced distortion. is it reduced enough?

Yes, that all makes sense, but what I'm wondering is how can the Herzan reduce, eliminate or even effect an airborne vibration that is hitting your stylus an tonearm. I understand that the Herzan can sense a hand clap and respond. Can it detect the noise from a turntable bearing or the rotating platter? Can it pick up the motions in a cantilever?

Mike, have you tried to play an LP with the volume off and looked at the Herzan sensors to see if they register anything? How about lightly tapping on the headshell when the arm is at rest. Does the Herzan react? And if it does, how would it reduce or eliminate that vibration before it has already effected the cartridge?

 

[Mike Lavigne]

Yes, that all makes sense, but what I'm wondering is how can the Herzan reduce, eliminate or even effect an airborne vibration that is hitting your stylus an tonearm. I understand that the Herzan can sense a hand clap and respond. Can it detect the noise from a turntable bearing or the rotating platter? Can it pick up the motions in a cantilever?

the sensors sense resonance from below or above. but only thru it's own chassis. so anything sitting on top, or below, the chassis that has resonance will receive attenuation. if the turntable mechanicals (bearing, platter or motor) transfer resonance to the Herzan then there will be attenuation of that resonance input. if it's ambient noise from whatever source sensed that will be attenuated. the Herzan does not discriminate as to the source of the noise that I know of, and only the top plate gets the compensation from the actuators so the target gear gets the benefit.

I cannot see where the cantilever motions would be sensed by the Herzan as the cantilever's purpose in league with the arm wand and stylus is to be of itself and not transfer it's movements beyond that 'system'. you do not want any active system to modify the performance of the cantilever, as that would compromise performance of the phono cartridge. infact; i'd say that the Herzan exactly allows the cantilever to operate in the ideal environment. it's the ultimate solution for isolating cantilever motion.....which seems to me to be the goal we strive for.

Mike, have you tried to play an LP with the volume off and looked at the Herzan sensors to see if they register anything? How about lightly tapping on the headshell when the arm is at rest. Does the Herzan react? And if it does, how would it reduce or eliminate that vibration before it has already effected the cartridge?

I have both tapped on the plinth sitting on the Herzan, and tapped on the armwand with the tt sitting on the Herzan. I saw lots of noise attenuation tapping on the plinth, but very slight noise attenuation tapping on the armwand near the bearing. I have not tapped on the headshell or cartridge. tapping on a headshell would be many degrees greater noise than the real world of ambient noise might cause. so I don't see much practical benefit from that exercise.

 

[PeterA]

the sensors sense resonance from below or above. but only thru it's own chassis. so anything sitting on top, or below, the chassis that has resonance will receive attenuation. if the turntable mechanicals (bearing, platter or motor) transfer resonance to the Herzan then there will be attenuation of that resonance input. if it's ambient noise from whatever source sensed that will be attenuated. the Herzan does not discriminate as to the source of the noise that I know of, and only the top plate gets the compensation from the actuators so the target gear gets the benefit.

Thanks Mike. So the Herzan would sense noise from a bearing, platter or motor if it is of great enough magnitude. Have you seen the Herzan sensors acknowledge these sources of noise when your turntable platter is spinning? If so, the resonances are already in the turntable system because they originate within the turntable. How then does the Herzan attenuate that resonance or noise and remove it from within the turntable system?

I was not clear before enough before, but that was essentially my question regarding the cartridge and tonearm. But the bearing, motor and platter are closer to the topplate sensors of the Herzan and should be more easily detected.