Craig Sawyers

Happy birthday!

Woah - how did I miss this! Very happy belated, Justin!!

I've only had one root canal done. I'm not nervous about dental work, and wasn't for this either. But three two hour sessions in the chair was pretty full on. The first session was emergency work to stabilize it and shove some sort of disinfectant in there. It will improve Fitz, and the feeling of having your jaw feel as it has been kicked by a horse will quickly go. I honestly have lost track of the number of crowns I've now got.

I had to click the link. I saw Northampton and thought it was the original one (this is a nice bit; there are bits that aren't so nice!). But it sounds like an amazing day at the US one.

Sennheiser used to be great with spare parts. My original DT990's were just starting to wear out. Senn supplied new stirrups (a pin had broken) ear pads and leather inner strap. About three or four years ago.

An impossibility surely (And don't call me Shirley...)

Interestingly the data sheet is inconsistent. It says 20AWG and 0.05mm^s in the title block, but 0.5mm^2 in the main drawing (which is the correct number) Anyway, assuming it is 0.5mm^2, that is 0.033 ohms per metre or 0.066 ohms loop resistance assuming 1m long umbilicals. The output tube pair takes 0.9A, so the voltage drop along the wires will be 0.9 x 0.066 = 0.06V. So that wire looks just fine ================================= Correction Wrong current! I looked up 6AC7 rather than 6CA7. Correct current per pair is 3A. So the voltage drop is 3 x 0.066 = 0.2V, which is a bit more significant.

Yes - I use the same PTFE coated wire, 600V rated. So from one conductor to another it should be 1200V. The maximum difference is from -500V to +500V - so 1000V. In fact it is a bit more, because there is a -560V line, so 1060V. Now in all likelihood the insulation will be OK. But I decided to double insulate the heater wires at -500V just to be sure. But hey guys - just telling you what I did with mine. Whatever works for you is OK with me.

They have replaced the UT513 with the UT513A. But it seems to be a bolted on bargain - in the UK £227. And unusually for a Chinese product the CE mark conforms to the correct logo, so it looks as if it was properly certified. Thanks for the heads up! I regularly use an AVO RM290 Megohmmeter, but that only goes up to 1kV, but it does go to 10^12 ohms. Good old analog meter.

Provided the insulation between the 6.3V that floats at -500V and the line at +500V, fine. If there is a chance that the wire insulation cannot handle 1000V difference, you are going to need some sort of additional barrier. Hence the fiberglass sleeving over the twisted and floating 6.3V.

I have no idea where my fiberglass sleeving came from - but it was almost certainly Farnell or RS. Mine is black. I'd have to root around at the back of my rig to measure precisely how long my umbilicals are - but three or four feet, no more than that.

Umbilicals - takes more time than you might think! IIRC mine took a solid 8 hours plus. Because the heater feeds to the power tubes float at -500V I ran the wires inside an insulating sleeve in the umbilical. Glass fiber I think... Well done with the fault diagnosis BTW - nice job!

One of the best albums ever recorded. I have it on vinyl, twice (old original and new 180g reissue), on CD and ripped to NAS, and on Tidal HiFi. Recorded the same year as Carol King Tapestry.

Well I wouldn't even try. But then I'm a stickler for doing things by the manual, and believe in the maxim RTFM. I think that doing inter-comparisons between bits of circuit is likely to confuse rather than illuminate. The best way to test the circuit is to run it and very carefully measure voltages (because they are high, and deliver substantial currents) and compare with what is expected. Just don't slip with a probe, because it might spoil your day. To keep from generating frightening sparks and dead silicon, I have often soldered on stiff short lengths of wire as temporary test points and use those to clip to. Once the fault is diagnosed, they can be desoldered.

You can't use a Peak DCA75 to test in-circuit. It says so in the manual.

Have a great one! Happy birthday!

One of the reasons that Assange holed up in the Ecuador embassy in London was he was facing charges for rape in Sweden. And of course extradition to the USA. Although rape is an awful crime, there was something about the Swedish case that did not quite sound right, and if one was cynical it was all part of an extradition attempt. In due course, the rape charge was dropped because the case against him, according to the Swedish prosecutor, was "weak". There is a continuing attempt to extradite him, which keeps being blocked by UK courts. He is currently being held in Belmarsh prison without bail (on remand, before trial), because he is a flight risk. He is in prison because he breached the terms of his original bail, and holed up in the Ecuador embassy. Mexico has offered him asylum. The whole Assange thing is very strange, and in spite of Chelsea Manning's sentence being commuted by Obama, her legal position is still fragile.

Guns, flak jackets - icecream. How British!

A couple of years ago my wife went in for wrist surgery, and while we waited a guy in his early 20s was waiting for the next surgery in a journey as a result of a MB accident. Downhill into a dip, came off, and noticed one foot was rotated by 180 degrees. Compound fracture with bones sticking out. Fortunately he had a phone and enough signal to call for help. Helicopter extraction. First surgery was 8 hours. Next one was 8 hours. Etc. Weeks in hospital. I have no idea if he was wearing a helmet.

I saw Apogee and immediately thought But then I clicked the link, and it wasn't *that* Apogee! Equally interesting though.

Oh for that much space! super-jealous! My bench, bandsaw, jointer/planer, router table and radial arm saw are squeezed into a single width garage. It needs real discipline to use every machine safely.

Good luck sourcing KSA1156 unless you have some already lurking. Looks like various dates in 2022 for next delivery.

ML Aerius. I had a pair of those. The electrostatic panel disconnected itself on both. I contacted ML, who said if I was in the US they could supply new panels cheaply (ish), but because I was in the UK I'd have to go through Absolute Sounds who had a vicious mark up. So I popped the wooden side panels off, fed small pieces of antistatic foam in each hole, and trapped a connection wire under some kapton tape. Soldered the wire into the HV feed. Put the wooden panels back on. Problem sorted, and totally invisible. I later sold them on eBay, and made it clear that the panel had been repaired and how. I got a good price; the buyer collected and I demonstrated them working before he took them.

You think Mouser's lead time is long? R/S is June 22 and Farnell is August 22

Sourcing of currently manufactured semiconductors, even from OnSemi and other mainstream manufacturers, is log-jammed. This is a result of the perfect storm of Covid causing lines to be mothballed and then restarted and qualified, supply of the raft of chemicals needed, and similar problems Covid issues in the global distribution chain. Even vanilla parts are now out at end 21 early 22 delivery. And if you are going to build a PC - forget it. Processor chips have dried up as bulk users have stocked up (PC and automotive manufacturers mainly, but also smart phones and TVs). If you can buy one expect five times or more the nominal price. And pre-covid, particularly ceramic surface mount parts were on insane lead times, now even more insane. It will get better. From the end of this year onward supply ought to improve.