Incredible close to music II – Fascination with the Wide Range Horn

Shindos modified cartridge, based at the famous Ortofon SPU-A

Today I am following on to describe Mikes Verdier-Shindo-chain already featured in my last article. I did describe Mikes tremendous care taking about any little detail having influences to the final performance of his set audio up. Since almost 30 years he does have struggled hard with the progression of tiny steps of improvements within his personal audio chain, always interrupted by setbacks from missing estimates and irritated by wrong conclusions. If you have an idea for what you are looking and if you don't expect the easy way of "pluggable components from the land of milk and honey", than you will have the correct prerequisites to build up a audio chain able to perform within a higher degree of harmonic properties. Instead of solely ingenious technical comprehension, a solid portion of common sense, consciousness, experience, sensitivity and refined spirit, will be the major properties to extend such a performance into real life instead of stunning superficiality of HiFi.

Wall panels fixed with special wooden washers to the underlying construction, at the left additionally covered with quilted fabric

One example might show perfectly what I want to describe. Almost everybody with quite extended audio experience knows, that the physical surrounding room conditions of such an audio set up will hardly define the acoustic limitations of its performance. The room with its shape and size, its materials and its reflecting surfaces will have a tremendous influence to the perception of the audible spectrum. Since generations specialized architects are designing highly improved wooden surfaced interiors for the professional classical live music performance in concert halls. Mostly archived with a highly complex angled, extremely structured, massive wooden panelling surface, it is a common strategy to disperse and harmonize the reflective portion of the wandering waves. The damping of their inherent energy with their transformance into heat using solid wood masses, is a wanted effect, in order to obtain a refined aural spectrum of harmonies as a advanced stage for natural instrumentation.

Mike did once line out his listening room with a highly complex structure of massive wooden panels in order to create a similar effect. A solid support frame from pine pales dowelled to the massive brickstone wall is the under construction to take layers of long wooden panels. Each panel is fixed with several wooden washers to the underlying frame. Within this construction it is possible to keep each panel movable and fixed at the same moment, in order to take out the best portion of energy, reducing high amounts of reflected waves. Very important areas of that wooden lining are covered additionally with quilted absorbent cotton tissues, like the ceiling area above the speakers. When I do remember right, Mike did spend several month only with evaluation of improvements coming from different wooden linings in his listening room, before he did set up his audio components for listening.

A completely different stage of refinement can be archived with controlling the raw electrical supply conditions. The electricity as it is supplied by the local distributors, is generally not free from high frequency detorations and peaks arising from high energy switchings of industrial production or traffic.
A early pretransforming process together with a hf-filtering effect can be archived with huge variacs for the line voltage adjustment. Mike has built for this reason a variac switch box, were all his audio components are supplied with smooth electrical input.

Switch box with variacs for the complete audio system

Another important item is his component support system, called "Die Bank" (the bank) at the time distributed by Auditorium 23 and manufactured by Norbert Gütte, the carpenter who made the wooden speaker enclosures and record player plinths for them, today with his own company Lignolab. His massive component support system is balanced and isolated by air suspended feet. Its sheer weight, made from 100mm thick pine plywood panels keeps the amplifying components and the record player free from room inherent resonances. Such physical effective components bring out a tremendous portion of refinement into a given set up. Instead of bling-bling-hifi-accessory like "golden clothes pegs", "enhanced cable electronics"and other similar nonsense inventions of the hifi markets, coupling devices with real physical effects can have a tremendous influence to the perceived harmonic properties of such a chain.









From my point of view a well working audio chain is able to show a bunch of properties beside nice sound. It should be able to transport the inner and outer structure of music without any tiring of the attentiveness to the listener. Such a set should be able to show its physical abilities with a foremost dynamic performance and refined harmonic subtlety, in short a almost natural modest behavior instead of intrusive superficiality. Commonly this sort of superficiality is connected to a definition of "HiFi", were always more is equated with the term better, a typical value scale of commercially marketed products. But when "more"will be substituted with a more complex internalized and subtile listening experience, were the reference is set close to natural acoustic instrumentations within real music, it can be clearly experienced, that such a performance in a foremost stage depends on absolute contrary properties than such superficial effects. A advanced performance with a more unobtrusive manner without any effects, need a higher degree of conviction work in sales processes, its success depends mainly on positive experiences made with well made products, together with comprehensible presented arguments. Both are elapsing scarce goods in todays commercial audio world and its distribution culture, continuously opening a gap which is merely closed from magicians, bag thieves and from gossip in web communities. A development which makes a tremendous turning to vintage audio products from the "golden years" comprehensible. This process started at the decline of audio development in the 1970ties and is still growing, even when Ebay has already cleared off the cellars of the western world during the last decade. Within this routine lots of vintage audio products have been washed up to regions, were these originally never have been part of the market. In the former Warsaw pact countries a grown interest into the not available myths is obvious, as all far east countries are now in the race to catch up with Japan and Korea as pace setting nations for more than 40 years in that field. Now Hong-Kong and Singapore, both in a economic advanced state, seem to overtake the main investments into vintage audio products and seem to be the spearhead of its final end. In the originating countries of this culture, as in the from western ideals dominated consumer culture, the ideas of storage less cloud streaming and equipment exempted listening of audio to go have turned the wheel of "progress" into nirvana.

The LM22A/555W combo with LM597 high frequency field coil driver underneath,
decoupled by a spring suspension system

Since two years now Mike harvests the fruit that he has sown over decades in his own audio history. Before that stage, he was in a permanent process of search and exchange, I think a lot of yours will know what is being meant with that phrase. Caused with the acquisition of the big medium frequency horn units, all positive advantages of his before summarized components are adding up to a higher degree of fidelity. The key was the Line Magnetic LM22A with LM555W field coil driver, which makes a physically advanced perception of audio possible, like no other principle. It can be seen more like a music instrument than as a receiving and transmitting device. A two inch diaphragm made from thin foiled aluminum, with quite movable surrounding, in a field coil operated magnetic case, amplified through a almost 2 meter long horn development through a 0.75 x 0.75 meter sized opening, which performs the frequencies from 300 to 7000 hertz, is not only a rare and unique audio transducer, it is physically working like a music instrument on its own. The radiated waves distribute air very similar to a common known instrumental brass horn. The human male voice as tonal scale, a bass trombone, a cello and a tenor sax perform almost the same frequency range, seamless covered by this outstanding audio transducer. Like these original voices, it is able to release its radiated energy with a comparable ease and in a unconstrained manner, since its length of development and its minimal moved diaphragm weight. Comparing this weight to a 8 inch paper cone, it is just a tenth of its moved mass and this fact declares the outstanding dynamic properties and its inherent low distortion properties.

Basic physics lecture: horn mouth sizes and dedicated frequencies, I think this figures are very gracious valued comparing the real.

If you let melt these facts on your tongue, than you might know, that the air is getting thin in this region of loudspeakers with similar properties. There are beside the authentic Western Electric horns only a handful other designs, which are made to follow on physically. Such a mechanism works hardly at the edge of physical and technical limitations, even by today standards. Sitting in front of its refined radiation, these horns show a insight into the music with a incomparable ease and unobtrusiveness, a paper cone device cannot physically compete with, nor does it have any chance to convince. The incomparable refined wave distribution, which gives you the feeling that its sound is not of mechanical origin, is released in a manner were its wavefront seem to pearl out by itself instead of being pushed, the common impression even with the best cone speakers of smallest size and best alnico magnet motor. I am sure a lot of yours know and value by own impression what I try to describe here from high frequency compression units, but here we are talking almost about the a wide range frequency distribution of a full range unit. No other loudspeaker principle shows the same properties and abilities this design can offer, no full range driver (independent of its size and weight) and no other transducer principle like electrostatic-, ribbon-, plasma- transducers shows the same summery properties, like this originally western electric originated design. Of course it is not free of any problems, like with every other design, the advantages against the disadvantages have to be weighted, the 22A horn with LM555 field coil driver is one of the best compromises one can do. If the money preferences in your purse will not set you off the guest list, you will get a ticket to a club of owners, were world class performance within the most important part of the frequency spectrum is the lowest common denominator.

Original drawing from Western Electric from the 1930ties.

LM597 field coil high frequency horn on top of
WE inspired dipole enclosure with Klangfilm KL405 woofers 

Read on soon about the frequency extension of the horn into both directions and the crossover strategies resulting for a balanced performance with holographic attitudes, Volker

Incredible close to Music I – The System Matching

Hello again to all interested reading this blog. Today I want to continue with the series of posts dedicated to extraordinary audio transducing systems. I am going to present here in my blog some unique stereo systems, which I do personally know very well and which I do prefer a far way about others. I started this series almost a year ago with Klaus' Tannoy Autograph based system, which needs to be followed by some final posts about his professional tube amplifiers.

Today I want to report about a system, were the amplifying chain is completely relying to the qualities of one of the most important tube amplifier designers of our time, the shortly passed away Ken Shindo. Tube electronics of this master are designed as single components in technical terms, but their major effect will be shown when matched together to a chain. A tremendous advantage above the most other tube components is their complementary characteristic of higher order of musicality within this match. A chain of amplifying devices (transformers, components, tubes, cables and their technical principles together with mechanical details) create additional physical abilities and psychoacoustical effects. Here the summary of harmonies, dynamic details and musicality in general make a completely different reception of music possible. Every audio chain does, with tube components it appears in a advanced stage, but only a handful designers do take care about the importance of matching effects. Ken Shindo was one of the few, who was able to create sound systems, which have the ability to keep the inherent structure of music in a comprehensible flow. Almost close to the listening at natural instruments, his amplifiers make this sort of listening ease to one main sensation and criteria, independent of its technical implementation.

Platine Verdier with Shindo Mersault tonearm and Shindo Cartridge mounted with
A23 bell bronze base, next to Shindo Monbrison preamplifier
(most underrated extra: the Fissler pressure cooking seal to damp the light weight platter)

As seen, the today bespoken type of components it is not of foremost importance, but for the sake of completeness, I will list them up. I did listen to a Arome step up transformer at a Monbrison preamplifier and a set of Shindo WE 300b monophonic power amps. All components were equipped with vintage original tubes from Western Electric or RCA. As main program sources vinyl long playing records via a Platine Verdier record player was used with a 12'' Shindo tonearm and a Shindo modified Ortofon SPU pick up system. All components have been chosen lined up in their design by its creator to bring out a refined tonal expression, were technical performance will be almost forgotten.

Shindo 300b Mono amplifier

The other alternative program source was a digital music player system, based on a Mac-Mini and a RME Dac, purely non Shindo orientated, till its analogue signal insertion into the Monbrison line preamp section.

"Die Bank" as heavy wooden shelf system with air suspended feet, inside the digital
streaming client with RME Dac does not create any dissent comparing the
300b tube amplifier underneath

Of course the Platine Verdier as major source has a tremendous impact to the creation of the overall sound. Like any other analogue component in the beginning of a audio chain (pick up, tonearm, step up transformer), the record player is a major sound creating component, like a true natural instrument. Anything wrong, loose or missing can not be compensated later on, anything to prominent will be amplified to further dominance. The unique heavy (50 kg) magnet bearing player was born in 1979 as an prototype of its designer Jean Constant Verdier. A resulting summary design from the former production of a classic sub chassis player "Era", which was very similar in principle to the classic Thorens TD150 or its Linn derivate LP12. In the first step the "Platine Verdier" was a concept shown in the french hifi magazine "L'Audiophile" intended to be a diy instruction. The magazine was run (from 1977 to 1995) by another major figure of the audio world, Jean Hiraga. He formally reintroduced the merits of a direct heated triodes in power tube amplifiers and their technical history to the non japanese western world in the late 1970ties. In Japan enthusiasts had been using and collecting vintage audio treasuries since the 1960ties. In the early 1970ties some groups organized shoot outs about vintage tubes and their dedicated amplifier designs in order to find out about their aural differences, Mr. Hiraga was one of driving figures there, before he left Japan for living in Paris with his presents from Japan. With his book "Initiation aux amplis a tubes" he prepared the ground for a very special interest, which is still growing, even when it had its peak some years ago in a time, when hardware less music was not the main issue in audio. In "Maison de L'Audiophile" in Paris a small group of audio enthusiasts made regulary demonstrations in little cinemas with their own amplifier kits (300B), Onken enclosures with Sato MF-horn installations, Altec HF-horns  and of course Jean Constant Verdiers turntable. I do remember one of the demonstrations in Paris of the late 1980ties, which was as one of my major initial experiences leading into my own long and winding way to Fi.

Installation at Maison de la L'Audiophile in Paris in the 1980ties

Coming back to my matter of concern a time of 25 years has passed by and almost all the time I do know Mike, who's set up is in the center of discussion today. I can remember a lot of different components in his room, almost like in a hifi store, when I met him the first time. He was already well connected to several ideas of Jean Hiraga/L'Audiophile through Auditorium 23, a german outside post for similar ideas and distribution of some of their products in these days, run by Keith Aschenbrenner. He is the most  driving figure in Germany for music reproduction without compromise til today, more about his ideas in other posts. From the outside the interested (infected) group of aficionados connected to A 23 looked a bit like a religious conspiracy circle with dogmatic theories, than a loose group of people which share common interests in a complex funny hobby.

Mike used a lead battery operated phono equalizer together with different tube preamps and a sheer uncountable amount of different tube and transistor power amplifiers for alternative testing. He worked beside several Thorens 124 at a record player concept, which was basically made from three different sized lathe chucks, one hold the main bearing for the heavy platter, one kept the motor unit and one to hold the SME 3012/II with outside fixed Isoda cabling and a lead housed Denon DL103 cartridge, the hole installation was set in a sand filled wooden box of 100 kg, just to recall some of the ideas coming from France these days. He already had ordered the legendary Partridge Transformers TH4663 through La Maison de l'Audiophile for building his own pair of legacy 300b single ended amplifiers with the WE310 as driver tube.
Many components have passed through over that time, for example only to name the loudspeakers was a whole lot. Seriously it started after some ordinary hifi speakers from the british 1970ties school with  Lowther drivers and with Audiovector enclosures at the end of this lane (front- and backloaded horn). Followed by Salabert PHP drivers in different types of enclosure types, mostly open baffles. Both speakers are full range 8 inch speakers, which were used from a basic underlying theory, that a crossover less, small scaled single driver does show the fewest errors and the best homogenious sound… Every theory is only as good as its successful contradictory idea.

Line Magnetic LM22A/555W field coil receiver unit

Today after more than twenty years later we are looking not only to the opposite design principle of  loudspeakers with three or more devided frequency paths per side. We are looking back into the history of audio design, when professional audio transducers were designed to fill cinemas and theaters with low power tube amplifier systems with reasonable sound. A time, when companies like Western Electric, RCA, Jensen, Klangfilm and others layed the pioneering ground for a century of audio engineering with exceptional efficient design ideas and perfectly crafted products for professional dedication. Today the food chain has already turned around and the sheer power of 1000 class g watts can be archived in a shoe box sized enclosure together with a room equalizing computer and a loudspeaker to form a almost errorless measuring system.

The need for room filling horn enclosures with heater like radiations from 6 watts tube amplifiers is based on pure luxury, but not at fundamental demands. For this reason several asian ( japanese, korean and chinese) companies do fill the gap of demand, created by the rarity of the original collector items with very close made reproductions for the every day use. Western Electric like amplifiers are made with original spare parts since decades as their transformers are wound on original WE iron cores by asian enterprises. A chinese specialist from HK, Mr. Wu and the japanese company P&G in Tokyo are highly specialized in that field. The US american government had sold ships full with industrial junk and waste in the early 1970ties to China in order to get rid of it. Tons of military, telephone and other equipment gathered near Guangzhou, were it formed the largest spare part junk yard for the Western Electric audio aficionados in history.
Not only the amplifiers but as well WE Speakers, drivers, their parts and a diverse range of horn funnels are made as perfect reproductions mainly in Asia. GIP company is a well known since decades in Japan or Line Magnetic now in China are doing replicas of original Western Electric horn assemblies and drivers with a high degree to the authentic originals. Single WE horn funnels as perfect replicas are made in Italy and Korea with a lot of empathy. All this enterprises exist since the originals have completely disappeared to collectors hands (mainly in Asia) and are even with real money not anymore available. In the closely past years real clashes were apparent in several internet forums, were interest holders of both lines are fighting about sovereignty of quality against each other.

Line Magnetic LM555W field coil receiver

To me as an WE outsider it looks to be a pure academic question, how important the differences might be? Who will have the option to compare, with personal experience, such systems side by side for superiority? Nobody, not even Mr. Janukovitch had beside his collection of russian and chinese state limousines, the Lincolns and Mercedes' to compare originality, even if in this case the performance differences might been more than prominent.
To me the question about such horn installations is absolutely not a question of originality. For me it is in the foremost stage a question of properties such incomparable designs will have to offer. For me the principal design values are dependent, for example a horn design itself, its shape, its lengths comparing its development, its used materials and its therefor resulting resonances, its physical abilities, its electrical efficiency, its usable frequency range and finally its ability to bring me emotionally into the music event – and make me to forget any theory about.
From this point of view it does not interest, if it is branded with WE22A or LM22A, if their physical appearance is almost identical. The Line Magnetic clones are as close as it can be by material match and built quality. But their biggest advance, their unrestricted availability in new made reproduceable amounts, made possible, that even I will have a chance to listen to their unbelievable fantastic sound properties.

Coming back to my main intention, I want to write about a unique audio set up with the listed loudspeaker transducer installation. A Line Magnetic LM22A medium frequency horn with LM 555W field coil driver, expanded a with a LM 597 Tweeter and a pair of Klangfilm KL405 woofers to complete the installation in a WE design influenced low frequency dipole enclosure. To make a short cut to the late end of this series of articles, this set up is one of the most musical inherent systems I have heard so far with the best natural response I do know. Within the following articles I will try to explain why it is and why it is not possible just to spend money to get it.


Read on soon, Volker

A 12 inch Wooden Tonearm

Hello to everybody, this week I want share something untypical for the TrueFi blog and my understanding of the analogue audio chain. As the most people know, I am selling a conversion kit for classic SME tonearms. This conversion is dedicated to the classic medium weight arms into the heavier and stronger MK1 version in order to improve the pick up process with low compliance cartridges. The famous Ortofon SPU, the Denon DL103 and the more expensive japanese handmade cartridges from Koetsu, Ikeda and several others will tremendously profit from the heavy weight armwand. All existing twelve inch transcription arms are medium weight arms, so my kit makes a lot of sense to improve the dynamic abilities with this cartridges.
But there are some other extremely good vintage moving coil cartridges which unfortunately do not match the medium and heavy weight transcription tonearms. They were designed mostly in the later 1960ties or in the 1970ties when high compliance was advertised and all makers followed to nowhere. Here the famous Supex cartridges as predecessors of the unique Koetsus and their equivalent Linn cartridge line made by Supex in this time has to be named in a foremost stage. As well the successor of the SPU, the Ortofon SL15 is a wonderful cartridge almost a copy of the SPU with alnico magnet, similar assembly but with 15x10-6cm almost a high compliance cartridge. Some exotic cartridges of the 1970ties like the Toshibas or the Sonys need a lightweight arms to work with the best dynamic response. So what to do?

For this reason I always liked wood as light weight material in mind, wood has very musical properties and can be machined easily. I always wanted to test a wooden arm wand in my different SME tonearms since years, I never made it work. But I did buy rounded wood strips made from different wood sorts years ago for this reason. I had bought several broken tonearms in order to check their compatibility for my plans, a whole box with arms was stored away some years ago. So now it came into proof, I wanted to test it out.

Metal cased micro ball bearings

For that reason I looked for well designed bearings with low tolerance clearance either
for the vertical support and as well for the horizontal axis. Low tolerance micro ball bearings are in demand, if the material will be wood. The combination of relatively soft materials, like wood and precision metal work is a delicate design approach. First I did weight the standard stainless steel arm wand without interior damping wood. My ss armwand weight around 50 g, a comparable sized stick of hard wood like mahagony, oak or walnut differs around 20 g. If the cartridge holder is made as well from wood the completed armwand has almost the same weight like former used aluminum tubes of the originally 9 inch long tubes. This has another advantage, the counterweights can be still used even with the longer arm wand. The design has a overhang of 308mm and the cartridge carrier is angled off 18°. This geometry is a quite common design and is used be several arms of this length.

Wooden armwand from underneath, closed slot and a piece of copper foil for earthing the wirement

I had to cut a slot from the underside into the woos stick. For that reason I needed to make a tool to fix the round stick in position, when it will be tracked at my table saw. So I did cut a 2 mm wide and 4 mm  deep slot into the underside of my stick. I did use walnut for both parts, the armwand and the cartridge holder. Into the holder I did mill two slots for the standard 1/2 inch mounting of the cartridges. As internal wirement I did use my silvered copper litz with teflon insulation. In order to prevent hum problems the four wires needed to be screened in the wooden stick. Here a thin copper foil was used to surround the four cables. This copper foil together with the metal parts of the bearing assembly got wired together and lead out for separate grounding.

Unfortunatly this new arm is not the luxury edition, it does not have any extras like lowering device, vertical tracking adjustment, gravity free pressure alignment, a anti skating mechanism and variable geometry. It is simple and very basic, it requires one qualification – a "quiet hand".

Coming to the real experience with this tonearm. I have set it it up at my Platine Verdier turntable, mounted were normally my SME 3012 (MK1) is located. My standard pick up is the SPU Gold with the bakelite headshell, I did mount a Linn Asak (made by Supex, identical with Supex SD1000) directly at the holder.  This cartridge is very similar in characteristic with the SPU, its very dynamic and musical. Taking into account that now here a standard cable from silvered copper litz  was used, the first impression had a quite fresh taste. I did expect a very smooth, let us say more than that, a over mild general characteristic as first impression. But it came out different, a solid quite balanced soundstage of good depth and width was the first impression. Of course it did not have the pure dynamic attitude coming from the stainless steel armwand with the SPU in favorite task, but the combination was still a lot better than the cartridge with the heavy SME or even their standard aluminum armwand in the 3012. I switched to other program material. With classic music, for example with larger scaled orchestral music or with string orientated chamber music this combination is very good. A brilliant refinement of the complete mids and upper tonal range is the result of the damping qualities of the wood, the other side of the medal is a little lack of attack and dynamics. The domaine of this wooden arm is not the dynamic jazz ensemble, were punch is a important part of the realm coming true, but even there the arm works quite well. It has to be seen that this approach is a quite cheap alternative to other twelve inch arms in the upper 1000 plus region. I like its purist appearance in design, function and materials. It is an approach towards musical performance, for that it is a bargain...

If there are some interested people out there, which would like to have such a wooden twelve inch arm, you should get in contact with me. I will have some of these and they will be sold piece by piece through Ebay soon. If you are interested, you might make me an offer…

Read on soon, Volker

German Wunderkind Revisited – Michael Wollny Trio LP

Hello to everybody reading my blog. In November I did already mention Trio EM as a wonderful talented young german jazz trio. Amazing new ideas about jazz music, wining prizes over prizes,   Michael Wollny is extremely creative with unbelievable output, a skyrocketing career. Here his newest piece "Weltentraum", came out last week. It is in a way a bit different to former performances, it is finer and more subtile, less dynamic, almost intimate in musical character, it is wonderful to listen to.
As far as I do know, his second analogue long playing album, – it is as well a brilliant recording were the older cd's often lack a bit of this quality. ACT did release this record in parallel with cost free mp3 download for the buyer !? Get it, it's just amazing good music.

Read on soon, Volker

My Recommended TrueFi Web Resource List

I just want to offer my reading list of the most interesting web resources about audio equipment to all interested readers here. I have collected within the past 20 years several thousand web links dedicated to vintage audio or tube amplification in order to get informations about quality orientated audio gear. My foremost interest always was and is straight non commercial, my approach is always directed towards refinement and deeper understanding of the distribution of musical information in audio systems and of course to the music itself. So is the blog.

I have no interest in link exchange processes, like it is practiced throughout the most webpages in order to widen a purely theoretical effect of community or to feed the servers of the NSA, it will happen anyway. I will be very open to real contacts with real content. So I just do start with a small list of actual proofed links dedicated to rare topics as a extension of informations in the main issues of my blog. The list will be continued throughout the coming future.

Some of these links have been posted in some of my articles already:

Interesting new blog
http://mellowgroovy.blogspot.de/2016/02/pandcpreamplifier.html

The most subversive US-american web page about audio
http://www.meta-gizmo.net/Tri/index-1.html

The forum were Western Electric systems are in theoretical exchange

Western Electric 15 a- your opinions (page 11) - Loudspeakers - Lenco Heaven Turntable Forum

The most busy forum about collecting vintage audio in the web
www.review33.com:影音天地

A tube amplifier designer who has built them all
手作りアンプ工房Valves' World

A japanese company specialized in refurbishing, rebuilding and restoring WE amps
pandcampkit

A american diy resource about the WE/Altec 755 and other projects
JE Labs

The Klangfilm resource
http://www.klangfilm.org/index.html

The japanese collector
http://www.gokudo.co.jp

A very interesting japanese page about the pick up technology
カートリッジ

A page about food and tube amps
ものつくりの部屋

The Leak collectors reference page
H.J.Leak and Co. Ltd.

A japanese company which copies any historical loudspeaker enclosure type
スピーカーエンクロジュア（BOX）　ユートピア製品一覧　Product

The most advanced designed preamplifiers using DHT tubes
http://vinylsavor.blogspot.de

The most subjective interpretation of tube amplifiers made in a japanese bar by Sakuma San
Direct Heating

The company page from Line Magnetics (WE gear and other vintage stuff)
丽磁音响有限公司

The best WE 15A replicas
http://www.audioanthology.com/audio2.htm

A WE 16A replica from Korea
http://we16ahorn.blogspot.de

One of the most comprehensive blogs about audio
http://twogoodears.blogspot.de

A blog about the production of the replica WE 16A horn
http://we16ahorn.blogspot.de

The Tannoy collector resource page
http://www.44bx.com/tannoy/

The Western Electric resource page
http://www.moviemice.com/we/index.php

The deepest understanding of audio components as music transducers in Europe
http://www.auditorium23.de

Take care about your life, the images show where it might end up, either or?

Read on soon, Volker

A Tannoy 15'' Enclosure for the Enthusiast – The Realisation IV

Today I will report about my second week living with the new enclosure type. Living means on the first hand to get acquainted with them and on the other hand to optimize their performance in a lot of little details to improve their ability to perform like a natural music instrument. As already described, the first listening ended with a unforeseen disaster. With the strengthening and tightening of the construction (i.e. the backboard of the funnel/baffly board) a unbelievable deep, crisp, creaky and colorful low frequency response came up. This sort of response I never have heard before with a Tannoy Dual Concentric speaker, it was just breathtaking. The open baffle type cabinet with its fast, dry and extremely undistorted low frequencies made this lf-response a sensation.
But to be honest, like always, when a particular property shows up with a foremost character and over boarding quality, it happens always at the expense of others, in particular with a full range speakers. In my new cabinets the response of the highest frequencies has got influenced very well from the stiffened mounting. The easy natural listenability had suffered, the character of the speakers has now grown very prominent and superficial. This is never a good sign…

The baffle board and the mechanical attachment of the speakers seem to be are a very delicate part of the most designs, it was with all my former cabinets, but here with the support of the horn its influence is tremendous. Sometimes I do ask me, if commercial made speakers (like Altecs, Jensens, Tannoys, JBLs, etc.), ever have been evaluated so critical about all this little details before they got introduced into the market. I really can't believe this, if their designers will have taken this important detail into study? If, there would be other alternatives in mounting big chassis to the baffle boards? With solid full range types or other sorts of duplex speakers a wide range of different sound attitudes can be achieved, just with more or less solid consolidation to the baffle boards (i.e. one built chassis with a covered frequency spectrum from 50 to 10000 hz minimum).
Since I did use the front loaded horn, in particular with DHT preamplification, I have got used to a perfect transparent high frequency response without any hardening or any other sort of degradation. With its wide open, deep and spacious projection, its extremely transparent properties the funnels did engage my main ability to preserve them into my new design. But now, with the new stiffed cabinet, some of this silky response has got lost towards a more technical performance, as well grown to a bit cheeky side. I cannot accept to loose my beloved and very important attributes, so I started a venue to find this refinements back. Such enterprises are always a part of the similar game, independent if the trip will enter electronic wonderlands or like here, the relationships of mechanical resonances between design and built materials. My aim is to shift the existing resonances in the radiated frequency spectrum up and down, to emphazise were these can be damped, were they are mostly annoying and finally might support the general performance.

Stiffening of the back board, as well can be seen the tight mounting of the chassis with metal screws

As a first test I exchanged the stiffening board against solid underpinning struts, in each cabinet two of them did resemble the massive boards. The effect was as expected, the wonderful creaky deep bass was gone and a bit more wooly and soft indifferent low frequency response had taken place, together with almost no change of the hf-response. The all around performance of the cabinets was immediately shifted two classes below their former state. It took not very long and I reassembled back to the solid construction already shown in my last post with the solid boards.
As next step I did dedicate my interest to the mounting of the chassis. In almost any vintage cabinet the mounting between wooden baffle and speaker is realized with double threaded nuts, which are inserted into the baffle board and take the bolts to fasten the speakers. As already said, I always find this construction a very delicate operation, in particular with full frequency radiating chassis. It is going extreme and more than delicate to mount such a 15kg chassis to a baffle board. First the simple way of a thin walled baffle, where the chassis is mounted with short wood screws. This simple way can work quite well with sealed or reflex enclosure types of smaller size. Second the way of double layered multiplex boards with 24mm thickness to form the baffle (like the 1970 diy schematics published by Tannoy) is a very difficult approach to harmonies in the response. Since the strengthened boards are always shifting the performance into a more or less edged sound with harsh ends. Additionally the chassis are fixed with inlaying nuts and solid screws tightened till the wrench brakes.
Between these two designs almost any degree of prominent resonances is possible, just the way their  physical ability to handle them will change the general property to work like a instrument.

A selection of different mounting materials, screws, bolts, nuts and wooden clamps types evaluated with this cabinets.

The older speakers from the Tannoy range even strengthen further with eight wholes instead of four. In short the massive tight construction gives way for a more technical orientated soundstage, since the opposite design opens the way for a mild more natural tonality with refined harmonies, always at the dangerous border to indifferent detail. Almost any state in-between these two positions can be achieved, depending on the character of the amplifying electronics.
In all my former evaluations with speaker cabinets I ended up with a less tight, more natural relaxed attitude of well balanced long listenability. Here now with the funnel I wanted to go a similar way, but have to find new options to realize the first path, since the funnel makes it more complicated.
My next idea was to design wooden holders which will resemble the nuts in the baffle board. For that reason I made some wooden clamps, which will press the speaker from the back side to the funnel (i.e. baffle board). This construction will have the option to adjust the tightening power precisely and distribute it by a wooden lever to the chassis. The wooden design makes a much refined transition point between speaker resonances and cabinet possible. Were the classic bolts are more or less tight or not, here a wider variation of tightness and as result of the wooden material, a improved distribution of the introduced resonances will be obtainable.

Specially designed wooden clamps to improve and control the pressure and therefore the resonance introduction coming from the chassis into the baffle.

With the clamps installed the general sound relaxes a lot, the medium frequencies get back into a perfectly refined performance and as well the hf-response improves remarkably. "…at the cost of other properties…", I did say. Yes, the lf-response suffered here, it lost precision, got wooly and overloaded in power. For the first sight it was acceptable, but I did realize immediately, it needed another idea to get all the resonances better distributed, but I had no idea yet were to search. With the building of the clamps, I did already feel like a classic instrument maker, since such introductions are "everyday bread" in this job. It looks, that it is all is a play of tightening and less tightening; to get both directions of energy into the right balance of control with contradictive effects.

I did improve the design of the clamps with the second made generation so, that they will be able to have a better distribution of energy. I did introduce the wooden dowels in order to bring the pressing right into the mounting holes of the chassis. I fixed the clamps whis double wood screws to the baffle board. With the effect, that the all around performance improved the right way, but still the named problems stayed in reduced stage. So it needed another try to get the cabinets forward to sing.
I came back to my originally used bolts and nuts. I bought rubber washers of 2mm thickness and introduces these to decouple the metal bolts from the chassis. Now everything turned back, the lf-response got bettered with fastness and tightness, the medium frequencies rounded up, but the hf-response was again a bit to prominent. Now I had the opportunity to adjust the power of tightening by turning the screws a half turn forward or back. No way, no position got out a acceptable performance, it always sounded prominent and shrill.

The perfect sounding solution, the simple and technically poor mounting with felt damped wood screws

So I made a very easy try. I did cut out washers from my 12mm felt. These got combined with iron washers and simple wood drilling screws. This sandwich got screwed tight till the felt compressed into the holes, there were four empty ones with each chassis. So I only had to remove the other bolts with rubber washers and could listen directly to the new mounting principle.

Unbelievable, a fundamental change came up. A completely improved performance of all frequencies was immediate, with a fast and airy, well extended lf-response, all other frequencies improved to a so far unknown state. A three dimensional holographic performance was suddenly present with best dynamics and a perfect sensitivity, without any particular prominence. Just homogenous refined musicality containing a wide scale of harmonies and without any offensive touch. I did listen to a lot of my analogue records this evening, as well I did stream digitally stored material from the hard drive. I did both with a good loudness (always a good sign) and completely pleasured with my new speakers. Now I need to be prevented from myself, not to change this "winning team" again. Even, when I do know that this mounting is technically a less educated solution…

The lesson from this new experience is, to take more than care about this constructive detail, if you are building a cabinet for full range speakers, in particular in the heavy weight class. The mounting of the speaker to the baffle has the same importance the materials for the enclosures itself have, as well the speaker type and finally the principle of enclosure are on par. If a felted washer can make such a difference, – a difference which in the hifi business sometimes will be paid with 1000 or more dollars (for one interconnection for example), than almost any speaker enclosure can be adjusted or improved in a fundamental state, when taking care about this detail.

If you are interested about more results from our music instrument research department read on soon,Volker

A Tannoy 15'' Enclosure for the Enthusiast – The Realisation III

                  

                  "Never change a winning team!"

Hi to everybody interested to follow on. Today I am writing from the position of complete frustration about the first audible results. Before I was absolutely save about my knowledge and new ideas which lead to the realizing of my new enclosures. As I already said, I have realized in the past several other enclosure projects for two decades, so I was absolutely safe about the most constructive details evolving with loudspeaker cabinet making. I did not expect to end my first listening evaluation last week with a complete disaster, the new enclosures did not work at all! These cabinets were not able to show any low frequency response at all. I had the impression below 300 hz all tonality has lost any lower support, below 100 hz it seemed to be like cut off. It sounded like with a low frequency control knob in contradictive position. The former evaluation cases performed very well in this discipline, otherwise I never would have been convinced to overtake the open baffle principle for the new enclosures. One more time it can be said: "never change a winning team…!"It was again one of the moments in life were I was absolutely stroked back from a unexpected effect…!

The new enclosure

For more than a half of a year I did use my former evaluation enclosures to work out almost any option for the final design. How can it be, that the perfectly made new cabinets didn't work almost in a similar way, when all constructive detail have been tested before with the dummies? All? I made some basic new experiences during the evaluation, first time in my life I did use a 15'' Tannoy Dual Concentric speaker in a open baffle cabinet. As the attentive might remember, my first impression was as well a  bit thin sound structure, which I needed to accommodate, when coming from a former reflex cabinet with big boost in the 100 hz area. After a while I learned to assess the faster, leaner and undistorted bass response of the open baffle to be superior to any other principle I had used with 15'' Tannoy speakers. With a good horn or in the open baffle the bass response can reach almost natural accuracy and timing, were other principles mostly suffer from a wooly and always slow thick bellied lf-extension, typical for ported designs. A lot of people do prefer this unnatural sound and get confused meaning the attribute of "warmth" and "rounded".

During evaluation I tested the mechanic extending of the cabinets in order to improve the lf-response with longing boards. These thin boards had been screwed to the back frame. This sort of simplest extension showed me the effect how such a extension will influence the lower frequency response. As a result I decided to built a extendable cabinet. Second I had already evaluated the front loaded horn with other cabinets and did know about its big advantage. So I have realized two wooden funnels and just screwed these in front of my evaluation cabinets. In the past I did learn to fear massive thick double walled baffle boards, they will not work well with a fullrange speaker of the heavy weight class of the Tannoy. The middle frequency response get hardened and does not sound very refined and musical. But here now the double baffle did do quite well, even when the evaluating design was almost 40mm of plywood with both layers in sandwich. I did not know why? The drivers had been mounted very tight from behind the original baffle boards, which were a solid part of the open box type construction, the funnels just added up as a additional front part.

The evaluation enclosure with double baffle boards

The implementation of this horn funnels into the  final enclosures made several changes in the construction of their mounting necessary in respect to the free sides for the sliding inside cases. At the end I did use a mitered frame design to incorporate the funnel into the housing. The completed object got screwed from the back using the strengthening frames at the front. The heavy driver is mounted directly to the end board of the funnel. Only the funnel itself supports the 10 kg of the driver and conducts as well its energy input to the whole system (resonances). My former experiences with Tannoy drivers have always made the baffle board construction, its material choice and its dimension to a delicate decision in order to find the best resonant voice for the full tonal spectrum.

Special constuction to keep the space free for the sliding cases

For two days I tried almost everything possible to make a change. I did seal the speaker to the funnel with mod rubber stripes. I did seal the interior cases with felt lips to the main frame, both in order to prevent any early unwanted shortcut of the lowest radiated waves. I did check my electronics for any defects, particular in the regulation of several power supplies (In the past a defective regulator tube did drive me crazy by its compromising sound). I did check tubes and tried very different first changes with the enclosures itself. The slideable interior frames did not show any positive effect at all (how could they do without lf-response). So I just made a quick reflex conversion, I did close and seal them and I did fill them with wool. All changes showed the same result, no low frequency response! I did run desperate not knowing what to do.

Normally driving a car for some hours is the perfect situation for me to let my brain play and find the clearest thoughts. Since I did not have any traveling at my timetable at the moment, I had to find other states of concentration. Waking up early in the morning and lying in bed is another excellent option to find deeper ideas. Here I realized some days ago, that the mechanical support of the driver, i.e. funnel might bring the problem. I did know from former realizations that the strong stiffening of an enclosure is a absolute basic to get good tight bass response. If you bring the conjuncted construction even further under tension (like instruments are made), it can even improve in this competence.
So I did know that the sliding mechanism does prevent any rigid inside constructions since its needs to keep all four side walls free of space. I decided to take the inner enclosures out and instead to introduce  massive panels to connect the holding backboard of the funnel to all sides of the cabinet. Additionally  to the precisely adjusted boards I did use wooden cotters to bring the whole construction into controlled tension and used some more massive screws to hold the boards into tight position. The revised construction has tightened up the whole design with a main attention to avoid the suspending effect of the funnel to the driver mounting. The classic knocking test with the finger at the outer case showed immediately a completely different resonant ability.

Wooden cotters bring the interconnected boards with the outer frame into controlled tension

Stiffening board underneath the backboard of the funnel

Two hours later I started again to listen to this enclosures. I remember the first moment last week. I just placed the diamond in the first groove and even without any music I did directly realize, that there was something going wrong. But now the inlet groove test sounded promising. From the first moment everything was better than right. The sound was completely different now. The tonal spectrum was very well supported with perfect balanced lower frequencies and all other frequencies seemed so much better integrated, that from the first moment on pure relaxing was on set. The lower frequencies have got fast, tight and deep, with a wonderful creaky ability to reproduce the best wooden instruments from the "Cremona School". Some records of Benjamin Britten with Rostropovich at his cello, Jaqueline du Pré and Pablo Casals made me immediately to find home in the absolute "gourmet class" of music reproduction.

But as well brass instruments did profit a lot from the improved integrity of the low frequencies. My absolutely favorite record of modal jazz music "Kind of blue" is always a very good test. A highly improved soundstage without any compression, but with extra space and air as a result of the front loading mechanism. I was sitting in front of my new speakers and more than happy with the result. Now they did match my highest expectations and they are performing even better now. They are the best Tannoy speakers I have heard till now – by far, no exception.
They have the ability to perform in the best possible manner being a true natural music instrument with well balanced harmonies as foremost attitude. They can work free of the usual compression effects and typical electrical artifacts with a wide open soundstage of almost holographic depth. Even after four hours of intensive listening no signs of tiring occurs, which is always a result of well balanced homogenous refinement. The speaker is able to produce exceptional fine micro dynamics, which is a more common character of electrostatic speaker designs, than with heavy weight champions of the paper cone class. The dynamic abilities of such drivers form the attraction to use a 15'' speaker, the combination with the refined abilities give such combinations a highly addictive dimension.

Only a handful other systems are in competition with such elaborated audio transducers. But this question is a purely theoretical one, who is able to make a direct comparison between let's say a JBL-Paragon, -Hartsfield, -Everest to Jensen Imperials, to EV-Partricians, or to Tannoy Westminsters, to  Altec's A7, to Western Electric WE15a's with WE TA7331a's or to a Klangfilm Euronor?  Nobody (I know, Dr. Takeshi Mikami, he has them all) is able to do such a comparison and I do think it is as well not necessary. It is much more on demand for the most of us, to find a good match for the own preferences and our personal taste. Mine was and is the Tannoy Dual Concentric speaker and I have realized now a longtime captured idea, to design a very good set of audio enclosures to bring them in the foremost line.

Some horn funnels on delivery in Japan

Other people would do now a recording/movie with an iphone and upload it to youtube to show the properties of the new speakers. I have never understand for what reason this little films about high end equipment are made, may be I am to old to understand?
But right now, it needs to improve the craftsmanship of the new changes in the enclosures as next step, before the last function will be implemented, the variable blinds as back of the baffle. We will see, if other unexpected things will happen?

Read on soon, Volker