Friday, 15 November 2019

ETF 2019

Arrival Thursday evening in lovely Belleme

What is this?

A Magnetizer - get your magnets energized right here.

Test gear

Now that is a triode.

And some steampunk...

Plaster horns and amazing woodwork

And this is a platter...
The cork is 12” LP size.

Greetings from Belleme with more to come...

Saturday, 27 July 2019

The Foundation Turntable

The concept for our new turntable has been a natural evolution over many years of observation and experimentation with LP playback. This turntable is a distillation of the best elements taken from stand out performers and combined into a single system. Garrard, Lenco, Walker, Kuzma, Galibier, Scheu, Micro Seiki, Verdier, Linn, Thorens are a few of the notable brands which passed through. The best aspects were noted, explored and documented. Myths were plentiful, good performance not so much. With time it became clear what worked and what did not. These insights and understandings created an opportunity to combine the best elements and create a uniquely high performing turntable.

The Platine Verdier is one of the longest enduring and highly regarded turntables when it is with its original “Granito” plinth. Among the experienced vinyl cognoscenti there are two classic turntables considered to be at the top of the game. One is the Micro Seiki 8000 and the other is the Platine Verdier with Granito base. I approached M. Verdier in 2012 with a request to produce the original "Granito" plinth. He was kind enough to provide his approval, mentorship, drawings and specifications as well as awarding my little company dealership of his products. 

The original plinth was fabricated in Italy and so one of the most historical Terrazzo providers in Italy agreed to participate in the research and development of our little project. Fantini Mosaici With their expertise we went through several versions before M. Verdier was satisfied with the result. The final approved version utilizes an uncommon, super hard concrete. This is combined with a Venetian selection of stones from all parts of Italy. Once it was finished and installed all doubt concerning this plinth's roll in acoustics was dispelled. Slate, stainless steel, wood, panzerholz, bronze, brass, Baltic birch, resin encased MDF, steel and combinations of the these were all tried and it was quite clear that this unusual concrete and stone mixture had a more neutral and comprehensively powerful presentation than any of the others by a wide margin.

To earth this high mass plinth Stillpoint Ultra SS filters are employed to create a solid and easily levelled platform. This footing is not only for the plinth, bearing and arm but also the motor pulley which is now relieved of any suspension movement that can cause speed anomalies.

One of the most copied platters and bearings of any turntable was developed by Thomas Scheu. The enterprise he founded provides bearings and platters for many famous brands of turntables. He also created one of the best sounding, ingenious, no-nonsense turntables of his own. Since he provided kits and parts for DIY’ers, many who started with these kits took his concepts and created companies such as Feickert, Teres, Red Point and Galibier with them. Even as they deviated from his original concepts there is no question he inspired them all. His bearing, like the Verdier, utilises an inverted configuration but with more modern materials and understanding of oil cohesion, adhesion, surface tension and capillary action. It is a simple and ingenious design which re-lubricates itself after initial servicing and is relatively maintenance free. 

The Scheu platter employs a high precision, acrylic of special character. It is harder and more dense than most of the acrylic material family in order to achieve a specific goal. The speed of sound through this solid is precisely that of vinyl. I have observed, first hand, this measurement with the specialized measuring equipment required. The result is like playing an 80mm thick, 7.5kg LP record.  There is great solidity with an inner, natural voice that is unique.

The arm pillar and motor pod are made of fibre reinforced concrete to marry plinth, platter, motor and arm in rigid geometry with excellent acoustic properties. The result is a resolute and steadfast loop between groove and stylus which reads microns accurately.

The original Verdier bearing is an hydraulic bearing - not a magnetic one as many believe. Although the magnets (ingeniously) neutralize the weight of the platter, the bearing remains and influences sound according to its hydraulic state. When the oil leaks, which it inevitably does, air gets in and compromises the sound. Purging this air once a month or so is required to maintain best performance. When I complained of the need for this routine and suggested ways to prevent the oil leakage to M. Verdier, he chuckled and encouraged me to try. Many already had...

The Scheu bearing is similar in configuration and geometry. It is also an inverted bearing grossly overrated for its weight bearing capability and uses materials and tolerances which were not available or common in the era of the Platine Verdier. This bearing couples the platter with the plinth through an inverted ceramic bearing which is irrigated in a an oil bath. The result is a dynamically stable, ultra precise, low noise rotation with direct coupling. The later models of the Verdier, the Nouvelle Platine and the Magnum both use hydraulic circulating bearings. This is not a coincidence.

Readers of my old blog may know that I believe the heart of the turntable is often the most overlooked component - the motor. While there are endless discussion of tonearms, cables, cartridges, platter mats and supports the motor is normally overlooked and yet plays one of the most important roles of any component. It is the active component which not only provides the motive force, but also the reactive element to stylus drag. The motor's reaction to this ever-changing source of friction fundamentally influences how a turntable sounds. 

Idler turntable fans attribute this influence to the drive mechanism. Most idler drive turntables use large, shaded pole, motors which compensate for changing load with inductive inertia. Belt drive turntables most often use small, ac synchronous, motors which look like peanuts when compared to these idler juggernauts. Our experiments showed conclusively that motors type makes a greater difference than drive type.

As a result we determined that different types of motors and how they sound are commonly labelled as “idler" or "belt" drive and that this labelling is misleading. The Verdier uses a powerful, precision DC motor which causes many idler enthusiasts say that it is the one "belt drive" motor that has any soul. M. Verdier kindly points out the motor's merits in a Sound Practices publication article - issue 11. 

The grip, heart and slam of the “idler” as well as the fine detail, harmonic decay and ambient information of the best of “belt drive” is to be found with this motor. To build on its strengths and to eliminate its weakness a completely new controller has been created. In the era when the Verdier controller was developed the LM317 voltage regulator was probably an advanced device. However today there is a greater understanding of motor control. A motor acts as a generator in operation and this back EMI causes error in controllers like the LM317. As a result they fall in and out of regulation erratically. There are newer chips designed for motor control which are immune to this problem. There are also circuits of greater sophistication which can self correct speed variations without the complications and problems of closed loop feedback.

Our contoller not only provides rapid and high current delivery but is also not thrown out of regulation by the EMI coming off the motor. Additionally, this controller senses motor load and prevents resulting sag to maintain speed as the load varies. This is a simple and elegant solution which behaves much like the inductive stability of idler wheel shaded pole motors. There is an adjustment which allows tuning of this electronic inertia and provides adjustable degrees of robustness to load changes during transient attacks. One can readily find the desired presentation as well as hear the difference this circuit makes by turning it on and off.

The high degree of mechanical integrity provided by these elements combined together: plinth, bearing, platter, a notoriously good motor and now powered by a sophisticated controller to provide a new perspective in LP playback. The result is music with all its power as well as its nuance.

Appearance is a simple, subdued, mid-century modern to fit any decor.

To accompany the Foundation Turntable we also can provide Dynavector XV-1S and Kuzma Stogi Reference 313 VTA Tonearms / Cardas Clear wire, on request, for a proven, optimum combination. No-nonsense Vinylista tools of world class performance.

For orders send us an email. 

We committed to a small production run which has now been filled however we will reopen production for further orders. Lead time is 60-90 days.

Thursday, 11 July 2019

Life in the time of Hay...

A cool and rainy spring gave way to a ferocious beginning of summer. The hottest days ever recorded in France. As a result of this sudden change the farmers came out in synchronisation on the same day to get the hay in before it was lost.

While the farmers have been out in the heat cutting, drying and bailing the hay it has been a busy time indoors as well.

Mojo the mad is a constant companion...

constantly chasing everything (real or imagined) ... 

In trying to stay with the real let's get on with business then, shall we?

Our Field coil design has moved forward.

What started as a simplified way to improve on the historic Tungar battery chargers and Selenium rectified supplies and solve the requirement with a sober design created an avenue of discovery. 

It began with a Schottky rectified, choke loaded design which eliminates noise and its harmonics and provides current stability and storage.

Voltage regulation was tried and was the wrong direction.

Current regulation and turned out to be an excellent solution for field coils, improving sonics considerably.

The difference in the type of AC transformers was more pronounced than anticipated. Split bobbin types were used initially to decouple line noise. R - Cores were tested and were quieter in operation. When toroidal types were tested they demonstrated clear superiority in current delivery. While the other steps forward were solid and clear, the difference of the toroid was pronounced. Quite a treat to experience how much better the music moved and flowed with greater weight and agility above the other steps forward.

Field coils deserve better supplies because they make a field coil more of a field coil - meaning the increased stability of the magnetic field in the face of constantly varying load. The difference in quality of supply is easy to hear. 

 The supplies pictured above are heading to the Island of Crete to power WE555 6-7 volts / 1.5 amps with plenty of headroom. 

For those who would like to update their supplies please contact us by email.

Sunday, 23 June 2019

More Mojo

It has been a busy first half of the year with orders and new projects. Here is a pair of Mojo III heading for delivery. 

The main driver has been updated with new CNC wound field coils and improved magnetic pole pieces and magnetic design. One of the issues with these field coils is that they only open up after 24 hours of power up. No matter how much we tell people this they don't really believe it until after the first 24 hours, after which, they excitedly inform us of how essential this is. 

Dampening plate details... to handle the extra energy and preventing the aluminium from running away with it. 

Mr. Slagle's excellent nickel core magnetics.

The crossover has been updated to very good effect. This has created a new version of Mojo.

The paint work is evocotive of a dust storm with its varied colouration. This pair is heading for West Texas. Run in material will probably include some Thunderbirds and Stevie Ray Vaughn - just because....

In the background is some foreshadowing of a new project - the Foundation Turntable. More on that in a following post.

So here is the new Mojo version 2, looks the same, sounds significantly better.

We have been busy and will post again soon. 

Until then, burning the midnight oil and making lots of noise.

Tuesday, 23 April 2019

Field Coil Power Supply 2

The beginning of a well engineered field coil power supply steps around the audio fashionable - both the vintage Tungar types and the commercial and cheaply made capacitor loaded variants. Experimentation and experience reveal that a split bobbin AC transformer, Schottky rectification with an input choke load lead the way to best performance. A tuned reverse recovery spike filter (snubber) and a 220nF cap to soften dynamics in the choke improve performance further. Rod Coleman’s well designed and evolved constant current sources on the output ensure a constant and stable magnetic field for the voice coil. Not as poetic as museum caliber vintage but performance offsets the collectable caché.

Split bobbin AC transformer prevents coupling line noise to the secondary. 

Schottky diodes into a choke load follow as an excellent and well documented rectification solution:

"... a properly designed choke-based supply's ripple is a perfect sine wave, with no high frequency noise.

Silicon diode types except Schottkys emit a burst of ultrasonic noise as they turn off. This noise can go forward into the load circuit and back into the AC line where it can also excite transformer resonance. The "slow" diodes still have this ultrasonic noise. Schottkys are the only type which do not. Schottkys also have half the voltage drop of other diode types and are usually faster. 

... With the choke there is no steep high current pulse, so no disadvantage to Schottky diodes. You get the advantage of no ultrasonic noise, lower voltage drop (so lower power consumption in the diode) and no big massive current pulses."  - J. Swenson

The superior voltage stability and regulation of an ICPS (input choke power supply) is well documented.

In summary there is nothing rare or esoteric used to achieve better sonic result only sound attention to what the energy is doing and what devices work best regardless of mythology or cost.

It could be said that building these in the springtime of the French countryside adds a certain "Je ne sais quoi" or that the local wines mellow the impression...

... but, in fact, it can be discerned quite easily without augmentation as the magnetic field is more stable, with ample, dynamic and clean power, and this provides a smoother, more nuanced presentation. 

It was then left to be discovered if two could be fit into one…

And so it was done - two into one.

Half the chassis + twice the time = same cost.

Provide the voltage and current requirements and we can build one for your field coils - vintage or new. Just send us an email.