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This is the excellent USB power pack I use when I travel.

2 x 2.1amp outputs. 8400mAh capacity.

Two digit Led display shows battery level

 

What SD CARD should I buy?

If you want an SD Card for your camera - these are the ones I use and recommend. 

I'd strongly recommend not to buy any SD cards off ebay - I've heard about too many issues with counterfeit cards - often sold on by unwitting resellers. My inbox regularly gets messages from people who bought a £150 camera then cheaped out and bought a £3 memory card on ebay - Then when it doesn't worth they blame the camera! It doesn't make any sense. Good memory is cheaper than it's ever been - see the links above.

A lot of HD cameras will not work properly with cards larger than 32GB (cards over 32GB are usually SDXC rather than the SDHC standard used by 32GB cards. SDXC cards use the ex-FAT system rather than FAT32 - in short they are a different standard). - so don't just buy the biggest card you can afford - read the specs in the manual to see what it accepts.

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CLASS 10 UHS-1 CARDS (For HD Cameras)

 

U3 CARD (For 4K cameras)

 

 

SPECIAL DASHCAM CARDS

The SD card in a dashcam is re-written over, more frequently than in other types of cameras. Some manufacturers void their guarantee if an SD card was used in a dashcam. So, no surprise, there are special High Endurance SD cards made just for dashcams...here's some.

 

VERY IMPORTANT. These links take you to the product, however Amazon have three different ways of selling. There's Amazon Direct - This means that you are only dealing with Amazon themselves, then there's other sellers that use Amazon's facilities - these show as Fulfilled By Amazon and finally there's Market Place sellers that advertise on Amazon, but operate independently.  I strongly recommend that you only use the first...the Amazon Direct - Sold By Amazon option. Even if it appears that you are paying a couple of £/$ more it is more than likely you are comparing the price of a real item against the price of a fake.

To give you an idea of the extent of the fake goods problem. In a 2016 survey by Apple - 90% of the 'Apple' chargers sold through Amazon - using the other the two methods..which includes the "Fulfilled by Amazon" option -  were found to be counterfeit....90%! 

            

 
« Bring out the Gimbal | Main | Dashcam Battery pack lets you record whilst parked »
Sunday
Jun052016

Retro HiFi: The DBX Disc

One thing that often comes as a surprise to anyone getting into vinyl for the first time is surface noise. As soon as the stylus touches down on a spinning disc there’s a noticeable background rumble. You could spend thousands in trying to eradicate this, but turn the volume up and you’ll discover that whenever one object scrapes along another, surface noise is inevitable. 
  
The absence of any background noise was one of the things I noticed when I listened to a CD for the first time in 1982. The complete lack of vinyl rumble, or tape hiss between tracks was something that was impossible to miss. A father of a friend who sold BAE aircraft around the world brought a Sony CDP-101 player back from a business trip to Japan. I remember turning the volume way up in order to hear what wasn’t there, just as much as what was.
  
In addition to no surface noise the new CDs had no static cracks and pops, and classical music recordings benefitted from the expanded dynamic range offered by the new format. Other attractions were of course the smaller size, longer playing time, easy track access, and a resilience to dust.
  
It turns out that many of the ‘new’ features available on CDs were already possible with Vinyl, it’s just that most people weren’t aware. Track access, random play and  each side play were all possible with the right turntable. Lesser known is the fact that zero disc noise, CD levels of dynamic range and reduced pops and crackles from dust were all features available on the obscure DBX disc format since the early 1970s.
  
In this video I look at (and listen to) DBX discs for the first time, and I’m shocked with the results. Watch the video below to find out more. 
You can still find old DBX Disc decoders on ebay where you can also find some DBX encoded records. The Discogs marketplace is also a good place to source DBX discs.
  
UPDATE: 
In a (soon to be proved misguided) attempt to placate the angry crowds brandishing pitchforks and flaming torches - HERE IS A DIGITAL RECORDING of the first two minutes of Pramlatta's Hips. 
 
You can hear the needle drop at 2 secs in...the silence after that is the lead in and then the music starts. There has been no manipulation of the recording - it's just phono out from the DBX 224 decoder into the audio in of a Sony HDR-MV1 recording in PCM WAV
  
I still feel that analog audio can only really be experienced in person, not via a digital recording - just like a photo of a oil painting, while all the information is there it's just not the same ...but hey what do I know, I'm just some guy on the internet.

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Reader Comments (38)

Aaaah - the golden age of companders! Just before PCM and CDs became feasible and affordable, analog made it's last struggle. Under ideal conditions, companders could improve the audio quality dramatically. Alas - vinyl discs and cassette tapes/decks were far from perfection; most consumers were not even willing or able to clean the stylus or recording head regularly, let alone fuss with anti-skating or level calibration controls.

And in reality, things weren't as good as the numbers promised. While the professional noise reductions - Dolby A, Telcom and later Dolby SR - worked with little or none audible side effects, consumers had the choice between a mildly effective Dolby B with almost no trade-offs (if the recording cassette deck was properly calibrated) or rather effective systems like Adres, dbx, Highcom/Highcom II, SuperD, and then later Dolby C, that could produce audible artifacts. As a "bonus", their recordings sounded terrible when played without the matching decoder. The cassette tape and mechanism can produce dropouts and high-frequency loss - most companders amplify these shortcomings. Dito vinyl: Companders may reduce noise and crackles - but they cannot improve frequency response or compensate for the fact that the relative speed of vinyl drops towards the center of the disc. And of course, the different noise reductions weren't interoperable.

In 1989, Dolby Labs. came up with Dolby S. It delivered what engineers and consumers alike had always wanted: A noise reduction that is only mildy susceptible to shortcomings of the recording or transmission medium and whose recordings sound decent when played back without the proper decoder. Had it been introduced 10 or 15 years earlier (and at an affordable price), this system could have worked as the all-purpose noise reduction for all analog formats of that day. But in 1989, CD and DAT were at hand, CD recorders emerged into the professional market, MiniDisc and Philips' hapless DCC came around the corner and MP3 was on the way. And long before video went digital, TV audio switched to Nicam on terrestrial broadcasts and via satellite with the infamous D(2)-MAC system.

Just for the - haha! - record: CBS introduced the CX noise reduction for vinyl in 1981. (https://en.wikipedia.org/wiki/CX_%28audio%29) Interestingly, the acronym stands for "compatible eXpansion" because CBS claimed, CX-encoded discs could be played without CX expander in acceptable quality. That, however, was not the case - even unexperienced listeners noted audible noise trails etc. CX survived on the analog tracks of Laserdisc, which remained on NTSC discs for compatibility with the few old players that weren't equipped with PCM audio. (On PAL Laserdiscs, the analog audio tracks had to be dropped with the introduction of PCM.)

May 6, 2017 | Unregistered CommenterKurt Mueller

I've been assembling a video on the subject of CX for a couple of months. It should be out in a few weeks.

May 6, 2017 | Registered CommenterTechmoan

Interesting... I'll be back!

May 6, 2017 | Unregistered CommenterKurt Mueller

Watched this video on YouTube, thought -- that's good, -- ordered a 224 off eBay, some discs from Discogs, and voila! a functioning dbx setup, can't do the tape loop with my modern receiver, but i have a USB deck with RCA out (as well as my Thorens for normal vinyl) that seems to work perfectly, sounds excellent to me.
Keep up the interesting and informative vids.

May 25, 2017 | Unregistered CommenterMike Rowland

I'm glad you managed to give it a go.

May 25, 2017 | Registered CommenterTechmoan

I recently found an old tape deck with DBX and I was wondering if DBX, from my tape deck, could be used to decode a DBX record. I have a feeling that the encode/decode is different from each other but I have been unable to find any information on the difference between DBX tape vs DBX disc.

June 23, 2017 | Unregistered CommenterBillie

From what I understand they are different. The decoders have a separate button for each variant.

June 23, 2017 | Registered CommenterTechmoan

Hi, great video, but how about dbx and reel to reel recordings, did you try it?

January 27, 2018 | Unregistered CommenterAnthony

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