Craig Sawyers
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Posts posted by Craig Sawyers
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Excellent! I have been using contacts for nearly a decade now, prefer them by a huge margin to wearing glasses.
I've worn contacts off and on for 25 years or so. But I've worn specs since I was 4, so am used to the convenience. The thing that permanently killed my enthusiam for contacts was maybe two years ago, when I was in the car and convinced that one of them was scratching. I poked and fiddled with my eyeball so much I scratched my cornea - the damned thing had actually popped out on the car floor, so it never was in my eye! Made a real pigs breakfast of my eye by poking it with my finger while driving, and that more or less did it for me. So I'm back on specs. Just another stitch in life's rich tapesty.
Life, don't talk to me about life...
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Waterfall plot, FR graph, distortion, sensitivity etc. They did test an old set so they aren't ideal but a 0.1% THD shows they did something right in 1957...
It's the wrong list, but these puppies were launched when I was one, and the pair I'm listening to right now were made when I was eight. Essentially two new treble panels (
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got my 63 back and it works perfectly. just really fantastic sound. before I had it fixed I remarked on how wonderful the bass and midrange was. now that there is no crackle I can hear how perfect the highs are. super crisp, never bright. still, I feel the most remarkable parts of the sound are the vocals and the bass. the vocals are the most lifelike I have ever heard, and the bass is loaded with layers of detail that I haven't heard in any other transducer.
I'm using my balance controls right now to match the speakers, but once I get brave enough I'll buy a soldering iron and swap the resistor on my other speaker. Kent sent me the resistor and very detailed instructions. if I can solder just a little without burning a hole through my hand I should be able to pull this off.
That it great news! Lots of listening coming up in Mobile, I suspect.
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This might belong in the Stax thread, but did you catch the newest issue of Hi-fi news? They are doing some tests on a Quad ESL as a part of their vintage roundup...
I didn't catch that - but I clearly need to get hold of a copy!
Cheers
Craig
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That's a strange design choice for sure since this line of TKD's are made for the Japanese broadcasting industry.
Yeah - I was surprised too. And suprised that being Japanese they haven't fixed it.
As for the price, a DACT should cost about the same as the TKD. I'm paying roughly 20KYen for a 4CP-2508 and a 4 gang DACT is 230$ from Justin.
I can't seem to find it now - but earlier today I found a Japanese high end retailer who had them on for 11KYen - hence my comment about cheaper. But for some inexplicable reason, it is significantly cheaper to buy a DACT from Justin, and get it shipped across the pond than it is to buy it in the UK. The damned things come from Denmark - so Denmark - US - UK is cheaper than Denmark - UK. Go figure, and good on Justin.
The four-gang DACT sits in front of me, accusing me of not getting on and populating the T2 boards.....
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Yup, same deal with the TKD as they don't have PCB terminals.
I had some problems with TKD. In fact I'm looking at the part now - 2CP-2511, a 100k stereo unit. There is no good and solid electrical connection between the metal shaft and the grounded fixing bush, so you get a really irritating whoosh or crackle as you turn the pot. I though it was faulty, so I returned it (HiFi Collective - they are a good bunch) and they cheerfully replaced it. The replacement did precisely the same thing - so it looks like a generic "feature". Just replaced it with a DACT, which is a source of joy (and a bunch more expensive than TKD).
Could certainly be overcome with a spring leaf bearing on the shaft and connected to ground - I've seen this done in Tektronix 7000 series plugins before, presumably for the same sort of reason - and there is certainly room in the T2 to fudge this in if it turns out to be a problem.
Craig
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Let's just say truvalue sold 400 lbs of lime today.
And how much tequila?
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Dragged my sad ass around a 13 mile run. Winter has come back to the UK with blizzards in Scotland. Even in the soft South I had to contend with driving sleet from time to time - so was pretty miserable and cold most of the way.
Consoled myself with a decent listening session in the evening in the dark. Pulled the piano stool in and fiddled with listening position, with good effect.
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The idea on the DACT is to make an aluminum angle bracket, and secure it to the hole provided
in the circuit board.
This all looks great Kevin - thanks for looking at this!
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/me tilts head.
I spy an LS3.
That rig must do a nice job of keeping you warm on cold evenings.
I do like the LS3 - it isn't really an Audio Research purist amp, since it is a discrete FET circuit - and it sounds really good.
The real killer for heat is the D125. There are eight 6550's in there with two upward facing fans. Quiescent power is 400W - so on a warm summer's day it can get a bit much!
I'm about to add to that thermal overload - I'm building KG's T2 clone. You'll notice that the rack is full, so I have a bit of a space crisis for that monster.
Craig
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when you were 21, transistors were easy to get :b
When I was 21, IC's were difficult to get
and the 4040 was a shiney new thing. Pass the walking frame. -
Some pics of the ShivaX2
http://www.tech-enterprise.com/tekstuff/ShivaX2a.JPG
http://www.tech-enterprise.com/tekstuff/ShivaX2b.JPG
http://www.tech-enterprise.com/tekstuff/ShivaX2c.JPG
I must admit that given the price of these beasts, I think I'll buy a second one and try two sealed box subs, and trial a dipole. That should give me an idea of which approach integrates best with the ESL57's. The wood needed is cheap by comparison.
Thinking of ESL57's, two pics
http://www.tech-enterprise.com/tekstuff/QUADa.JPG
http://www.tech-enterprise.com/tekstuff/QUADb.JPG
And two of the rig. Second one is a close up of the KG tripde E/S heaphone amp, feeding the Lamdbas on the top of the CD player.
http://www.tech-enterprise.com/tekstuff/Riga.JPG
http://www.tech-enterprise.com/tekstuff/Rigb.JPG
Craig
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Checked line by line
Forgot to mention that the checking process also found a couple of errors in my version of the BOM; I'll do another check through and then get it across to KG.
Craig
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i added an extra battery to the schematic, output a bom, multiplied everything by two
and this should be the right number of resistors and values
http://gilmore.chem.northwestern.edu/t2schem.txt
someone please verify.
Checked line by line, with minor differences on capacitors at board level:
0.47u, 12 off required - 2 extra are used on U8 decoupling both channels
0.1u, 4 off required - 2 extra used for U8 decoupling both channels
High voltage power line decoupling not on schematic (and hence not on schematic BOM printout)
But that's it. Exceptionally close. Resistors and semiconductors all A-OK.
Craig
Decoupling on
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I have a DACT in house from justin, i'll show people how to fit it in a few days.
You're the main man - hats off sir! Helluva job - how you find the time *and* hold down a 9 to 5 beats me!
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dentist
My dentist is particularly good at extractions - extracting the money from my wallet.
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T2 image - Damn, everyone beat me to it - I really really really like it, a winner!
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Very interesting! Do you think that sub will be able to keep up with the Quads though?
I can't think why not - they will take over at around 100Hz, so peak accelerations aren't so great, at least in loudspeaker terms (5g or thereabouts). The ESL itself has a fundamental bass diaphragm resonance at 40Hz or so (which is the 35 ohm peak in their impedance), so it isn't behaving ideally itself down there. The key thing is a good strong motor and a grunty amp that will put the cone where it ought to be. All the substantial 14.5kg is in magnet and support structures - the moving mass is only 200 grammes (7oz).
Gradient do a dipole sub for the ESL63 (called the SW63). That apparently uses custom 12" Peerless drivers (or Tymphany as it is now). No idea of the driver spec.
Anyway, I'm a real mug for well engineered product - and the ShivaX2 certainly is that. Exodus do even stoopider drivers, like an 21" animal called the Maelstrom at $647 a pop, with an Xmax of 32mm, a resonant frequency of 16Hz, and weighing 53lbs. But I really don't want to blow the windows out
Craig
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Thanks for clarifying.
They have reached the first 7 TeV collision!
Wow - that really is hot off the press! The first collisions were only an hour or so ago - thanks for pointing that out. At that energy, the proton mass is 7000 times its rest mass. Truly outrageous.
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Anyone want to design a logo for the T2??
Could include the head-case logo as part of it...
Include a washed bottle
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I've got interested in putting dipole subs on the ESL57's. Gradient in Finland used to do one (with 8" drivers), but no longer do. Since 1995.
The guy who has published most on dipole speakers is Siegfried Linkwitz. I've followed his thinking off and on since the late '70s. His day job before he retired was designing microwave test equipment at HP.
Anyway, his website sets out design rules. The main issue seems to be aerodynamic noise from the voicecoil cooling vents on the magnet side of the speaker. You don't hear that in a sealed box, but you do on a dipole. He kept finding speakers that were good in this respect, and then they were discontinued by whatever manufacturer. The really superb one was called the Shiva by Adire Audio. Of course Adire is defunct. Figures.
So I bought a JL Audio 12" sub for trials, and I could get no more than 6mm excursion at 35Hz before it started chuffing from the magnet side. That driver is due for the dreaded e-Bay, unless anyone in the UK wants one for a car system, or a sealed box sub for the listening room. It would be great in a sealed (or vented) box. Brand new.
It turns out though that the Shiva still exists, made by Exodus Audio and called the ShivaX2. By the time it gets from the US to the distributor in Holland, and then to me in the UK, being punished by dollar and Euro rates all the way, this beast comes in at a hefty
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All of the 63's (and the new speakers too I believe) suffer from glue issues inside the panels on top of the mylar aging (mostly because it is exposed to direct sunlight).
That figures. Perhaps that results in the film losing mechanical tension, because most of the dead ones I was looking at at One Thing had torn films - some spectaculaly so.
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Great news! I finally got off my lazy ass and shipped the speaker to Kent, whose turnaround was very fast.
Awesome! I read somewhere that owning a Quad ESL is a bit like owning a classic MG car - great to own and a pleasure to drive, but you are always tinkering under the bonnet. Certainly the case for the '57s.
The really good news is that yours have been re-panelled. I was a bit surprised on my visit to One Thing Audio how many of the '63's suffer panel damage. They rebuild the panels for 400 '63's a year, and can't keep up with demand. And that is just the UK and mainland Europe mostly.
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Had surgery today to remove a small piece of torn meniscus. All went well (according to the Doc) and my ACL was found to still be intact so no further surgery will be required. I feel like I've been roofied but otherwise pretty decent and recovery is supposed to be pretty quick.
I see a lot more biking and less running in my future.
Go easy on the recovery, and do whatever god awful exercises the physio tells you. I had a knee op three years ago, and it was scary how the leg that was op'd on lost muscle tone in spite of lots of single leg strengthening. I've got back to running, but it has been a long journey.
Folks I know who have had knee ops (and there are quite a few) either had to stop running and take up biking or swimming, or got away with it and still run. Do whatever works and have a really speedy recovery.
What did you do today?
in Off Topic
Posted
Oh yes - they are abso-fucking-lutely superb. Took my son (25) to see them in Birmingham UK last year when they were doing The Wall, and then some other stuff from UmmaGumma, Echoes, Dark Side etc to finish off. Rob has been a regular rock festival and concert goer since he was 16, and he chalked this APF gig as the best thing he had ever been to. Second row in the middle. Awesome.