View Full Version : Hello from Dubai...
...where it hit 51.5C on Saturday :(
Another refugee from AT where I'm/was known as "Jack" to differentiate me from the other Nick. Long time member there. Been to Owston, had stalls at Audio Jumble, done stuff.
AT, IMHO, has spiraled into the abyss - sad really - I have closed my account. One day, may go back - I hope to (as I really like most of the other members), but not while the current toxic & petty environment continues.
I'm an engineer! Background as an EE (with physics & maths) - long time designer of SS kit, last few years have decided I rather like valves, so work with them too.
Most certainly not a purist - I pick whatever technology I feel best suits the aims of the current project in terms of solutions and sound. I design & build speakers, amps, line stages, whatever - I just like to design & build the whole signal chain myself. I also like to (try to) understand why something sounds the way it does and consequently will always question absolutist statements. I've carried this ethos into designing & building our own eco-house, and we'll shortly be building another.
Having said that, the main house's distributed audio is all Raspberry Pi 3s, Max2play, Vortexbox, IQaudIO DigiAMP+and only the uFonkens are from the workshops :) Oh, and rebuilt Quad 405-2s & ESL63s and other amps, speakers & stuff... lots & lots of... stuff.
Audio is a small part of what I do - mainly it's micro-power IoT environmental monitoring (mostly using TI MSP430s and similar), beekeeping, security & IT for serious financial organisations, and drive in the desert, hike in wadis, climb mountains when we can and travel. We travel a lot.
My far better half is a linguist who speaks many languages, including Arabic - she works with refugees in the UK & elsewhere - I work for a substantial (but below the radar) organisation that is the largest funder of anti-child slavery projects in the world and which is the third largest (after the USA and UK governments) funder of treatments for neglected tropical diseases - in the last 10 years we have treated over 280 million people. There are other massive projects too.
But I still like audio...
walpurgis
10-07-2017, 09:05
Hello Nick. Welcome to AOS.
Hmm, 51.5 Celsius? Definitely a bit too warm for me. I'd not cope with that! :)
Sounds like you have an interesting time. I do like your comment about questioning absolutist statements. Very little, if anything, is absolute.
Anyway, join in the fun and chat with members, this is a friendly place. And if you have any projects on the go, we'd like to see them.
Enjoy the forum,
Geoff.
welcome to the site Nick. Hope you enjoy it. 51 is close to the record temp... nasty at that level.
...And if you have any projects on the go, we'd like to see them...
Thanks for the welcome.
I'm not good at writing up projects, but I wrote up a couple of small ones on http://www.desmith.net/NMdS/Electronics - the Quad 405-2 rebuild is there and some other small stuff.
Most of the rest is in forum posts on AT or elsewhere - many other projects around the web - mostly HV stuff to do with solid-state Tesla coils & EM can-crushers etc.
Currently I'm working on an ultra-low-noise heater supply - there's a lot of tech in it and hopefully it'll sound good too - specs are 2-20V @ up to 10A, ideal bridge, SMPS pre-regulator, ultra-low-noise linear secondary regulator, current sourced (Hi-Z) floating output (can be biased +/- 1kV), programmable slow start and shutdown, opto-isolated power-good out and power on/off input.
Because of the use of the ideal bridge and pre-regulator, efficiency should be very high (c. 90%) and power dissipation very low - one of my pet hates with DHT and other purely linear supplies is the huge heat output, coupled with switching noise from the bridge and transformer ringing etc. (although that can be mitigated with suitable snubbing) - this is all well documented by Morgan Jones and others in Linear Audio and elsewhere. There are some cool features too, like true linear current increase during soft-start, not the usual simple RC model - much kinder on a cold filament...
Another advantage of an SMPS regulator is that I may make it a buck/boost, i.e. it could be possible to use a lower voltage xfrmr winding to drive a higher voltage heater... buck/boost is a more complex configuration requiring more real estate and adds to what is an already complex project - this is a nice to have, not must have.
There are a lot of engineering issues to work through, specifically with managing any EMI (not that big a deal), but I have a bunch of 6C33Cs and 13E1s etc. that need a good, compact, efficient heater supply... The prototypes are looking and sounding good but there is a bunch of work still to do.
As I'm mostly out of the UK and away from my workshops now, it's unlikely I'll have boards for others before the year end, but I'm always hopeful :)
...should have mentioned that I'm heavily into cold-cathode stuff, specifically making neon signs (I also do glass blowing) and lots of nixies...
I run the Google! neonixie-l group (https://groups.google.com/forum/#!forum/neonixie-l) (the main place for such things - been going for 17 years) which is very active.
Some of the stuff I've made:
GPS synched 6 x Z568 clock
20977
Neon "LetterBox" present for SWMBO with reclaimed oak and zebrano box (had fun getting those joints right)
20978
20979
20981
ITS1A Thyratron clock (rare tubes)
20980
I have a huge collection of nixies (over 100 types), and used to trade in them...
RobbieGong
27-07-2017, 17:23
51.5 !! :eek: heck ! Me wife n teenage daughter's will be over next week.
Knew it would be hot but that's nuts even for us sun lovers.
Any tips for the hols greatly appreciated - apart from the obvious stay out of the mid day heat, cover up and so on :)
It's cooled down a bit at the moment - days are mostly around the mid forties but it's nearly 10pm here ATM and still 39C.
Noone who lives here goes outside for any time during the day. It's really not good - the beaches etc. are just too hot.
Lots to do for visitors - what sort of ages are they and what do they like doing?
RobbieGong
27-07-2017, 18:53
It's cooled down a bit at the moment - days are mostly around the mid forties but it's nearly 10pm here ATM and still 39C.
Noone who lives here goes outside for any time during the day. It's really not good - the beaches etc. are just too hot.
Lots to do for visitors - what sort of ages are they and what do they like doing?
They're 14 and 18 like shopping. We all like nice food and drink that doesn't cost the earth.
I heard about the top of a mall or something where they do all sorts of food, pizza etc a lot cheaper than the hotel prices?
There's two HUGE malls - Mall of the Emirates and Dubai Mall - both are massive, both have food halls with loads of restaurants.
I'd go to Dubai Mall and have your evening meal at Wafi Gourmet, a great Lebanese restaurant overlooking the fountains and the Burj khalifa - eat there about 6:30 or later and sit outside if you can - the fountains are amazing as is the Burj khalifa, plus the food is authentic and reasonably priced. Nice place.
Ps. You can't drink alcohol in many restaurants and never outside.
Sent from my Nexus 5X using Tapatalk
RobbieGong
27-07-2017, 19:39
Nice one Nick, all noted :)
Should point out that Dubai is just not cheap - most things are expensive here, even the duty free... There are actually loads of malls but the two I mentioned are by far the biggest. We don't like them much as they are soooo big that it's exhausting trying to get stuff - it's daunting!
The food in the food halls is ok, but, hey, you can get fast food anywhere.
Most Arabic restaurants are Lebanese run, which is really good, though a few are actually Turkish (still good!). Waiters are helpful with choice and Wafi Gourmet is good.
The fountains and the Burj put on a spectacular show on the hour and at half past from 6 until 11 PM. 500ft high! Not to be missed!
https://thedubaimall.com/en/entertain-detail/the-dubai-fountain-1
RobbieGong
28-07-2017, 12:23
Should point out that Dubai is just not cheap - most things are expensive here, even the duty free... There are actually loads of malls but the two I mentioned are by far the biggest. We don't like them much as they are soooo big that it's exhausting trying to get stuff - it's daunting!
The food in the food halls is ok, but, hey, you can get fast food anywhere.
Most Arabic restaurants are Lebanese run, which is really good, though a few are actually Turkish (still good!). Waiters are helpful with choice and Wafi Gourmet is good.
The fountains and the Burj put on a spectacular show on the hour and at half past from 6 until 11 PM. 500ft high! Not to be missed!
https://thedubaimall.com/en/entertain-detail/the-dubai-fountain-1
Yes indeed Nick, This is what I've heard.
We have breakfast included in the stay so plan is to head out ion the evenings, shop, look around and eat cheaper hopefully at the restaurants like the one you've recommended.
I'm going to have to be very savvy with the dough I'm bringing as it wont be a lot.
Arkless Electronics
28-07-2017, 13:39
Thanks for the welcome.
I'm not good at writing up projects, but I wrote up a couple of small ones on http://www.desmith.net/NMdS/Electronics - the Quad 405-2 rebuild is there and some other small stuff.
Most of the rest is in forum posts on AT or elsewhere - many other projects around the web - mostly HV stuff to do with solid-state Tesla coils & EM can-crushers etc.
Currently I'm working on an ultra-low-noise heater supply - there's a lot of tech in it and hopefully it'll sound good too - specs are 2-20V @ up to 10A, ideal bridge, SMPS pre-regulator, ultra-low-noise linear secondary regulator, current sourced (Hi-Z) floating output (can be biased +/- 1kV), programmable slow start and shutdown, opto-isolated power-good out and power on/off input.
Because of the use of the ideal bridge and pre-regulator, efficiency should be very high (c. 90%) and power dissipation very low - one of my pet hates with DHT and other purely linear supplies is the huge heat output, coupled with switching noise from the bridge and transformer ringing etc. (although that can be mitigated with suitable snubbing) - this is all well documented by Morgan Jones and others in Linear Audio and elsewhere. There are some cool features too, like true linear current increase during soft-start, not the usual simple RC model - much kinder on a cold filament...
Another advantage of an SMPS regulator is that I may make it a buck/boost, i.e. it could be possible to use a lower voltage xfrmr winding to drive a higher voltage heater... buck/boost is a more complex configuration requiring more real estate and adds to what is an already complex project - this is a nice to have, not must have.
There are a lot of engineering issues to work through, specifically with managing any EMI (not that big a deal), but I have a bunch of 6C33Cs and 13E1s etc. that need a good, compact, efficient heater supply... The prototypes are looking and sounding good but there is a bunch of work still to do.
As I'm mostly out of the UK and away from my workshops now, it's unlikely I'll have boards for others before the year end, but I'm always hopeful :)
That's some ott no compromise filament supply! How about Cuk or Sepic for that SMPS? You may find a thread on linear V SMPS on here interesting... I've been arguing that so long as well designed and followed by suitable filtration and a linear regulator there is nothing to fear from SMPS...
I've got a fair few Nixies here at Arkless Towers... and 74141's to drive 'em... never done anything with them though.
Welcome. I thought it never went above 49.9 deg C in Dubai. ;) ;)
Welcome. I thought it never went above 49.9 deg C in Dubai. ;) ;)
Whatever Wikipedia and others may say, there were three of us who registered 51C or over... it was seriously hot hot hot. Hotter than Warrington, for sure :)
Last year, in Al Ain (about 150km inland from Dubai), it hit 62C at the government agricultural research station there - I know this as we have beehives there and the wax in the hives was melting and flowing out the front! (there is also an official weather station on the site).
dubai's record is 55c so well over 49.9..... plus the humidity adds plenty on to the feels like
RobbieGong
28-07-2017, 19:04
Basically common sense has to prevail - you cant giving it the big un staying out in it :eek: and we certainly wont be as much as we like the sun and hot weather.
From the numerous colleagues and people who we've spoken to, you stay out of it in the day and head out later in the evening when it isn't so extreme to check things out, eat and so, that's how we'll play it :)
...From the numerous colleagues and people who we've spoken to, you stay out of it in the day and head out later in the evening when it isn't so extreme to check things out, eat and so, that's how we'll play it :)
Absolutely - locals only go outside very briefly during the day in the summer - you're a puddle of sweat within 100mtrs or so. Everything is air-con though, even a lot of the car parks, so you don't get very yucky... The evenings are still mid 30s and humidity is high - at the moment (and for the last couple of weeks) we've had a lot of dust in the air, so visibility is down to just a few km - the dust is very fine & white & settles everywhere, which is why a lot people choose white cars. They look cleaner longer (you're not allowed to have dirty cars). We do a lot of off-roading too, which is an excellent way of trashing a car and having fun - plus, the mountains & wadis are extraordinarily beautiful and very few folk go there.
You wouldn't think it, but there's a rickets (vitamin D deficiency) issue here with some kids due to lack of sunlight - they have to take supplements.
http://www.msn.com/en-ae/news/newsenglishnews/dubai-man-cooks-egg-on-road-in-sweltering-heat/ar-AAoNViM?ocid=wispr
All sensible stuff aside, Dubai is a great hub - whilst the city is shallow, i.e. pretty much everything here is less than 20 years old and manufactured for effect, we are surrounded by amazing places - extraordinary countries and cultures. There are a HUGE number of fascinating countries within 3 hours drive or flight. My wife (who speaks Arabic) and I just love it.
One of the rare level (and good) bits of the track from Khasab in the north of Mussandam to Dibba in the south. 160km long, high up through the northern Al Hajar mountains - no other vehicles. The photo looks like we're not up high, be we are - this is an ancient river flood plain high in the mountains - been dry for many 1000s of years.
20986
That's some ott no compromise filament supply! How about Cuk or Sepic for that SMPS? You may find a thread on linear V SMPS on here interesting... I've been arguing that so long as well designed and followed by suitable filtration and a linear regulator there is nothing to fear from SMPS...
I've got a fair few Nixies here at Arkless Towers... and 74141's to drive 'em... never done anything with them though.
Some of my SMPS designs have made in into commercial audio products, mostly in the guitar effects world.
However, for my own amps, I really don't like the sound they produce when used for B+ - I'm happy with them as pre-regulators for heaters, but not as HT (except in the cases noted).
On the nixie front - I still have about 12,000 in stock :) 74141s are OK, but very old school and real-estate-costly way of driving them - some of the real biggies, like the CD47s/GR114s require a lot of care.
Personally, I quite like the panaplex segmented tubes as they can display alphanumerics and thus can do cute things like "four letter word" (FLW) stuff
Little two-digit IN-18 clock showing 11:36 (hours then minutes) plus a neat little Rasberry Pi 3 running max2play with an E88CC headphone amp.
20987.
dubai's record is 55c so well over 49.9..... plus the humidity adds plenty on to the feels like
It was a joke regarding building sites in Dubai... you're not supposed to work outdoors when the temperature reaches 50 deg C. It's no laughing matter really because it's resulted in deaths through the years. I have a family friend who lives out there.
Powered by vBulletin® Version 4.2.3 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.