Metal Plinth makers?

[13th Duke of Wymbourne]

Hi Thomas, FYI my musings are purely rhetorical. I am not looking for any one to try and answer or counter them them but to promote thinking outside the Linn box. I am not being critical of Linn. I do expect that all their products are a combination of a priori theorizing and design of experiment listening and their track record doesn't have to be proven to me. I greatly enjoy my LP12.

I will draw a line under my plinth/suspension musings to save us both a lot of time except for motor mounting. My interest is that I've had Lingo 1 since its release but I really cannot justify the cost of going to Radikal. Lingo 4 is reportedly better than Lingo 1. If we assume that any improvement is due to reduced vibration I wonder where the improvement comes from because the Lingo1 110V AC motor and Lingo4 12V AC are from the same family, just wound differently. They will consume the same amount of power and share the same bearing and housing designs so there is no obvious reason (to me) why the change of motor is an improvement. Three things that are different:
1. The Lingo1 high voltage amplifiers are AC coupled to the motor, which gives them a high output impedance (akin to low damping factor of an audio amp). The low voltage Lingo 4 amplifiers are probably direct coupled and avoid that problem. I don't know if 'damping factor' affects motor vibration but it is a difference.
2. The Lingo 4 FPGA generated sinusoid could have/should have lower distortion than the way it is done in Lingo 1.
3. The Lingo 4 motor is mounted differently without the turret nuts because no mechanical speed adjustment is required. A compliant washer is used and it looks like a strengthening plate to stop the mountings flex like they do in Lingo 1 (and Majik)

I see #3 as the biggest difference but if you have any insight from Linn as what they think makes the difference I would be very interested.

 

[9designs]

Hi Thomas, FYI my musings are purely rhetorical. I am not looking for any one to try and answer or counter them them but to promote thinking outside the Linn box. I am not being critical of Linn. I do expect that all their products are a combination of a priori theorizing and design of experiment listening and their track record doesn't have to be proven to me. I greatly enjoy my LP12.

I will draw a line under my plinth/suspension musings to save us both a lot of time except for motor mounting. My interest is that I've had Lingo 1 since its release but I really cannot justify the cost of going to Radikal. Lingo 4 is reportedly better than Lingo 1. If we assume that any improvement is due to reduced vibration I wonder where the improvement comes from because the Lingo1 110V AC motor and Lingo4 12V AC are from the same family, just wound differently. They will consume the same amount of power and share the same bearing and housing designs so there is no obvious reason (to me) why the change of motor is an improvement. Three things that are different:
1. The Lingo1 high voltage amplifiers are AC coupled to the motor, which gives them a high output impedance (akin to low damping factor of an audio amp). The low voltage Lingo 4 amplifiers are probably direct coupled and avoid that problem. I don't know if 'damping factor' affects motor vibration but it is a difference.
2. The Lingo 4 FPGA generated sinusoid could have/should have lower distortion than the way it is done in Lingo 1.
3. The Lingo 4 motor is mounted differently without the turret nuts because no mechanical speed adjustment is required. A compliant washer is used and it looks like a strengthening plate to stop the mountings flex like they do in Lingo 1 (and Majik)

I see #3 as the biggest difference but if you have any insight from Linn as what they think makes the difference I would be very interested.

Which is why I’ve designed my own motor Mount for my Lingo1 deck, moving the motor to its own unique top plate.
Comparison to my Radikal deck appears that it’s not missing much..

Linn always has to package upgrades to backwards compatible bite size chunks. I’m sure that has driven the development path of the deck.

 

[Moomintroll]

Comparison to my Radikal deck appears that it’s not missing much..

Have you done anything to address the hum that comes from the AC motor? I recall a Radikal demo, when it was launched, where Ian Wilson turned the volume up and swung the arm on the Lingo deck, over the record, towards the label and a hum could clearly be heard through the MC cartridge. This was completely absent on the Radikal deck.

’troll

 

[John76]

We can separate the deck into two zones, Isolation and playback. (A boundary diagram for any engineer reading and use to creating DFMEA's)
The chassis holding the bearing and arm is the playback zone, which in an ideal world will experience no external vibration. The motor, plinth, top plate etc are all on the isolation side of the equation.

We don't want any vibration crossing the boundary between the two, as that would disturb the interface between the record and the stylus., causing distortion or colorations and loss of detail retrieval.

Interesting take regarding isolation and playback. I’ve modified my LP12 to facilitate sinking of the vibrations out of the plinth to a Symposium platform designed for that purpose. Using a Linn solid baseboard screwed to the plinth with the 10 screws with four brass cones bolted to the baseboard makes a better conduit than rubber feet for giving those vibrations somewhere to go.

 

[ThomasOK]

Hi Thomas, FYI my musings are purely rhetorical. I am not looking for any one to try and answer or counter them them but to promote thinking outside the Linn box. I am not being critical of Linn. I do expect that all their products are a combination of a priori theorizing and design of experiment listening and their track record doesn't have to be proven to me. I greatly enjoy my LP12.

I will draw a line under my plinth/suspension musings to save us both a lot of time except for motor mounting. My interest is that I've had Lingo 1 since its release but I really cannot justify the cost of going to Radikal. Lingo 4 is reportedly better than Lingo 1. If we assume that any improvement is due to reduced vibration I wonder where the improvement comes from because the Lingo1 110V AC motor and Lingo4 12V AC are from the same family, just wound differently. They will consume the same amount of power and share the same bearing and housing designs so there is no obvious reason (to me) why the change of motor is an improvement. Three things that are different:
1. The Lingo1 high voltage amplifiers are AC coupled to the motor, which gives them a high output impedance (akin to low damping factor of an audio amp). The low voltage Lingo 4 amplifiers are probably direct coupled and avoid that problem. I don't know if 'damping factor' affects motor vibration but it is a difference.
2. The Lingo 4 FPGA generated sinusoid could have/should have lower distortion than the way it is done in Lingo 1.
3. The Lingo 4 motor is mounted differently without the turret nuts because no mechanical speed adjustment is required. A compliant washer is used and it looks like a strengthening plate to stop the mountings flex like they do in Lingo 1 (and Majik)

I see #3 as the biggest difference but if you have any insight from Linn as what they think makes the difference I would be very interested.

I don't know Linn's take on this but my guess would be that the motor drive is likely the most important part and that the reduction in motor vibration from the improved drive allows for the different motor mount that results in further gains. It would be interesting to know what Linn thinks but if the motor mount makes most of the difference why not use it on the Majik motor?

 

[John76]

I don't know Linn's take on this but my guess would be that the motor drive is likely the most important part and that the reduction in motor vibration from the improved drive allows for the different motor mount that results in further gains. It would be interesting to know what Linn thinks but if the motor mount makes most of the difference why not use it on the Majik motor?

The Majik motor tilt needs to be adjusted so that would limit how it is mounted to the top plate. When did Linn change the dome washers from aluminum to stainless steel? I’m hoping the Premotec motor obtained back in 2012 had the latest hardware.

 

[sktn77a]

I obtained from you back in 2012 had the latest hardware.

I think it was way before 2012. My 1997 LP12 had the steel domed hardware.

 

[13th Duke of Wymbourne]

Yes, the new motor mount is only facilitated by the speed calibration of Radikal and Lingo4.

One last thing on AC motors goes back to when Pink Triangle offered their own external motor controller for the LP12 and it came with customization to the customers existing motor. The Pink Triangle controller had adjustments for quadrature (two phases 90° apart) that could be adjusted to minimize vibration for each motor. I believe Rega do this in production and motor + controller come as a set. This was not done for Lingo1 (though it could be added by changing three fixed resistors for potentiometers). Maybe it is done for Lingo4? I don't know how much difference it makes, one Day I will get round to trying rather than musing about it.

 

[9designs]

Believe this is what the Zeus controller offers, phase adjust to reduce vibration. Probably the psu I’ll move to from the lingo 1

 

[orthobiz]

Which is why I’ve designed my own motor Mount for my Lingo1 deck, moving the motor to its own unique top plate.

Interesting, can you post a pic?

Paul

 

[pirov]

Who makes an aftermarket metal plinth for the LP 12? Has anyone had any experience? I remember that Edmund/Hercules/Mose made a four piece metal plinth.

Best,

John Hirsch
johnhirsch52@gmail.com
202-999-5563 (US)

I have a TigerPaw Stratos, with which I am very happy. TP is no longer trading unfortunately, but here's some information about construction from the website which is still accessible.

'Each plinth starts life as two solid billets of aluminium. Both blocks are carefully machined in to an upper and lower section. The upper part incorporates the top plate and the top four flutes. The lower section starts at the step of the lower flute and then continues in one piece to include the bottom tray. The two sections are then bolted together to form a rigid structure of immense strength. The precision joint is invisible to the eye being hidden by the shape of the lower flute.' https://www.tiger-paw.com/stratos

Here fyi is the review of my experience and conclusions from way back in January 2019 when I purchased the deck (bear in mind this was pre- Karousel, Radikal 2 etc):

"I have been able to home dem the Stratos via a bespoke arrangement involving Roger (Tiger Paw proprietor) and Audio T in Brighton. Roger very kindly supplied the plinth for demonstration at no cost. I agreed with Audio T that I would pay for labour involved in rebuilding my LP12 with the original plinth, if I decided against buying after living with the Stratos for a week.

Stratos evaluation

In sum, I really like what the Stratos does for the LP12 in my Exakt Akubarik system. It improves the experience of listening to the best recordings/pressings in my collection by a significant margin. For example, Paul Simon (‘Graceland’), Robert Cray (‘False Accusations’), Agnes Obel (‘Citizen of Glass’), Malia and Boris Blank (‘Convergence’), Eleanor Friedberger (‘Rebound’), Crusaders (‘Rhapsody and Blues’), John Martyn (‘Piece by Piece’, ‘Grace and Danger’, ‘One World’), Miles Davis (‘Kind of Blue’), St Germain (’Tourist’), Grant Green (‘Idle Moments’), JJ Cale (‘Troubadour’), and UB40 (‘Signing Off’) are all unequivocally better, not just different.

So, ‘Citizen of Glass’ has always sounded great in my system, but the Stratos takes musical engagement to another level. On track 2 of side A (‘Familiar’) the timbre of the piano sounds just ‘right’ somehow (same throughout the album), and the male/female vocal harmony is nning and completely beguiling. On side B (track 4 ‘Grasshopper’) the piano could be in the room (I’ve certainly not heard it quite like this before). Similarly with ‘Kind of Blue’, the piano, bass, sax and trumpet are beautifully rendered, with a kind of accuracy and realism I have not noticed before.

Compared to my Linn afromosia plinth, I would describe the Stratos as both authoritative and detailed, but also more effortless and natural. It presents a rock solid and three dimensional soundscape, with very precise location of instruments and vocals, and increased dynamics. Silences are somehow starker, and musical notes start and stop more quickly. I’ve no doubt that more information is being excavated from the grooves. (It’s difficult not to think that the increased precision and resolution are due to the turntable’s moving parts being held in a tighter grip - an irrelevant psychological consideration I have tried to ignore). I’m also hearing musical inflections not previously noticed (for example the delicate stroking of the snare drum with brushes on ‘Blue in Green’ from Miles Davis’s ’Kind of Blue’).

Of course these qualities are of no benefit if not associated with increased musical engagement and enjoyment, and this is what the Stratos delivers. There is no ‘downside’ in the sense of a reduction in the the LP12’s analogue character - the key feature that makes it superior IMO to even Hi-Res 24 bit source material via the KEDSM.

The Stratos won’t make a bad recording sound good, but I’ve played very few records that don’t sound better (though the degree of improvement is less with poorer recordings). The Stratos deals very well with thinner/brighter material (e.g. Suzanne Vega, ’Solitude Standing’, ‘Suzanne Vega’; The Christians, ‘Colour’), and even better with darker or murkier recordings where another layer of information is being retrieved from the record (Steely Dan, ‘Katy Lied’; Grateful Dead, ‘In the Dark’; Bob Dylan, ‘Oh Mercy’). Only a very few LPs have not been as good as I was expecting."

 

[John76]

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