TNT-Audio Readers' Corner
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March 2009

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The Big What If
Lately I've been thinking of The Big What If:
What would happen if there ever were to be a scientific basis for the things we so enthusiastically and often opinionatedly discuss, namely sound reproduction?
What would happen if you actually could scientifically produce a perfect sound system, and do it in a way that anyone could afford it?
Not just 70, 80, or 90% but so real that at least 990,000 out of a million people couldn't tell the difference at least when seated in the right spot. Exact verisimilitude.
That would certainly be a day we would all more than welcome, but what do you think it would mean:

Time to pack your bags and go home? Game over? Is it just a pipe dream or can it happen? What do you think?
I welcome your insightful thoughts.
Best Regards,
Wernher - E-mail: wernher.schaefer (at)

Dear Wernher,
first of all such a thing will never happen. Human beings were not created all equal so what might sound "perfect" to me wouldn't sound "perfect" to you. Secondly...perfect with respect to what? Reality isn't present in recordings so a live experience will always sound different from the reproduced one. Thirdly, each and any listening room sounds different...this kind of "perfect" system should be able to sound the same regardless of the listening room. Too many variables won't let this happen.
Of course we can hope this will happen in the next future...but in the emanwhile we should try to enjoy our imperfect music with our imperfect systems :-)
I, for one, consider my system "good enough". This is quite a revolutionary idea since audiophiles, normally, do not consider their systems "good enough".
Lucio Cadeddu

We'd all get on with listening to the music.
But, this will never happen, because people listen to music in different places and ways, with different ears (physical hearing capabilities, that change over a human lifespan) and different neural capacities. These physical factors are affected by health, drugs, environment, history, prior learning, etc. For a start, check out Daniel J. Levitin's "This is Your Brain on Music" (2006).
So, game on.
David Holgate

Room acoustics article
Dear Sr Cadeddu,
I am enclosing my comments to the article by Mr Wheeler about room acoustics:
I would like to congratulate you for the article published by Mr.Wheeler.
At last sanity enters the equation.although Mark is going to be a shooting target for the audio gurus (Press).

However, it should be made clear to the readers of the article, that they, gurus,are right up to a point. An acoustically balanced "listening space" is likely to 'sound ' way better than a simple space. The crucial word here is space. They design spaces not listening rooms, as Mark is quick to point out. They work with accepted theorems and absolutes, that more often than not,are just that. Most serious listeners,know, that you can't break today's accepted physics rules, but very few know that you can bend them, even without knowing how.

Lets be serious, not that we aren't:
Audio and reproduction is occult. If it wasn't, it would have been a dead art long ago. Music and audio are a kind of "mobile". Occult expresses knowledge acquired through assumptions. And like all partly grasped knowledge, we can only theorise and assume, that ,by what we think that we know, e.g "it must, be love" (nice song by the way).

You can measure what you think that you know, but what about those that you think you know, but you really don't know. Plus that the ear-brain system is a far more complicated, different and unexplored, to the limit, thing, to say at least, compared to a microphone, and an ever changing state of the art, measuring device.

For example : How our measured perfect cad x-over would react to a musical signal and not a generator tone, that is measured with a fixed imaginary impedance value (of say 8 ohms) in integrating two drivers with varying impedances (of say 6 to10 ohms) in their measurable but not active(listenable) frequency ranges? An oxymoron situation, a.k.a. the never ending circle that has no beginning and thus no end. One hops in, not knowing where it is at, starts to sing his song, and that's that.

My point is, that different listening areas, are not to be subjected to the same criteria. It is nice if you can have a well planned and executed listening room around a system that pushes the frontiers of reproduction forward. But what if a new speaker comes along,one that keeps pushing that limits further? How sure the listener is, that the room fits, still? By assumption only and after several hours of listening and adapting to the change.The myth of the so called "burn in".

Mark clearly states, that an every day living room, that you can sit in and have an intelligible conversation, is perfectly adequate for listening to quality music reproduction. And the thing is that he is right.

A symphony is composed to be played into a vast space. Berlioz made that space seem small ,and presented the listeners with a wall of sound approaching heavy metal concert levels. A small band of musicians, a quartet, will be unable to fill that space with listenable sound unless amplified. And we,listeners and audiophiles want to play ALL kinds of music in our rooms and better for it to be perfect, or else... a new amplifier awaits in the corner. Ah,and a new super woven interconnect, let alone the huge loudspeakers lurking behind the curtains. And in the end we will play with the room.

Some say that they strive for accuracy in reproduction.Others say that they prefer the outcome of a system because they like it this way, plus, plus, plus...
I tend to be closer to the second group, by the way.

We don't know accuracy because we don't know and we are unable to control every parameter of the original whole: How it was made and how it was intended to be,production wise.Therefore we have limited knowledge. Therefore we make assumptions.Therefore we have blind spots. Therefore it becomes personal preference. And no wise guys please, that they have a well known reference. It's the exception that verifies the rule. End of story

All that jazz to achieve perfection , but compared to what?
Thank you very much for the high level of your writing.
Best regards and keep it up.
Will - E-mail: sueno1924 (at)

Dear Will
Thank you very much for the kind words you say about my little window on the mythologies that surround domestic acoustics. I really enjoyed the philosophical ideas that it prompted you to share. That in turn reminded me of some of the other mythologies (entertainingly written about by Roland Barthes in the middle of the last century) that more bubbles in dish washing liquid equals more cleaning power, but we all know that detergent is nothing more than a wetting agent and the bubbles=strength is an advertising executive's mythology. We have similar mythologies in audio, more occult than science as you state. The incompleteness of the guru response is merely a reflection of our audio evolution, not a personal shortcoming; the guru is at the cutting edge but as yet that edge has not cut very deep. That we know so little makes this a very exciting field for researchers and any TNT-audio readers wondering what to pursue for their PhD should seek no further!

I would note that the occultists and alchemists were the forerunners of our own empirical scientists and in many aspects of audio research we are still at the occult stage trying to fit patterns and explanations to our primitive observations. As regular TNT-Audio readers are aware, psychological aesthetics is my main area of interest (admittedly mostly visual) and my fascination for our autonomic responses to art and music drives my hifi interest too. As we become more aware of the neuroscience of perception (increasingly resembling psychoanalytic models of these processes, but with new nomenclature) the human ability to modify incoming sensory data to fit the context becomes ever more obvious. The classic example is to walk around your house with a friend holding a conversation while recording it on a hand-held recorder. Playback, through a decent audio system, illustrates dramatic changes in vocal timbre and clarity due to the changing acoustic environments, but we just don't notice this in everyday conversation. Our brain recognises the changes in room but it prioritises intelligibility. Hence, the brain strips away superfluous data. Sadly if we suffer some autistic features or some sequelae of strokes or brain damage we might lose this ability. Then we might become overwhelmed by busy noisy situations to a hildren on the autistic spectrum experience in large classes at school).

Acoustic designers of concert halls never cease to strive to rise to the challenge of the Berlioz grandiose versus the Bach sacred in the same hall, hence efforts like the adjustable roof spaces at Birmingham Symphony Hall (the most successful of these efforts in my experience having heard both Bach & Berlioz there).

You are correct, we must remain alert to genuine references. A weekly fix of live music is essential for successful recalibration of our sensitive test equipment: EARS.
Happy listening!
Mark Wheeler

Garrard Zero 100 articles
Dear Mr. Cadeddu,
I just read a couple of your articles on the Zero 100 (I am thinking of buying a cheap Zero 92 to transfer a unique 78 (I think only one was made from the original audio of a wire recorder -- a forerunner of tape decks) to CD -- it is from a V-2 rocket launch at White Sands, New Mexico in about 1947 -- my dad was a USAF project engineer on aerodynamic heating of the missle skin).
I doubt if I want to undertake the work you describe, but I found the articles very interesting -- you are doing the LP playing community a real service. I use a couple of TD 280 Mk IV units and now have a feeling I should be doing some cleaning and lubricating (I still haven't transitioned to CDs -- you can tell how out of date I am musically!).
Best regards,
Bernard - E-mail: Skywayparkblue (at)

Dear Bernard,
thanks for the feedback! Some of the mods I suggest for the Garrard Zero 100 are very easy to apply even for the non-DIY-oriented audiophile. Give some of these a try and keep me updated!
Happy listening!
Lucio Cadeddu

Shield wire
I bought a Nuforce IA7 V1 amplifier a few days ago, and I use Supra Ply 3.4 S loudspeakers cables. These cables have a shield (extra wire) which is meant to be connected at the one end only, to groud screw or to the chassis of the amplifier, and on the other side it should be left disconnected.
Where do I connect shield wire, is it OK to connect that wire to the chassis of the amplifier or is it better not to connect that wire?
Thank you in advance,
Igor - E-mail: imartino (at)

Dear Igor, you can connect the shield wire to the black (negative) loudspeakers binding posts of your amplifier. You might also wish to experiment how the sound changes when the shield is totally disconnnected, at both ends. Difference might be subtle or non existent at all.
Hope this helped,
Lucio Cadeddu

TNT Merlino DIY mains cable
Caro amigo Lucio,
Found this on TNT-Audio, nice idea about making a DIY mains cable and just did it. Bought a 7 feet long power cord from Quail Electronics in USA and "build" my own Merlino mains cable. Using it my power amp sounds better in several areas.
Thank you very much,
Jose - E-mail: naturelsound (at)

Dear Jose,
glad to know you are enjoying our humble DIY mains cable so much. May I suggest you to try even other DIY recipes from our pages? You won't be disappointed!
Happy listening,
Lucio Cadeddu

Concrete stands
Hello! The concrete stands you used for the speakers look like your basic concrete plant stands I think. The ones I am familiar with are usually sold through garden center nurseries and are just made of concrete and no marble mixed in. I suppose they would work. I'm not sure where you put the metallic washers, underneath the base to level the stand? Anyway, sounds like a good idea.
Bob - E-mail: shareyourknowledge (at)

Dear Bob,
yes, this kind of stands is available in two different flavours: fully concrete and mixed marble powder & concrete. Garden center stores usually sell these. The one I bought didn't have a smooth floor contact area so I used steel washers to level the stands.
If you decide to give these a try, please share your findings with us, especially if you can compare them to expensive, commercial metallic stands.
Hope this helped,
Lucio Cadeddu

Still DIY speaker stands
I would just like to say that your site is a great place to get new thought's on audio gear. This past year I have been working on my McIntosh Tube/Valve Power amp's Mc30's & Pre amp C20. These units were made as far as I can tell around the late 50's. All the capacitors & out of value resistors have been replaced. The valves are around 5 years old. I found a pair of Tannoy T125 Oxford speakers, the tweeters were blown. This week I have them back from the repair shop. Assembled them back into the cabinet's as soon as I got home from work!
Oh my God the sound is wonderful. I like the music from the 50's era. So the sound is out of this world. My collection of vinyl is around 300 albums. My turntable is a Garrard 301. With a Luxman arm. Basically I bought the 301 for NZ$200.00. No arm no cabinet. So I made the cabinet. And the arm is from a Luxman turntable. It's defiantly not hi end that's for sure. But it sounds great to me.
The reason I went to your site. I am looking at speaker stands. So thank's to your site. I now have a good looking pair to make! Thank you so much for a fantastic web site!
Best Regards
Paul - E-mail: paulburton (at)

Dear Paul,
thanks for the feedback! I assume you're referring to our Stubby DIY stands. When finished drop us an e-mail to share your findings and your experience.
Congrats on the vintage system! Very nice gear.
Happy listening,
Lucio Cadeddu

Decca International Tone Arm
Can you please be so kind as to tell me from were I can buy a Decca International Tonearm for my Lenco 75 turntable. What cartridge do you recommend for use on long play records to be fitted on this tone arm?
Thank you in anticipation.
Edward - E-mail: edward.cassar (at)

Hi Edward,
I'm afraid that there is no supplier anymore. The NOS stock of these in Holland ran out a while back. I would look in the usual secondhand places, dealers, auctions, etc. Beware of people asking excessive prices for these arms!
I would use any medium compliance moving magnet cartridge (Goldring, Ortofon, Shure, etc), depending on your budget. I haven't used a moving coil one with it, but you could also try a Denon DL103.
Hope that helps,
David Holgate

Converting an older cd changer to digital output
I have an old TEAC PD1500 CD changer, the 5 disc carousel kind from about 1998 or so. It's a fine machine and in good shape, but long superceded by the better sound of my NAD 541i attached to a Zhaolu 2.5 DAC. I'd like to consider converting the TEAC to a digital RCA and TOSLINK output that could feed that outboard DAC. I'm sure there is a way to do this, but not sure without some directions if I'm yet skilled enough to do the job, though I'd like to explore doing so.
Can you give me any leads on how to do this, if it's worth doing so, and how difficult this would be?
Bart - E-mail: Bcharlow (at)

Dear Bart,
without a service manual with precise and detailed schematics it is not easy to intercept the digital flow before it gets converted by the inboard DAC. In other words, you need to pick up the digital stream right after the CD transport. My opinion is that the whole operation isn't worth the hassle. If you really need a CD changer browse the second-hand market for a used one with a digital output. These can be found for as low as 70$ on Ebay. It's a safer, quicker and wiser solution :-)
Hope this helped,
Lucio Cadeddu

Revox A78
Hello David,
I have got a wonderful amp from the 70's a Revox A78 Mk1... fabulous condition 80 watt all solid state amplifier. For an antique amp it is perfect but I am beginning to wander if I would be better off acoustically by selling this and using the funds to get something a bit more modern.
I am having huge difficulty at finding out the value of this amp and I'm a bit stuck now...
I wander if you might know roughly the value or perhaps someone who might?
I would greatly appreciate any help you can offer me.
A fellow audiophile
Will - E-mail: will (at)

Hi William
Thanks for writing. Revox is a classic brand, but I'm afraid I don't know this amp, and have never seen one up for sale. However, as there is a lively trade in paperwork relating to it you can be sure there is interest in it. So, if you stick it on eBay, say, it will sell. For how much? The frustrating answer is as much as anyone is willing to pay for it.
Have you rung one or two reputable dealers who specialise in classic hifi? They will be able to give you some indication of its value. Otherwise, you can offer it for auction with a reserve. If it is a desirable classic people will still bid, as long as the starting price is not high. If you are willing to ship it worldwide, that will widen the interest.
Your main question is: if I sell it, will I get anything better for the money? In comparison with 70s or 80s solid state, I think the answer is yes. But I am a bit prejudiced, as I prefer valves myself. However, there are some fine modern SS amps out there, as our reviews show. I'd investigate the Sugden Class A models for instance. If you are buying new, definitely try to audition first. You might find you stay with your Revox.
Hope this helps.
David Holgate

Dear William,
the A78 was/is a fairly interesting solid state amplifier, built by Revox from 1972 to 1974 and then substituted by the A78 mkII (1974-1978). It delivered 40 watts RMS per channel (on a 8 Ohm load). Today, it can be easily found on Ebay (mainly for prices that vary from 80 to 200 €, depending on version and status. To answer to your question: yes, it can still be used in a modern vintage-oriented system. Selling it and buying something new might be a wise choice if you're concerned with sound quality only. New Class-D integrated amplifiers do sound better, indeed (Trends Audio TA 10.1, Virtue.One etc.) but these are, generally, extremely minimalist (one single line input, for example). Otherwise you can browse the second-hand market for something from NAD, Rotel, Cambridge, Arcam...
Though they don't have that vintage charme they can still be a worthwhile upgrade over your A78. Actually, you should consider that a 30 years ago amplifier might need some serious internal servicing. For example, new power supply caps should be mandatory!
Hope this helped,
Lucio Cadeddu

Concordant Exquisite
I've just got my hand on a Concordant Exquisite with Exclusive PSU, both in nice condition. I would very much like to service these units before putting them in permanent use, and wonder if you have any chance to help me with circuit diagrams or for these or have knowledge about anyone who can?
Best regards,
Ole - E-mail: Olem (at)

Hi Ole,
I do not have these circuit diagrams ('schematics' to some readers). The Exquisite went through many evolutions in its lifetime, including changes to the Exquisite power supply. If you could trace the circuit and draw it for me I would be very interested to be able to give other readers access to such valuable information. I do plan to publish the circuits if we can get enough examples to decide what a representative sample looks like. The 3 Excelsiors that I know of and have obtained circuit diagrams for are all different, including changes to valve types, circuit configuration, switch configuration, power supply and even case work.
Please let me know what you can find out.
Kind regards
Mark Wheeler

Finding replacement driver for Mission 710
Dear Mark,
I read your TNT article on selecting drivers with great interest. It seemed to refer to a previous article referring to Thiele Small Parameters, but I couldn't find one.
I hope you don't mind me emailing you directly but I've tried a couple of other avenues and have come to a dead end. I posted an item on the forum about a replacement driver for a Mission 710, plus a couple of other audio forums.
So far no feed back. The thing is I'm getting desperate!

I sold up all my gear to move from Australia to UK and am sick of listening to music on a laptop, so am putting together a system on a very tight budget.
I've found a possible replacement driver on ebay but I don't know enough about the Thiele Smalls to be sure. (specs attached, item 902.426) e.g. which parameters are critical/which are flexible in finding a replacement.
I have a data sheet for what I think is the original Peerless (833737 attached)
Are you able to give me any pointers please? Being fairly new to the country I'm not sure where to go for information.
Steven - E-mail: stevenjlindsay (at)

Hi Steven
I'm afraid it probably is not worth the effort and money to repair Mission 710. I too have a pair with decaying surrounds and a blown tweeter given to me as spares or repair. They were just about okay new in their day at their price point, but nothing special, despite the hifi comics' enthusiasm for all things Mission (they were big full page advertisers). At that time they did make a good arm (774) and cartridge (the Weinz Paroc tipped high output MC 773) but that kind of sentimentality will not get you back on your audio feet after your travels.
There is no reason that you cannot get a good sound from your laptop if you use full resolution (cd red book or better) music files stored on the hard drive and output to active speakers or an amp and passive speakers. You could stuff the missions' old boxes with new drivers and crossovers from kits, but that would cost more than new speakers let alone used.

I'm afraid my article was aimed at speaker builders who are beginning to design from scratch after several successful kit projects, who would already own software for juggling T/S parameters and box sizes. You could build your own active project using a pair of T-amps and some high sensitivity full-range drivers (from companies like Fostex or some of the Chinese start-ups), or a pair of cheap power amplifiers and less sensitive full-range drivers.
A new thick baffle (18mm plywood) mounted directly over the front baffle of the Mission 710 carcass, with a single full-range 150mm or 165mm driver in each would make a sound from a laptop that would keep me entertained for a few months.
Happy experimenting
Mark Wheeler

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