Dolby S – S is for surprise

After having watched Techmoan’s Cassette video I couldn’t resist and bought myself a cassette deck with Dolby S. In my case it was a Yamaha KX-580.

How I used to use cassettes

Before I bought a Minidisc recorder in 1996 or 1997 I used Metal cassettes, recorded them on my Telefunken twin deck and played them on the Alpine stereo in my car. The sound was usually fine, except the very annoying tape hiss you got all the time.

First impressions

My first impression with the Dolby S deck: Great! Much less hiss than I remember, despite only using a ‘Normal’ cassette. It was a Maxell UR 90 tape I had lying around, still shrink-wrapped. I think my wife got it when her previous university phased out tape recorders. Reasons for the better sound compared to what I remembered? I guess I either remember there being more hiss than there actually was, my ears got worse or my Telefunken deck or Alpine stereo had a problem – or maybe it’s a combination of all of these reasons.

Dolby S

I was however brought back down to earth when I tried did a comparison and tried out Dolby S.

I was expecting a lot – having watched Techmoan’s video my expectations were pretty high, but then there were also other documents, like this PDF, which doesn’t have an author, but seemed pretty well written and said things like:

“We have found that, at the highest playback levels likely to be encountered in the home, sophisticated listeners subjected to A/B comparisons of CDs and Dolby S-type cassettes are unable to identify which is which with any regularity.”

or

Dolby S-type Cassette Decks provide performance comparable to that of a Compact Disc, utilizing standard (Type I) blank cassette tapes.

There’s also this diagram in my cassette decks’ manual:

responce
from the Yamaha KX-580 manual

It also gives the impression that Dolby S will outperform Dolby C in terms of noise reduction.

Reality / the test

What I got was very different though. For my test I recorded two songs from YouTube’s audio library on a new Maxell UR 90 cassette: Far Away by MK2 and I’m Fly by Gunnar Olsen. Both were burned on a CD-R and played back on my SEG DVD player (also available as a Yamakawa, these were affordable multi region DVD players from the 1990s that actually use an ATA DVD drive). I recorded the same two songs without Dolby, with Dolby B, then Dolby C, then Dolby S. I then played them back using the same type of Dolby used for recording, i.e. the Dolby B recording was played back using Dolby B, etc. and recorded the output using 96 kHz and 24 bit.

To my surprise the noise floor of the Dolby S recording was higher than that of the Dolby B recording. If you adjust the input levels for these songs, maybe slightly conservative, then the noise floor level without noise reduction is -48 dB, with Dolby B it’s -57 dB, with Dolby C -59 dB and with Dolby S -54 dB.

The cassette deck seemed to be in great condition, so I wonder whether something is broken or whether this is normal behaviour. It would be great to hear from you if you have a Dolby S deck.

noisefloor
Noise floor comparison

I put the recordings on YouTube, if you want to listen for yourself, but I should add that even though I recorded them with 96 kHz and 24 bit I had to use AAC with 48kHz and 320 kbps for encoding the video. I don’t know whether YouTube will then reencode the sound again. I guess what quality is sent to your machine will depend on the quality of your internet connection, so what you hear is only to some extent representative.

Here are the videos

No noise reduction

Dolby B

Dolby C

Dolby S

 


Techmoan also mentioned cassettes in his blog.

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IKEA’s Vinninge battery charger

I mentioned the Ladda batteries yesterday. Another thing I bought in IKEA is their new Vinninge charger.

IMG_1675

Only £1.80 for a charger with two separate charging channels, that can charge AAs and AAAs. How could I resist?

It is USB powered, so you can’t except a high charging current. According to the manual it is 220 mA for AAs and 110 mA for AAAs and the charge is terminated by individual minus delta voltage sensors (-dV). There’s also a separate safety timer and detection of non-rechargeable and damaged batteries.

IMG_1676

The LED, placed behind the plastic case, so it is illuminating the case, is for both slots, so if you charge two batteries and one finishes early you wouldn’t know until the second one has finished.

IMG_1679

Their existing Ladda charger, reviewed by Henrik Jensen, has a bit more oomph: it charges AAs with 1000 mA and AAAs with 500 mA. There’s also a new charger with 12 separate charging channels, called Storhögen, charging AAs with 250 mA and AAAs with 110 mA.

I hope Henrik will review the Vinninge charger on his Lygte Info web site in the future.

IMG_1681
The LED is behind the plastic case and can be seen through the case

IKEA’s Ladda rechargeable batteries

I bought some new rechargeable batteries at the weekend: IKEA’s Ladda batteries.

IMG_1673

IKEA’s new rechargeable batteries look quite different to their previous ones, the silver / green Chinese made ones with 2000 mAh. The new ones look a bit like Eneloops as they have a a similar, slightly glittery label/wrapping around the battery’s body. They are also made in Japan, like the Eneloops, and the packaging implies that they are charged by solar energy, too – so  it wouldn’t come as a surprise if they were made in the same factory as Eneloops.

IMG_1674

Unlike Eneloops there is however no claim of low self discharge with the Ladda batteries – nevertheless, the 1,000 mAh Laddas seem similar to Eneloop lites and the 2,450 mAh Laddas seem similar to Eneloop pros.

Eneloop (left) and Ladda (right)

I bought their low capacity version, the 1,000 mAh Laddas, four AAs for £2.75 – thinking they might be similar to Eneloop’s ‘lite’ batteries, which have ‘up to’ 1,000 mAh. When I discharged the Laddas in my Technoline IC8800 charger with 250 mA and charged them with 500 mA they ended up with a capacity between 993 mAh and 1020 mAh.

Eneloop (left) and Ladda (right)

The top and the label/case (not sure what to call it) seems pretty similar, the date stamp, too, just the format is different.  The bottom of the batteries is however quite different. The Ladda’s have a much smoother surface, at least compared to the latest Eneloops – I don’t have Eneloop lites to compare it too.

Anyway, even if they are from the same factory that doesn’t mean they are as good or use the same ‘ingredients’ or production methods. In any case, they seem pretty good value for money. I”m looking forward to trying them out.

diff

Another command I want to write down, like dot_clean, so that I remember the details:
diff – Compare files line by line.
Usage: diff [OPTION]… FILES
FILES are `FILE1 FILE2′ or `DIR1 DIR2′ or `DIR FILE…’ or `FILE… DIR’.

diff -rq folder1 folder2

e.g. -r (rekursive) and -q (brief output)

diff -rq /Users/memm/Backup/Documents/ /Volumes/Documents/

Fake Eneloops?

Having recently bought two packs of Panasonic Eneloops from BeaconShop (Amazon Marketplace), the BK-3MCCE model, I was wondering whether they were fake, just because the blind date stamp on them looked quite different to the one on my other Eneloops and because they were quite cheap – £6.99 (Including a battery case, which looks different to the old battery cases).

I thought I compare them with Panasonic’s official numbers, which can be found on their Polish web site to find out whether they are fake or not.


Everything I checked was slightly off, but not enough to make me certain that they were fake.

The capacity should be at least 1900 mAh, I measured 1755 – 1776 mAh with my Technoline IC8800 charger.

The weight should be ~ 27 g, I measured between 25.8 – 25.9 g.

The dimensions should be 14.35 mm x 50.4 mm, I measured 14.15 mm x 50.23 mm.


I guess I’ll just keep an eye on them and hope they are the real thing.

 

 

Update: I bought another pack of the latest Eneloops from Maplin, hoping they have to be real if they are from the high street, and they seem very similar to the ones I bought online. When I checked their capacity (after discharging and charging in my IC8800 charger) they were slightly better than the ones bought online (1,788 – 1,808 mAh), but still not as good as they should be. Looks, weight (25.7 – 25.9 g) and date stamps of the Maplin and the online bought Eneloops were the same, so for now I believe that the ones bought online were real.

Installing OpenELEC (on a Raspberry Pi)

After a recent update broke my OpenELEC installation (or was it a problem with the SD card?) I thought I better write down all the steps to get it up and running again, in case I need to reinstall it again in the future.

These steps are specific to the way I use Openelec (NAS, passwords, …). Generic advice can be found at http://wiki.openelec.tv/index.php/Raspberry_Pi

Download disk image

Download disk image from http://openelec.tv/get-openelec

Write the disk image to the memory card

Write the disk image to the memory card, see http://wiki.openelec.tv/index.php/HOW-TO:Installing_OpenELEC/Writing_The_Disk_Image

Booting

Boot Raspberry Pi with SD card.

Resizing storage seems to have happened automatically.

SSH default user is root, default password is openelec.

Set up IP address in router.

Audio channels

Change to fit: System / System / Audio Output / Number of channels

Accessing password protected shared folders

Edit Userdata/sources.xml so that Openelec can access my password protected smb shared folders from the NAS, see http://kodi.wiki/view/Sources.xml

Examples:

<music>
 <default pathversion="1"></default>
 <source>
   <name>Music (Bullfinch)</name>
   <path>smb://raspi:password@192.168.0.12/music/Music/</path>
   <allowsharing>true</allowsharing>
 </source>
 <source>
   <name>Streams</name>
   <path>smb://raspi:password@192.168.0.12/music/Streams/</path>
   <allowsharing>true</allowsharing>
 </source>
 <source>
   <name>Music (local)</name>
   <path pathversion="1">/storage/music/</path>
   <allowsharing>true</allowsharing>
  </source>
 </music>

Add to the library

Music Files, choose source, long press, scan source to library.

Video Files, choose course, long press, choose what kind of content it is (movies, TV series).

 

 

Adding a hard disk to a ZFS pool

Adding a hard disk to my ZFS, based on this How To.

Disks|Management

Import disks

Click on tool next to hard disk for settings (standby time, description, …)

 

Disks|Format

Choose disk

File system: ZFS storage pool device

Format disk

 

Disks|ZFS|Pools|Virtual device

click + to add new drive (type is again stripe, like first one)

Apply

 

Disks|ZFS|Pools|Tools

Choose command ‘vdev add’, it should pick the right virtual device.

Send Command!