Hi all,
I recently built myself a new turntable. The contractor who rebuilt my house left a piece of acrylic, very nice buiding material. It is more or less a Scheu-analog clone. Sounds way better than the wooden DIY tt I had before. On the tt there are 2 arms. A modified SME3009 (bronze bearing, bronze base, silver wire) with a goldring 1042. The other arm is a Scheu classic tone-arm tube (EBAY) with a self arranged bronze base and anti scating with magnets (as in a morsiani design). Element is also Scheu analog. The Scheu arm and element sound marvelous, beter than the SME, but there is one problem. There is resonance in the arm. The funny thing is that it is only in the right channel. My horns and LaScala mid-bas keep on ticking and humming even in a silent groove. As soon as you lift the needle it is gone. You can feel the conus of the speakers moving all the time.
I did put some foam and some bluetack here and there, and I made the point of the bearing a bit less sharp, I changed the weight, the antiscating, it all helped a bit but not enough.
Anyone any suggestions ???
Ciao, Werner:
I recently built myself a new turntable. The contractor who rebuilt my house left a piece of acrylic, very nice buiding material. It is more or less a Scheu-analog clone. Sounds way better than the wooden DIY tt I had before. On the tt there are 2 arms. A modified SME3009 (bronze bearing, bronze base, silver wire) with a goldring 1042. The other arm is a Scheu classic tone-arm tube (EBAY) with a self arranged bronze base and anti scating with magnets (as in a morsiani design). Element is also Scheu analog. The Scheu arm and element sound marvelous, beter than the SME, but there is one problem. There is resonance in the arm. The funny thing is that it is only in the right channel. My horns and LaScala mid-bas keep on ticking and humming even in a silent groove. As soon as you lift the needle it is gone. You can feel the conus of the speakers moving all the time.
I did put some foam and some bluetack here and there, and I made the point of the bearing a bit less sharp, I changed the weight, the antiscating, it all helped a bit but not enough.
Anyone any suggestions ???
Ciao, Werner:
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Hi Werner,
I am very glad that the magnetic antiskating according to the Morsiani method you applied to your Scheu tonearm helps t o make the sound better,this is the confirmation of my priciples!My name is Carlo Morsiani,I am the inventor and manufacturer of tonearms.
You have a problem in your arm, defintely there is nobody better than the inventor to help you.
Audio-Kraut observes correctly than the arm resonance should be present on both channels,but he can not know what happens with very sensible unipivot arms with my antiskating method.
The wide movement of the woofer are caused by subsonic frequencies,and these should appear on both channels equally when the antiskating is correctly adjusted.
I suppose that the antiskating adjustment is not correct,in this case subsonic can be more present in one channel then in the other.
To adjust the anti skating you need an uncutted disc,as some disco-mix have one face not cutted.
This is not the best method ,but it is easy and gives good result,
the best is to use a dual trace oscilloscope and test disc with fixed frequency.
Without antiskating the arm goes quickly to the disc center,with antiskating the arm stays stopped ,in the case of wire and counterweight antiskating the compensation force is constant,and if you adjust the arm to stay stopped at the middle of the disc,if you put the arm at the end of the disc,the arm returns to the middle,this shows that the skating force is not constant across the disc,but the skating force diminishes toward the disc center,so the constant force antiskating devices are approximative .My magnetic antiskating allows the antiskating force adjusted to diminsh toward the disc center, so it is possible to have the stylus pressure balaced on the two sides of the groove from the beginning of the disc to the end,and this is not possible with other methods.
If the adjustemt can not give the same subsonic amount on both channels,I suggest to try another cartridge,with less compliance,and to see what happens.
The vinyl replay gives always subsonic frequency,reducing the arm mass or less compliant cartridges can not remove the problem ,what is needed is a good sub-sonic filter in the phono preamp,and very few preamplifiers have well designed subsonic filters.I hope this is helpful for you,do not hesitate to contact me,I wish that who employs my antiskating method could state that it gives better performance and there are not problems.
Best regards,
Carlo Morsiani
I am very glad that the magnetic antiskating according to the Morsiani method you applied to your Scheu tonearm helps t o make the sound better,this is the confirmation of my priciples!My name is Carlo Morsiani,I am the inventor and manufacturer of tonearms.
You have a problem in your arm, defintely there is nobody better than the inventor to help you.
Audio-Kraut observes correctly than the arm resonance should be present on both channels,but he can not know what happens with very sensible unipivot arms with my antiskating method.
The wide movement of the woofer are caused by subsonic frequencies,and these should appear on both channels equally when the antiskating is correctly adjusted.
I suppose that the antiskating adjustment is not correct,in this case subsonic can be more present in one channel then in the other.
To adjust the anti skating you need an uncutted disc,as some disco-mix have one face not cutted.
This is not the best method ,but it is easy and gives good result,
the best is to use a dual trace oscilloscope and test disc with fixed frequency.
Without antiskating the arm goes quickly to the disc center,with antiskating the arm stays stopped ,in the case of wire and counterweight antiskating the compensation force is constant,and if you adjust the arm to stay stopped at the middle of the disc,if you put the arm at the end of the disc,the arm returns to the middle,this shows that the skating force is not constant across the disc,but the skating force diminishes toward the disc center,so the constant force antiskating devices are approximative .My magnetic antiskating allows the antiskating force adjusted to diminsh toward the disc center, so it is possible to have the stylus pressure balaced on the two sides of the groove from the beginning of the disc to the end,and this is not possible with other methods.
If the adjustemt can not give the same subsonic amount on both channels,I suggest to try another cartridge,with less compliance,and to see what happens.
The vinyl replay gives always subsonic frequency,reducing the arm mass or less compliant cartridges can not remove the problem ,what is needed is a good sub-sonic filter in the phono preamp,and very few preamplifiers have well designed subsonic filters.I hope this is helpful for you,do not hesitate to contact me,I wish that who employs my antiskating method could state that it gives better performance and there are not problems.
Best regards,
Carlo Morsiani
tonearm resonance?
Hi Werner,
I forgot one thing in my previous answer,,you have Klipsh La scala loudspeakers,the woofers are inside,and you can not look at these.
You can not hear subsonic frequencies,you need to see the woofers,and what you see are slow movements of the cone forward and rearward.The subsonic frequencies cause very wide amplitude displacement of the cone .
When the speaker is OK ,you do not hear nothing,but when a speaker has the coil touching the magnetic circuit,you hear scratches.Connect to your amplifier a frequency generator at 20-30 Hz, you should hear the pure frequency in the sane speaker,and scratching from the damaged speaker.
In your case,the right speakers could be damaged.
This happens when too much power drives the speaker,the cone is forced to its travel end and the coil hits the magnet ,and the coil round shape is altered,this makes the coil rattling against magnet,when very low frequencies cause wide displacement.
To see the loudspeakers in the La scala enclosures ,there is a door in the bottom side of the enclosures,open these doors and you can see the woofers,and you will see that both speakers have subsonic frequency movements when you play vinyl,you hear one speaker rattling because is damaged.
The cure is the loudspeaker dismantling ,this is not an easy job,if you never made this previously.There are specialist repairmen.
If you want to try the servicing, I can suggest to you how to do,I repaired many speakers.
In any case I suggest to you to add a subsonic filter in your phono preamplifier,the filter has to cut 16 Hz at 12db for octave,this allow the dobule frequency of 32 hz not attenuated.
It is very rare to find frequenies below 40 Hz in vinyls.
This will not reduce the low frequencies heard ,instead you will hear more clean bass.The subsonic frequencies below 20 HZ cause Doppler distortion,all frequencies above are modulated by the lower frequency,and thsi is not desiderable.In the La scala the woofers go up to 400 Hz,without subsonic filter all this range is distorted.
Best regards,Carlo Morsiani.
Hi Werner,
I forgot one thing in my previous answer,,you have Klipsh La scala loudspeakers,the woofers are inside,and you can not look at these.
You can not hear subsonic frequencies,you need to see the woofers,and what you see are slow movements of the cone forward and rearward.The subsonic frequencies cause very wide amplitude displacement of the cone .
When the speaker is OK ,you do not hear nothing,but when a speaker has the coil touching the magnetic circuit,you hear scratches.Connect to your amplifier a frequency generator at 20-30 Hz, you should hear the pure frequency in the sane speaker,and scratching from the damaged speaker.
In your case,the right speakers could be damaged.
This happens when too much power drives the speaker,the cone is forced to its travel end and the coil hits the magnet ,and the coil round shape is altered,this makes the coil rattling against magnet,when very low frequencies cause wide displacement.
To see the loudspeakers in the La scala enclosures ,there is a door in the bottom side of the enclosures,open these doors and you can see the woofers,and you will see that both speakers have subsonic frequency movements when you play vinyl,you hear one speaker rattling because is damaged.
The cure is the loudspeaker dismantling ,this is not an easy job,if you never made this previously.There are specialist repairmen.
If you want to try the servicing, I can suggest to you how to do,I repaired many speakers.
In any case I suggest to you to add a subsonic filter in your phono preamplifier,the filter has to cut 16 Hz at 12db for octave,this allow the dobule frequency of 32 hz not attenuated.
It is very rare to find frequenies below 40 Hz in vinyls.
This will not reduce the low frequencies heard ,instead you will hear more clean bass.The subsonic frequencies below 20 HZ cause Doppler distortion,all frequencies above are modulated by the lower frequency,and thsi is not desiderable.In the La scala the woofers go up to 400 Hz,without subsonic filter all this range is distorted.
Best regards,Carlo Morsiani.
Hello Mr Carlo Morsiani,
Thank you for your reply to my 'problem'. Maybe indeed I should make more effort to get the anti-scating right. It is now adjusted in the way you discribed, using a record-track without grooves. The needle stays on the grooveless part. I guess I need to use my tube-osciloscoop to set the correct anti-scating. The arm and cartridge are made for each other, so I don't see problems there.
My woofers are in fact only part of the klips LaScala, just the bas-part. They are DIY so I know the way to the driver. The ratle of the right LaScala was caused by the screws that keep the driver in place that were not tight enough.
The LaScala's just do the mid-bas. Real bas comes from an under-floor bas horn that goes to 28 Hz. Mids and high come from DIY wooden ORIS 200 horns with AER drivers. If you put the volume up you can very well feel the strong magnet pulling the conus of the right AER move foreward and back 'playing' a silent groove.
The also DIY tube phono-stage might indeed need a filter keeping the subsonic parts out of the signal. Thank you again for your reaction
regards,
Werner
Thank you for your reply to my 'problem'. Maybe indeed I should make more effort to get the anti-scating right. It is now adjusted in the way you discribed, using a record-track without grooves. The needle stays on the grooveless part. I guess I need to use my tube-osciloscoop to set the correct anti-scating. The arm and cartridge are made for each other, so I don't see problems there.
My woofers are in fact only part of the klips LaScala, just the bas-part. They are DIY so I know the way to the driver. The ratle of the right LaScala was caused by the screws that keep the driver in place that were not tight enough.
The LaScala's just do the mid-bas. Real bas comes from an under-floor bas horn that goes to 28 Hz. Mids and high come from DIY wooden ORIS 200 horns with AER drivers. If you put the volume up you can very well feel the strong magnet pulling the conus of the right AER move foreward and back 'playing' a silent groove.
The also DIY tube phono-stage might indeed need a filter keeping the subsonic parts out of the signal. Thank you again for your reaction
regards,
Werner
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