Livemusic: I finally see what you're getting at
Just saw flicks of the newest SPJ TT on the Asylum. Found this link: http://www.rmhawk.com/arcici/turntable3.htm
To my surprise Arcici is only about 25 miles from my house.
Hadn't realized that anyone had done (commercially) the spiked upper platter before.
More interested than ever. I already have the Teres motor, does anyone know how many pounds the teres bearing can support?
Mike
Just saw flicks of the newest SPJ TT on the Asylum. Found this link: http://www.rmhawk.com/arcici/turntable3.htm
To my surprise Arcici is only about 25 miles from my house.
Hadn't realized that anyone had done (commercially) the spiked upper platter before.
More interested than ever. I already have the Teres motor, does anyone know how many pounds the teres bearing can support?
Mike
POUNDS AND KILOS.
Hi Mike,
The Teres bearing should able to carry at least 80 LBS of top load.
The split platter idea was something I played with 15 years ago already and passed on to Tom Fletcher for him to try.
He was so impressed he included the idea into his subsequent models.
The spikes (3) I currently use are only 0.01 inch high and habe a conical shape with the same 0.01 inch diameter.
They are made out of ceramic (AlO2) material.
Cheers,
Hi Mike,
The Teres bearing should able to carry at least 80 LBS of top load.
The split platter idea was something I played with 15 years ago already and passed on to Tom Fletcher for him to try.
He was so impressed he included the idea into his subsequent models.
The spikes (3) I currently use are only 0.01 inch high and habe a conical shape with the same 0.01 inch diameter.
They are made out of ceramic (AlO2) material.
Cheers,
SPJ TT
Mike,
I'm deeply impressed by SPJ TTs graceful, elegant and attractive look since I saw it once - the only TT branch designed by woman.
Strange, I never read any review or even feedback: seems thise beautiful jelly-fish like TTs are surrounded by cold silence (men's shauvinism or unattainable price?).
Anyway, nice to realize we are going same direction as well regarded commercial branches. As I can see, the upper platter is bolted to the underlaying metal disc for better rigidity I guess.
Simple and elegant T-base looks like good match to the massive and well dumped platter- rigid first.
The only thing is puzzling me - elastic/semy-elastic belt. Wouldn't the pitch stability be compromized? Or, otherwise, the belt compliance should be very carefully selected to absorb enegry when the motor pole pulls the belt and to release it when the platter is overtaking the motor, with unbeliveable precise timing?
Cheers
Michael
Mike,
I'm deeply impressed by SPJ TTs graceful, elegant and attractive look since I saw it once - the only TT branch designed by woman.
Strange, I never read any review or even feedback: seems thise beautiful jelly-fish like TTs are surrounded by cold silence (men's shauvinism or unattainable price?).
Anyway, nice to realize we are going same direction as well regarded commercial branches. As I can see, the upper platter is bolted to the underlaying metal disc for better rigidity I guess.
Simple and elegant T-base looks like good match to the massive and well dumped platter- rigid first.
The only thing is puzzling me - elastic/semy-elastic belt. Wouldn't the pitch stability be compromized? Or, otherwise, the belt compliance should be very carefully selected to absorb enegry when the motor pole pulls the belt and to release it when the platter is overtaking the motor, with unbeliveable precise timing?
Cheers
Michael
Re: SPJ TT
livemusic said:Mike,
Strange, I never read any review or even feedback: seems thise beautiful jelly-fish like TTs are surrounded by cold silence (men's shauvinism or unattainable price?).
Somebody gave it a short review somewhere, don't remember but I remember reading a profile of Ms. Spj herself. Anyhow, a lot of European products (especially German) are pretty much ignored by the US Audio press.
The only thing is puzzling me - elastic/semy-elastic belt. Wouldn't the pitch stability be compromized?
Could it be that other belt materials can't start the 60lb weight of the platter? Or all speed stability that is needed is provided by the rotating mass below the center of gravity?
Mike
ANOTHER SECRET.
Hi,
With such high rotating mass the motor becomes insignificant in force since once attained correct rotational speed it can be run as an idler without slowing down speed.
This is what we did on the early Dais TT using a spindle shape that decoupled itself from the motor after a calculated number of turns.
It was perfected later on in the Mentor range where a much higher mass was used allowing for absolute stabilty of speed during 45 minutes of record play.
Cheers,
Hi,
With such high rotating mass the motor becomes insignificant in force since once attained correct rotational speed it can be run as an idler without slowing down speed.
This is what we did on the early Dais TT using a spindle shape that decoupled itself from the motor after a calculated number of turns.
It was perfected later on in the Mentor range where a much higher mass was used allowing for absolute stabilty of speed during 45 minutes of record play.
Cheers,
Cones between platter layers
Is there a way so that the two platter layers separated by 3 small cones be fixed so it doesn't come apart? Or the top layer relies on its weight to stay placed.
Come to think about it...the LP12 is a dual platter design. THe outer platter just rests comfortably ontop of the inner platter.
Don't know why I never thought of that before lol
Is there a way so that the two platter layers separated by 3 small cones be fixed so it doesn't come apart? Or the top layer relies on its weight to stay placed.
Come to think about it...the LP12 is a dual platter design. THe outer platter just rests comfortably ontop of the inner platter.
Don't know why I never thought of that before lol
Belt vs. platter
Hi all,
Quite interesting discussion on Teres owners forum. One guy reported HUGE improvement after replacement of standard Teres silk string with Transcriptor round rubber belt. He has undumped acrylic platter on his TT. Another forum member says he got superior result with high quality unstretching fishing line. This make me think it's all about motor vibration transmitted through the belt and than to the stylus. May be the belt/motor/platter natural frequencies somehow interfere. Hard to belive the massive platter is prone to pitch instability due to the belt elastic properties.
One more point in favor of splitted/dumped platter design.
Cheers
Michael
Hi all,
Quite interesting discussion on Teres owners forum. One guy reported HUGE improvement after replacement of standard Teres silk string with Transcriptor round rubber belt. He has undumped acrylic platter on his TT. Another forum member says he got superior result with high quality unstretching fishing line. This make me think it's all about motor vibration transmitted through the belt and than to the stylus. May be the belt/motor/platter natural frequencies somehow interfere. Hard to belive the massive platter is prone to pitch instability due to the belt elastic properties.
One more point in favor of splitted/dumped platter design.
Cheers
Michael
Microscopic spikes...
I've machined tiny parts in my day but those are very tiny. Are you sure you have the decimal point in the right place?
What is the advantage of this?
If I were to go this route, I would either thread the subplatter(bottom platter)and screw in the cones or counterbore the platter to locate them precisely. I would also machine a very small dimple in the matching location on the upper platter to locate the cones precisely so that both platters are concentric.
This top platter would have to be made from material strong enough so as not to deform since it would only be supported by 3 cones, don't you think?
I've machined tiny parts in my day but those are very tiny. Are you sure you have the decimal point in the right place?
What is the advantage of this?
If I were to go this route, I would either thread the subplatter(bottom platter)and screw in the cones or counterbore the platter to locate them precisely. I would also machine a very small dimple in the matching location on the upper platter to locate the cones precisely so that both platters are concentric.
This top platter would have to be made from material strong enough so as not to deform since it would only be supported by 3 cones, don't you think?
SMALL IS BEAUTIFUL?
Hi,
Yes,I know this sounds petite to you all.Actually these are cut off steel nail tips.
However the size is not critical at all.
Regarding the pointing direction of the cones between both layers I leave that open to your experimentation.
Look at the cones as diodes,pin down energy drains away,pin up they block.
The uneven number is based on the unipivot principle that the less confusion for vibration drain you create the better it is.
Let me tell you up front that the difference can be nothing short of amazing.
I don't feel like explaining CLD and mechanical diode principles once more,just know that it's worth it's salt.
For the cones to stay in place a counterbore is quite effective but think of something small like just a mm deep so the spike/cones edges aren't touching the wall of the bore.
The top platter can't just deform when resting on these spikes/cones,it should be stiff.
PVC,Metacrylate are all stiff enough.
Cheers,
Hi,
Yes,I know this sounds petite to you all.Actually these are cut off steel nail tips.
However the size is not critical at all.
Regarding the pointing direction of the cones between both layers I leave that open to your experimentation.
Look at the cones as diodes,pin down energy drains away,pin up they block.
The uneven number is based on the unipivot principle that the less confusion for vibration drain you create the better it is.
Let me tell you up front that the difference can be nothing short of amazing.
I don't feel like explaining CLD and mechanical diode principles once more,just know that it's worth it's salt.
For the cones to stay in place a counterbore is quite effective but think of something small like just a mm deep so the spike/cones edges aren't touching the wall of the bore.
The top platter can't just deform when resting on these spikes/cones,it should be stiff.
PVC,Metacrylate are all stiff enough.
Cheers,
CONES.
Hi,
Probably,I just gave the example as that was what we first used.
The ideal materials for the cones will depend on the platter materials you use.
Since in the case of the nails the top platter was made out of Zamac and the bottom part was steel it seemed like a good choice at the time.
Feel free to experiment keeping in mind not to introduce a vertically compliant element,no springiness in the cones.
Cheers,
Hi,
Probably,I just gave the example as that was what we first used.
The ideal materials for the cones will depend on the platter materials you use.
Since in the case of the nails the top platter was made out of Zamac and the bottom part was steel it seemed like a good choice at the time.
Feel free to experiment keeping in mind not to introduce a vertically compliant element,no springiness in the cones.
Cheers,
Cones between platter layers
I read that Brass is a great self damping material. But I suppose there is merit in having the smallest cones possible. I don't know how small brass cones get.
How about cones made of the same material as the bottom layer of the platter. Aluminum. At first I thought how neat it would be to just machine one solid layer with the cones built in. But I think my machinist would have a fit doing that. I don't know.
I'm still favoring a 1" to 1 1/2" thick Aluminum bottom layer to mount the bearing into. Then a top layer of black PVC of 1". Recently I've read about alot of tables using PVC in their platters. Some don't call it PVC but its the same material. The new RPM-4 I beleive uses a 4mm thick PVC layer ontop of the platter. I'm a bit confused. Pro-Ject RPM and NottingHam plus others simply just let the top 4mm to 10mm layer of carbon fiber or PVC simply lay intop of the bottom layers. They don't bolt, glue or place cones between the layers. Why don't they do that?
Damping the Aluminum layer would be more difficult if I were to simply place the PVC layer laying on top of the bottom Aluminum layer seperated by cones. Originally my thoughts were to screw the two layers together in effect sealing in the leadshot filled cavities of the ALuminum layer. Now with just the PVC layer laying ontop that can't be done. So how would I seal the leadshot into the Aluminum layer. fdegroove I remember you mentioning that a 2" thick Aluminum layer does not need to be further damped. LiveMusic stated that he wants to glue or bolt? sandwich the bottom Aluminum layer with two acrylic thin layers. I suppose that would "seal" in the leadshot.
I went ahead and joined the Teres Audio forum. Its quite differant and takes some getting used to with all those posts coming to me emial.
I read that Brass is a great self damping material. But I suppose there is merit in having the smallest cones possible. I don't know how small brass cones get.
How about cones made of the same material as the bottom layer of the platter. Aluminum. At first I thought how neat it would be to just machine one solid layer with the cones built in. But I think my machinist would have a fit doing that. I don't know.
I'm still favoring a 1" to 1 1/2" thick Aluminum bottom layer to mount the bearing into. Then a top layer of black PVC of 1". Recently I've read about alot of tables using PVC in their platters. Some don't call it PVC but its the same material. The new RPM-4 I beleive uses a 4mm thick PVC layer ontop of the platter. I'm a bit confused. Pro-Ject RPM and NottingHam plus others simply just let the top 4mm to 10mm layer of carbon fiber or PVC simply lay intop of the bottom layers. They don't bolt, glue or place cones between the layers. Why don't they do that?
Damping the Aluminum layer would be more difficult if I were to simply place the PVC layer laying on top of the bottom Aluminum layer seperated by cones. Originally my thoughts were to screw the two layers together in effect sealing in the leadshot filled cavities of the ALuminum layer. Now with just the PVC layer laying ontop that can't be done. So how would I seal the leadshot into the Aluminum layer. fdegroove I remember you mentioning that a 2" thick Aluminum layer does not need to be further damped. LiveMusic stated that he wants to glue or bolt? sandwich the bottom Aluminum layer with two acrylic thin layers. I suppose that would "seal" in the leadshot.
I went ahead and joined the Teres Audio forum. Its quite differant and takes some getting used to with all those posts coming to me emial.
Re: He would have a fit....
Regards
Michael
Not shure you can gain any advantage simply pressing the cones into undumped metal subplatter. The main goal is decoupling bearing/belt vibration from the upper platter. One have to absorb vibration somewhere in between. The cones cannot do it by itself.Vinyl-Addict said:
Regards
Michael
CONES.
Hi,
Michael,
And that's not what they're for anyway.
You can safely rely on the sheer mass of the platters to do that for you.
If your bearing is quiet enough it won't generate all that much noise by it self.
Noise generated from the motor will be damped out if:
a) you use some kind of elastomer as belt material,preferably round and seamless.
b) you isolate the motor unit from the plinth.
c) if you decide to use a silk belt,make it long enough and it will act like a).
d) most motors only get upset because of mains fluctutions and other pollution riding it.
Cheers,
Hi,
Michael,
And that's not what they're for anyway.
You can safely rely on the sheer mass of the platters to do that for you.
If your bearing is quiet enough it won't generate all that much noise by it self.
Noise generated from the motor will be damped out if:
a) you use some kind of elastomer as belt material,preferably round and seamless.
b) you isolate the motor unit from the plinth.
c) if you decide to use a silk belt,make it long enough and it will act like a).
d) most motors only get upset because of mains fluctutions and other pollution riding it.
Cheers,
Platter ideas
I'm starting to see that alot of these ideas are dependant on bearing and motor implentation. My plan is to buy and use the Teres battery powered outboard motor and the Teres inverted bearing. So wouldn't the use of these high quality low noise products eleviate the need for some of the radical solutions in the platter design?
What I don't understand is why do some turntables have the uper most layer just resting on the lower layers. For example, the NottingHam Interspace with Hyperspace Platter. Its a 4" tall platter with a 1/2" thick graphite layer just laying ontop. No bolts and no cones.
If I were to use small 2 or 3mm tall solid brass cones shouldn't they be pressed into the top PVC layer with points down? Then have matching dimples in the bottom Aluminum layer so prevent the top layer from sliding around? I know Livemusic mentioned that 2 cones point down and the 3rd points up?
I'm assuming that the Teres bearing comes with a record spindle? Am i right in this assumtion? I have a record clamp allready which I beleive is the JA MItchel. Its a pressure clamp. You turn the top knob and the inner clamp tightens onto the spindle. It doesn't screw on threads.
Also, without starting a new thread. I've been considering using the OL RB250 tonearm for this project. But after some recent research on the web I have discovered the Morch U-6 and the BlueNote U-3. Anyone familiar with these two unipivot tonearms?
I can get a really good deal on both these.
The tonearms that some of you has designed and crafted are facinating but I don't have the ability or resources to make the attempt.
I'm starting to see that alot of these ideas are dependant on bearing and motor implentation. My plan is to buy and use the Teres battery powered outboard motor and the Teres inverted bearing. So wouldn't the use of these high quality low noise products eleviate the need for some of the radical solutions in the platter design?
What I don't understand is why do some turntables have the uper most layer just resting on the lower layers. For example, the NottingHam Interspace with Hyperspace Platter. Its a 4" tall platter with a 1/2" thick graphite layer just laying ontop. No bolts and no cones.
If I were to use small 2 or 3mm tall solid brass cones shouldn't they be pressed into the top PVC layer with points down? Then have matching dimples in the bottom Aluminum layer so prevent the top layer from sliding around? I know Livemusic mentioned that 2 cones point down and the 3rd points up?
I'm assuming that the Teres bearing comes with a record spindle? Am i right in this assumtion? I have a record clamp allready which I beleive is the JA MItchel. Its a pressure clamp. You turn the top knob and the inner clamp tightens onto the spindle. It doesn't screw on threads.
Also, without starting a new thread. I've been considering using the OL RB250 tonearm for this project. But after some recent research on the web I have discovered the Morch U-6 and the BlueNote U-3. Anyone familiar with these two unipivot tonearms?
I can get a really good deal on both these.
The tonearms that some of you has designed and crafted are facinating but I don't have the ability or resources to make the attempt.
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