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April 2010 issue
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Old or out of date things are not necessarily in truth out of date!
If we look at the things that are new, is there a set limit before they become old? A brand new out of the box PC is almost instantly old as soon as it’s open.

Lets take a few things that are significantly older than vinyl LP yet are not looked at in this way. The Pneumatic tyre is older than vinyl LP yet we still use them on almost all motor vehicles. If we look at the house we live in, they use stone or brick walls with wooden floors and tiled roofs, as in Roman times!

If we look at modern materials like Titanium, the fourth most abundant metal on this planet, how old is Titanium? We can go back to the Big Bang!
Those who can’t stand the few clicks and pops from vinyl should just think the next time they’re driving their expensive cars playing beautiful music, how much road noise will they accept?

Most musical instruments work on vibration, vibration of the materials as in such musical instruments as guitars, violins, drums etc.
It is my view that we have all been the subject of such pernicious mendacity, we’d believe in nothing other than digits, we all know who invented numbers, numbers certainly were not around before humans were on this planet.
If we have 13mm of copper there are approximately enough atoms for each human alive to have 15000 000 000 atoms each and that’s only 13mm of one material!

For me, when I put an LP on a good record player I’m not counting how many numbers it took to make the music work, I just put on an LP record and enjoy.

Analogue in all it’s forms and including the vinyl LP is here to stay? Because numbers don’t make music, people do with their voices. instruments, timing, humor etc.
many thanks
Jeremy Ridsdill
Weston Super Mare,


As someone, admittedly, “obsessed” with collecting vintage hi-fi (though, that mainly depends on looking for non-working equipment which can be had for a “steal-of-a-deal” at either charity stores or house auctions), the “Olde Worlde” segment is of particular interest to me. It prompted me to want to share a photo and background info on three 30+ year-old components I’ve rebuilt and use [almost] daily.

The amp: Sansui 70 watt-per-channel, solid-state stereo receiver (model 4000) from 1970. I bought this at a charity shop for $20 U.S. It was a rare to find one with the then-optional wooden cabinet still on it - and even an envelope containing the schematic diagram stuck underneath. All the caps in the preamplifier stage I’ve replaced with 1% tolerance, metal polypropylene-type (for the high frequencies) and all tantalum-type for the rest (though, for the power section, I did use Cornell Dubilier high ripple electrolytics).

I also replaced all of the point-to-point connections with at least 16AWG automotive-grade primary copper wire (I’ve figured out that much of the reason even decent built 1970s-era kit sounds crummy was because they all used cheap, 24AWG aluminum wire for internal connections ... which does not take solder well and just seems to disintegrate over time. I replaced the power cord with a three-prong, 14AWG grounded one and in the future I plan to replace all the input/ EQ stage resistors with VISHAY 1%, 1/2 watt metal film-type.



Sansui 4000 receiver from 1970 and Ampex tape deck from 1966, both restored, are used by James Hoover in New Jersey.

The tape deck is Ampex stereo, auto reverse, solid-state reel-to-reel recorder (model 900) from 1966. I got this at an antique radio fair for $10 U.S.  Ampex was the name in high-end (American) analog recording equipment (like Studer/Revox was in Europe) from 1947 to 1984. Now, my machine is a far-cry from the 10 1/2 reel studio units they specialized in; but, none the less, anything made by them is hard to find. Japanese brands dominated the tape recorder market after 1968. I’ve learned that this model was/is supposed to be a “portable” (but it weighs 40 lbs!) and it was originally priced at $349.95 (in 1966 American dollars). Again, like the Sansui, I replaced all the capacitors in the preamplifier and power supply sections; as well as a belt for the [dual] capstan idlers – the main problem with it in the first place. I play the 50 or so pre-recorded tapes (of Sixties albums and film soundtracks) my father left me. He had the reel format version of the Sergio Mendes/Brasil ‘66 record you have on the Beocenter combo unit. I love that late ’60s Bossa Nova and even Herb Alpert’s stuff ... I’ve got every album of his Tijuana Brass on open-reel!

The turntable: Technics Direct-Drive (model SL-1700) “disco” turntable from 1977. I bought this at the same charity shop, for $25 U.S., I’d later get the Sansui from. This, save for the cartridge and stylus, was in the best overall condition out of the three. I once found a new-old-stock supply of bargain Empire MM cartridges so I just replaced the damaged Shure M91 already on it (I’m not particular about needing some esoteric, MC cartridge because I consider the vintage tape as my main source). The only “tweaking” I’ve done is that I took the bottom off to unsolder the standard patch cables and replace them with a spare pair of Monster ones I cut up.

The 'speakers are the only “new” thing in my system: a pair of mid-nineties JBL LX500, three-way, bookshelf-type.
I like the fact your reviewers seem to concentrate more on describing the build quality of a component and how it, actually, “performs” a piece of music. A lot of other critics just tend to gloat about their record collection or how they have connections with “insiders” (whom they’re probably trying to get free equipment from).

I mean, everyone is talking-up Ken Ishiwata’s 30th year with Marantz; however, does anyone remember that they’d gone really downhill in the 1980s? It wasn’t until Philips invested into them in 1991 that they, again, started making quality consumer gear (a lot of Marantz stuff from the ‘80s had a gold-painted, plastic fascia with a cardboard masonite pan!).
James Hoover
New Jersey,


I have been a reader of your excellent magazine since the early nineties when I moved to London, and it was at this time that my interest in hi-fi also started.

Here in Ireland there were no proper hi-fi shops, and coupled with the fact that I was broke most of the time, were it not for the move to London, it was an interest and hobby that might never have happened.

It was strange, how walking into a proper hi-fi shop on Buckingham Palace road in 1990 had me feeling like a kid in a sweet shop. I wanted to listen to everything that they had, in every combination, despite the fact that I couldn’t afford most of it. The owner played me a piece of piano music on a turntable through a pair of Castle Chester speakers, and that was it, I was hooked. I thought it was the most incredible thing I had ever heard.
There is just something about walking into a store like that and seeing all the amps, turntables, CD players and speakers that has me wishing I owned a place like that. I would probably end up being my own best customer!

Back in the real world though, I decided on a pair of Castle Warwick speakers with a little JVC CD player and a Creek 4140 amp, and so the hi-fi hobby began.

I didn’t go crazy with constant upgrades, and I can tell you that had more to do with financial constraints than anything else. I kept the components for two or three years and upgraded slowly.

It was the mid nineties when I started to get serious, and following the purchase of a new Linn Karik 3 to match the Wakonda and LK100 I had bought some months earlier, I realised that my speakers, which were now B&W P4s, were not delivering the goods. What to do, I wondered?
As luck would have it, I bought Hi-Fi World that month as usual, and it had a World Design Supplement for a pair of DIY speakers called the KLS6. Hmm, they look interesting, I thought, but I wondered how could they possibly match a commercial speaker; given all the resources available to a commercial manufacturer, it wasn’t possible. Wouldn’t everyone be building “these DIY designs” if that was the case, or so I thought – little did I know.
It was mentioned in the magazine that the 'speakers would be on display at the upcoming hi-fi show in London, so I made a mental note to go and see them.  Time passed and one Saturday I found myself strolling the corridors of the hotel in Marble Arch, going from one room to the next, listening to all the demos, but sadly nothing I had heard all day stirred my desire to spend money, at least not on 'speakers anyway.

By the time the show had come around I had completely forgotten about the KLS6s, but here is the strange thing. I was walking down one of the corridors on the way out of the hotel feeling disappointed that I hadn’t discovered what I wanted when I passed this room with some music playing.
It was a female vocalist singing a jazz number; well the sound stopped me dead in my tracks. It sounded like she was in the room, which was so jam packed with eager listeners I couldn’t even see what was producing this wonderful sound.

At the end of the session half of them left, so I squeezed in and grabbed a chair for the next demo.  And then it hit me, I thought: those speakers look familiar, where have I seen these before? I couldn’t believe it. Quite by accident I had stumbled into the KLS6 demo, and I thought this is unbelievable.
I had been walking around all day looking at 'speakers, going from one room to the next listening to boxes costing from a few hundred to tens of thousands and nothing moved me, well at least nothing that I could afford anyway. And here I was listening to a pair of DIY speakers and I could barely contain my excitement.

I was absolutely captivated by them, and within two minutes I had decided I was going to build a pair, and I did. I remember driving to your workshop in the basement of some building, and collecting all the components, I can’t even remember where it was, and two weeks later I had a pair built.
When they were run in, I can’t tell you how proud I was.    I had built a pair of speakers for a £1000 that could beat the socks of many a commercial design costing four or five times as much, and the sound with the Linn gear was amazing; it was everything I ever wanted and more.
In 2000 I moved back to Ireland, and three years ago I was fortunate enough to be able to buy a detached house, something I always wanted, and in music listening terms those three years were the best ever. I could play my music to suit myself, and not my neighbours.
I recently managed to buy a Linn Kairn and Klout on e-bay, and now that the Karik has the amp. partners it was designed for, the whole system is just magic.

All I need now is a Numerik DAC to top it all off. I know, fourteen years after buying the Karik, as you can see I don’t rush things.
To this day I have never felt the need to replace the KLS6s, and probably never will, except for one problem; yes you guessed it, the tweeters. The gas has leaked, and they are not giving their best, the question is what do I do?

As you know those Audax tweeters are impossible to get, and as I see it, the only option is to replace them with a different tweeter.
I know that Peter Comeau did an article last year on replacing the same tweeter in the KLS3 with the Seas Millennium. Was anything like this ever done for the KLS6? I have to admit I don’t always manage to get the magazine every month and I could have missed it, and there is nothing on the forums about the KLS6.

It is strange that it is the one design that is never mentioned. I have considered buying the equipment to test the new driver myself, and using lspcad to design the crossovers, but this is unknown territory for me, and I wouldn’t be at all confident of success.
I have even considered replacing them with a commercial design, the Monitor Audio PL200s look good. How do you think they would compare sound wise? I suspect myself, more bass, and maybe less detail and transparency.

All things considered I would much rather do something with the KLS6s and I am open to suggestions no matter how crazy. I just want my KLS6s back to good health.
Any ideas guys, help.
John Egan.


The World Audio Design KLS6 loudspeaker, with Audax High Definition Aerogel drive units and Audax HD-3P Gold Dome piezo, gas filled tweeter.

Hi John.  What a heartening tale!  The article you missed was in our June 2008 issue, on p80. Unfortunately, this detailed how to substitute a SEAS Millennium for the Audax HD-3P Gold Dome in KLS3, where it crossed over to an Audax HM130CO 5in carbon fibre bass/midrange unit. In KLS6 we used Audax High Definition Aerogel units (DIY Supplement No16, August 1995), the midrange being an HM100ZO.  I suggest you use the SEAS Millennium tweeter and the high pass section feeding it, shown again here. The low pass feeding the midrange unit of KLS6 reached higher than that of KLS3 and the match is unlikely to be perfect. It is difficult to predict the result, but there is a likelihood of excessive treble. If this is the case, best to try reducing the 4.7uF capacitor to 3.3uF or so, and altering the resistor in front of it, in the range 0.47 -1 Ohm. It isn't possible to sort out a perfect match without measuring equipment and lspcad will not on its own be sufficient. A measuring microphone is the crucial requirement and Clio make an inexpensive one (£220), but it needs a preamp. This would then run into a computer sound card or audio input. It is then possible to play white noise from the computer, through the speakers and run spectrum analysis of the signal on a computer, using free Audacity software. Audacity will generate white noise and spectrum analyse it. It isn't too difficult or expensive nowadays to make this sort of measurement to a useful degree of accuracy. You need to get into the right ball park, as it were, then fine tune by ear.


Audax HD-3P piezo Gold Dome tweeter (with crossover), filled with gas. Highly expensive and leaky, but sounded fabulous!

I'm glad you like KLS6. It used super high quality Audax drive units and we tried to get maximum midband transparency by using an open back midrange. Sadly, there is no equivalent to the (hugely expensive) Audax HD-3P piezo Gold Dome tweeter. Modern ribbons are less forgiving in their sound. You will not find Monitor Audio PL200s have the same tonal balance as KLS6 (we designed for accuracy; our loudspeakers did not have to compete in a showroom) nor the lack of tonal colour exhibited by the KLS6 High Definition Aerogel midrange unit. So you should try and keep them running if possible. I'm glad they have provided so much pleasure over the years. NK


A high pass filter section for the SEAS Millenium tweeter, when used in KLS6. Values will need adjustment.


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