Craig Sawyers

You stand a pretty good chance with Kimber - Ray Kimber was a recording engineer before he set up the company, and developed the woven speaker cable to stop thyristor light dimmer crud from getting back up the PA amps, getting into the feedback loop and then coming back down to the speakers as a buzz. He'd be pretty keen to get immunity measurements as a quantitative selling point for his cables. Cardas too, I would think, MIT, Nordost and others. Martin Colloms (HiFi Critic) has been trying to get a cables consortium together, part of the aim of which is to substantiate subjective claims with real-world measurements.

The other good idea is to route all the power cables closely together. That minimises the loop area that could inject airborne RF interference into the ground, or radiate common mode interference that is coming up the power or ground lines. Might be worth trying an air cored toroid in series with the overall ground. That way you keep the protective ground connection, but now have a high frequency block to stop utility ground shit from getting up the earth. Make a wooden donut maybe 6 inches in diameter, and wind as much heavy gauge green/yellow wire as you can around it. Wire in some very safe manner in series with the overall system ground.

Well, that sure is a pair of ebony erections

Original (low bias) SR-lambdas were the same - the baffles and electrostatic units were a single glued assembly.

Although Bob did his own attenuator using the Goldpoint roll-your-own version (and so deliberately chose 1dB per step), other commercial switched attenuators like the DACT, and attenuator transformers like Sowter http://www.sowter.co.uk/transformer-attenuators.php are available in fine step versions. The DACT fine is 0.5dB per step(!) But I'd certainly go for the more standard Goldpoint or DACT set up, with big steps for the first few, then 2dB per step thereafter. I find 2dB per step works well for me.

Boy am I feeling dumb! Been totally fooled by where the emoticons were. Then just happened to notice the smiley on the reply toolbar. Then click show all on the popup. Of course you all knew that. I can sometimes be a little slow on the uptake

Ah - there's the problem. For your preferred listening levels, and source output voltage you definitely need attenuation to centre the -12dB point of your Goldpoint. And yes, I guess that the gain of the amp could be changed. But going to say 40dB from 60dB has to done with a little care to make sure it is still stable at the lower gain, or at least has not picked up any overshoot.

FWIW the T2-clone also has a gain of 1000. My D-A has an output of 3Vrms and that puts the DACT at pretty much centre travel at the typical loud level at which I listen. Takes maybe three clicks each way to compensate for recording level differences. Half way on a DACT is -28dB, and the steps are 2dB over most of the range.

Classic! James May in a 500hp go kart that the New Stig threw around the track faster than anything else they have tested. Richard Hammond in a 1 mile race between a VW Beetle and a Turbocharged 911 - the beetle having been dropped vertically from 1 mile and falling under gravity. Oh yes!!

Just latching onto this thread - but if your friend can phone international call Russ Andrews. They recable K701's with Kimber stuff. I have a pair with that cabling - and they do it themselves. Phone them on +44 1539 797302 which is John Armer's personal line and mention my name - I'm sure that they will tell you the secret methods of disassembling the beast.

No - they are precisely the same as in your photos - absolutely no closure of the vent. Now, courtesy of your blu-tak idea, they have exactly the same sound as the Lambdas when you push the cans closer to your ears (what you describe as squeak/fart).

Yes - SZ3-1487. What is the relevance of that? And what am I missing with earpad height? Yeah - I know you're going to say it is already in this thread somewhere

I'll have to have a browse though those - looks good. And sorry to be a smart ass (well, not sorry at all really) but I looked it up and - I was right. CMB at 160.4GHz

Much more solid and tactile low and mid bass. Kick drum really kicks now. But it goes beyond that - the whole voice thing sounds cleaner in some way too. Maybe there is a helmholtz thing going on between the large void between the ear and the diaphragm, and the little (leaky) void that colours the midrange in some way.

Um - blackbody radiation with a peak at 160GHz. Cosmic microwave background?

Had a real panic yesterday. Took the SR007's apart to do the blu-tak port mod. Got them back together and plugged them into the T2 - bad distortion on RHC. Serious panic sets in. Turned out to be a dead 2SJ79 that was causing one output to be at -250V. Just blew coincidentally with the blu-tak mod. The astonishing thing is that with a dead driver transistor for the grounded grid output EL34, the damned amp was still working - all that happened was that the output clipped and distorted - and of course the headphone diaphragm was biassed one way. J79 replaced and all is sweetness and light again.

Interesting. Distortion on right channel, at high-ish listening levels. Well actually very high levels. Got it on the bench - One of the RHC outputs was sitting at -250V. Took about three minutes (after the endless fixing screws had been extracted) to find a dead J79. I suspect that it must have been weakened as a result of the earlier C3675 saga. Anyway, all sorted now. Just reset the batteries, and button it up again.

Have a great one Mike!

Snakes in a pool.

Well, that depends on the money. If you pay relatively little, you will have to spend some money fixing them. If you buy a pair that has been restored, you will pay much more. I bought mine for £300 and then spent another £250 and a lot of time to bring them completely up to original specification. Bear in mind that these are very old loudspeakers, and like a classic Ferrari need restoration and TLC. Mine are 1964 built.

Indeed - the ESL57 has a horrid impedance curve - with a big 35 ohm peak at around 70Hz and then falling to less than 2 ohms at 20kHz. It seems that tubed amps (which is all there were when the speaker was launched) cope with this better than semiconductor ones, which can sometimes run into current limiting and self oscillation. The idea of damping factor, which is important with coned loudspeakers to control their motion, is not really relevant to electrostatics (where the moving mass is only a few milligrams) - so the much higher output impedance of tubed amps is not a disadvantage. FWIW I use a second hand Audio Research D125 to drive mine, set to the 8-ohm taps.

It is the ESL57, of which I own a pair. If they have not been reconditioned, the main problems are: 1. Burnt out mid/treble panel 2. Defective voltage multiplier 3. Leaky bass panels 4. Resistors and capacitors in the crossover wildly out of tolerance But spare parts and reconditioned panels are easy to get - I used http://www.onethingaudio.net/ for mine, which is an hour drive from where I live. Two mid/treble panels, bass panel dust cover kit, mid/treble protection kit (to stop the new ones burning out!), new internal wiring and a kit of components for the crossover. Stunning - there are things the '57 does that no other speaker does - particularly voice.

I'd certainly be interested in such a trial. The perception is that the difference between a Russ Andrews/Ray Kinber power cable and a regular kettle lead IEC is remarkable and non-subtle. The same is probably true of other cables based on more than smoke and mirrors, like Cardas. If that perception (and by implication the 97% who keep these expensive cables and don't return them in the 60 day trial period) is correct, it should be possible to hear by doing a high quality comparison. I might weill set up a simple test using a pair of high current relays, arranged so that the cables are paralleled for a fraction of a second so that there is no perceptible changeover click. If I get around to this, I'll post a few first impressions. But alas this is not the game the Advertising Standards Authority play. And they are immeasurably more used to ruling on a second hand car dealer who is misrepresenting his wares.

Did 5 miles in studded fell shoes on a very boggy section of the Ridgeway.

It certainly does require a significant time committment, and very careful set up and analysis. Listener fatique and the skew that this introduces into the statistics has to be taken into account. We used ABX testing during loudpeaker development when I was CTO of Wharfedale, with an acoustically transparent curtain between the listeners and the speakers, so I'm certainly not against the technique. But the ASA case has nothing to do with being able to tell what the subjective differences, or otherwise, are. You have to look at the ASA website - an ABX test would simply be an "opinion" and hence not "robust" evidence - their italics. Russ Andrews promotional materials were judged to breach CAP code 3.1: "Before distributing or submitting a marketing communication for publication, marketers must hold documentary evidence to prove all claims, whether direct or implied, that are capable of objective substantiation." and CAP code 7.1 "No marketing communication should mislead, or be likely to mislead, by inaccuracy, ambiguity, exaggeration, omission or otherwise." The only response to which is hard technical measurements - their case is down to objectivity, not subjectivity. I really don't want to get into a tussle about this, because that is a no-win situation all round. But to put the data here, this a typical graph of rf attenuation (well it not technically attenuation - what does not get through is reflected) vs frequency.