Craig Sawyers

Shit. Apart from the MPSW transistors we're talking about here, ONsemi were one of the major suppliers of TO92 packaged transistors. It does make you wonder whether they engineered the disagreement with their packagers because of a strategic decision to move to SM

More background, after Magnets Bulbs and Batteries. I got interested in audio at about age 15 or so, having been given a record player at age 13 (with vinyl-clashing autochanger) and was not that satisfied with it. Not having much money, I walked into J G Windows music and hifi store in Newcastle on Tyne (UK) and asked if they had any Saturday jobs. Still there, and doing the same sort of stuff http://www.jgwindows.com/pages/Contact-Newcastle.html. It turned out yes they did have a place for a Saturday lad, so I got my very first paid job in 1972 (oddly enough the same year that NAD - New Acoustic Dimension started in business), My job was selling hifi gear, which I was not too shabby at. But the really big advantage was that I could buy anything in the shop at cost price - so a third off. Hifi gear, records, televisions, musical instruments. It was at that time I bought my Thorens TD150 (still have it, 42 years on) and SME 3009 pickup arm (still have it). Bought lots of records, from Classical to heavy metal and everything between. I built my own amp and speakers. That rig went through my entire university life with me and did not miss a beat. But in my first year, I was in digs (ie living in someone elses house for money) and thought I'd better get a pair of headphones, and found a pair of Koss PRO4AA second hand in a local shop (now in Southampton). They were very good, with fluid filled ear pads - but they were crushingly heavy and it felt like you head was in a vice. Eventually I upgraded to a (second hand) pair of Koss ESP6 electrostatics. They were a real revelation in clarity, but boy oh boy were they heavy. The HV and step up transformers were in the earcups, and fluid filled ear pads again - you needed total dedication to wear them. I went through several different loudspeaker/amp combinations, going active at one stage with the first of Linkwitz's designs, but using transmission line bass units - this in 1978-ish. But my move to high-end came at an audio show in London (the Heathrow Penta show) in maybe 1985. I walked into the Meridian room - and Meridian at that time were importers of Mark Levinson. So they had their CD player into a dual mono ML with external power supply, into ML class A monoblocks and Quad ESL63's on stands. They were playing Brothers in Arms, something I knew very well. It sounded like a completely different piece of music! At the time I was using the first generation Philips CD player, the TD150 etc into a Quad 34 pre and 405 power amp and a pair of KEF speakers - but the Meridian room totally and utterly demolished it sonically. I just HAD to have something that came close. So I've been though Krell, Audio Research, Magnaplanar, Martin Logan, Podium, Quad ESL57 over the years, and have now settled on homebrew power amps (8 channels) and active LX521's - by Linwitz. And there it is going to stay apart from inevitable tweaks for a good long time (knock on wood!).

This community amazes me. The USSR and now India!

<breathless>

Real bacon from a pig, and real turkey together in a sandwich is a fine thing. But TurkeyBacon

Well thread this is a new discovery! I've gone back to fundamentals to an extent over the last year. I too use Sandalwood soap (Mrs S likes the smell, and who am I to deny her?), the soap block not the cream. One block lasts about a year. I buy my stuff from this outfit http://www.theenglishshavingcompany.com/any/Edwin-Jagger/. Silver tipped badger brush. Although I use one of their shaving blade handles, it is one that takes Gillette Mach3 refills. Like this Never ever have a rash, and almost never have a cut (and that is only when I lose concentration.

Good god it eats engines too.

At the back end of last year I was on business in the United Arab Emirates, in Abu Dhabi. You could not get real bacon at breakfast (a Muslim thing regarding the pig), and only Turkey Bacon was available. It was I am afraid totally awful, tasteless stuff with the consistency of slices of paste. It was so awful that I defaulted to having a can of beer nuts from the room for breakfast instead.

Ah - the Mercury Living Presence recording. Antal Dorati conducting the London Symphony Orchestra. Still awesome even now (I have the CD, not the black vinyl). Sleeve notes say it was two 6lb smooth bore bronze cannons and a 12lb Howizer, from West Point, and fired under the direction of Gerald C Stone by the reactivated Civil War Unit, Battery B, 2nd New Jersey light artillery. The CD has a demo of the recording technique with a voiceover. So yes, real audiophile cannons for sure!

Ah - goddit now

Um - interesting. I took Oz in his profile as the short form for Australia! If he is in Texas, there are far more auditioning options.

Have a look at the website devoted to builders of Linkwitz's designs http://orion.quicksytes.com/. There is a thread devoted to finding people who have built the thing and are prepared to invite others to have a listen. Now you're in Oz, which is a big place (32 times the area of the UK, and bigger than the US if you leave off Alaska), so finding a builder withing striking distance might be tricky. Aha - there is someone in Adelaide with LX521 http://orion.quicksytes.com/viewtopic.php?f=28&t=2787 But the latest design is called the LX-Mini, is built from bits of drainpipe (I kid you not) and all in - drivers, DSP crossover, power amps etc - should cost under a grand (Euros or UK pounds). In fact a kit (minus DSP and power amps) is available from http://www.magiclx521.com/news.htmlfor Euro 499 plus Euro 78 shipping to Australia *including* the drivers. When the Mini and the LX521 have been reviewed at audio shows, the Mini has all the sonic characteristics of the LX521 but with less bass. When you consider the price is about a quarter of an LX521 system it is so worth a punt The *drivers* for the LX521 cost more than a complete LX mini system!

You must've filled up his senses, Tice

This is a news story even in the UK - so it looks like a big one. Stay safe if you are in the path of the blizzard coming in.

Thanks for the kind comments folks! The good news is that it passed the wife test. That she likes the look of these is more a statement of what outrageous speakers I've inflicted on her over the years. But even better she is blown away, in her own terms, by the sound quality "It sounds so involving - you just get drawn into the music". If it had sounded like a bag of hammers she'd certainly have said so . I remember a couple of years ago I hauled her along to an audio show in London - a showcase for British high end. Anyway, we walked into some room or other, and they were playing a Marc Cohn track that we know very well. I did sound absolutely dire (a mate describes that effect as being like having the back of your eyeballs scratched), but Carole started to laugh out loud - I had to shoo her out with the comment that the guys in the room had actually worked very hard to design a product that sounded so awful, and were cloth eared enough not to notice, and you had to respect that particular talent with quiet decorum.

Got the LX521's fired up. Apart from a temporary hum problem, everything connected up and worked right off. I honestly have heard nothing remotely like them. The first thing that hits you is the imaging (or "phantom acoustic scene" as Linkwitz terms it). They are twitchy regarding positioning - I was underwhelmed first off until I used a tape measure to set them equally from side and end wall, and then frigged a little with toe in. At which point I've spent 4 hours having my socks blown off. They are punishingly neutral, to the extent that truly great recordings sound awesome, and ones that are poorly recorded sound desperately bad - like having a camera into the the head and stone deafness of the recording engineer. Mind you, I overdid the amp heatsinks - they got slightly tepid after four hours solid at pretty high listening levels. All interconnections are balanced, and colour coded throughout to prevent something dumb (like putting the bass output through the tweeter). Amp to speakers is an 8-pole speakon, for the same reasons - regular speaker connectors offer too many possibilities for getting it wrong.

Aagh - what a nightmare, Peter. Fingers well and truly crossed for insurance stepping up to the plate

Ah yes - Clive Sinclair. Back in the day (late 60's early 70's) and always trying to minimise costs he would acquire hundreds of thousands of reject transistors free. His team would then test every one to find the few that actually worked OK to use in his products. The reject transistors were used in the foundation for his driveway.

I guess there was a moment for all of us that got us interested in audio, electronics, science and so forth. To kick things off, this was got me going. In the UK during the 60's and 70's there was a series of educational books for children called the Ladybird books. It eventually ran to hundreds of topics, but were written in very clear language and with superb illustrations. It shows what an effect this had on me - I remember precisely the book - Magnets, Bulbs and Batteries. And thanks to the web, here it is www.vintage-radio.info/download.php?id=358 vintage 1962. I remember pretty much everything I built from that - and from the publication date I must have been 7 or 8. The one I remember particularly was the electric motor made with a cork, some needles and pins, a few paper clips and wire, and a battery. The only bit I needed help with was pushing the needle through the cork, but only because I did not have the strength. So what moment got you interested?

I'm replacing Quad ESL 57's equipped with my own dipole subs, so I have a known and very neutral reference with which to compare. The main problem with the ESL's is that to image properly needs very careful set up, and a sweet spot that needs your head fixed in a vice (or vise depending on the side of the pond). I seem to be making a habit of dipoles - going back from the Quads, Podum 1, Martin Logan something, Magneplanar something. Mind you I have heard some spectacular box loudspeakers (the best was the Rockport Arrakis) in the airy price stratosphere, and way out of my pay grade.

They look really interesting modules; loooong thread though, 127 pages in about a year. Self is not without his quirks - he is very anti FET and anti AB - although the performance figures of the current modules in your link have superb performance. Don't underestimate the influence of power supply wiring - the half wave rectified currents in +/- power supply leads to the amp can induce significant excess distortion.

Yeah flat pack would help. But not for me - I started with two 8 x 4 sheets of marine ply and did it from first principles. I've gone for Douglas Self blameless. Each bass driver gets a load-invariant amp (four in all) with a measured output of 175W at 4 ohms each. Mids and highs get a compact blameless, which still does 175W into 4 ohms, but with more distortion that the load invariant. They are all Class B. Measured distortion at 50W 8ohms, 80kHz bandwidth and RMS sensing is 1kHz 0.0028% 10kHz 0.0040% 20kHz 0.0056% But the residual distortion of my set up is 0.0027%, so the actual harmonic distortion is pretty insignificant. In hindsight I might have gone for his "trimodal" design. That has a switch to select either Class B, or Class A/AB. In A/AB mode it does 30W class A and then changes to AB from 30W to 100W. So easily switched to Class A/AB for the tweeters.

I'll be able to tell you in a week or less - just finishing the second four-channel power amp; final wiring underway. I can tell you that they are not a project to be undertaken lightly - it is an expensive and complex project. Drive units are nearly a grand (in UK pounds) alone $1600 in the US. The bass units are the most expensive of the drivers, because they were made to Linkwitz's spec. The woodwork is complex, but flat-pack kits are available from Madisound in the US https://www.madisoundspeakerstore.com/cabinets/lx521-linkwitz-lab-flat-pack-cabinets-%E2%80%93-pair/ and http://www.magiclx521.com/lx521-components.html in Europe.

The original SRM-T2 had many of the active devices mounted on isolated heatsinks

Dunno why the pics are dead. Attached below. I *think* the one on the right was the fake. Breakdown voltage was far too low - heaven knows what POS silicon is actually in the package.