HiFi Hacks

I love iTunes as a music library manager. It’s great for organising music and podcasts, and it syncs with my iPhone, which I use everyday. Even though it’s getting on in years it’s still the best. The only problem with it is that I have iTunes installed on my laptop, and that means listening to music through the unbearable and tinny sounding laptop speakers. I do have a perfectly good stereo on the other side of the room, but using that with iTunes on my laptop means connecting it with a long audio cable to the ‘Aux In’ of the stereo, or getting one of these things:

This is that Airport – which has a clever feature of piping music over wifi to your stereo. It has a neat wall-wart design which means you can plug it in behind the TV/stereo and forget about it. There is not a lot else to it, it does it’s job well. As it happens, it’s the only thing that can do the job as Apple have protected this wireless communication with encryption, so you can only do this with a genuine Apple Airport.
This is aggravating, because like a lot of people, I have a media server PC running right next to that stereo, which has a sound card and could be connected to the Stereo easily with a $1 audio cable. But playing iTunes music through that PC is completely impossible. That is, until now.

You may remember reading in Slashdot about the clever guy who managed to extract that key. Well, because of him we have a bunch of new open source projects – including ‘shairport’. This is an Apple Airport emulator which will run on *nix systems, but there is also it’s Windows cousin ‘shareport4w’ – this is just what I wanted.

Installation is very easy – just name the shairport4w instance (I use the name of my server) and from that point on the fake airport is detected by Itunes and the Iphone too! Awesome.

There have been a few posts over the net recently on how to ‘upgrade’ the Sennheiser HD555 to make it sound like it’s more expensive brother, the HD595. Moreover the hack requires no parts, as it is in theory a removal of parts which were included in the HD555 to make it sound worse, on purpose. Apparently, the actual driver units used in both models are identical. Anyway, a ‘free upgrade’ is always very hard to argue against, so I decided to try for myself this mod with my trusty pair of HD555s.

My pair I have had for years, at the time I got them they were the cheapest good pair of headphones you could buy that had a relatively high impedance of 120Ohms. This was to support my pipe dream of using them with an OTL (output transformer-less) valve amplifier. I think maybe the impedance is lower these days.

The process is fairly simple, and is well illustrated in this video. First step was taking off the ear pads. Easily done, just yank em off. This does take a bit of force.

Then the dust covers need to pop off.

The part we have to remove is behind the driver, and to get there we need to unscrew them. There are 3 small screws each side. One side of mine only had 2 screws – one was missing, I could not find it on the floor or the table. At the time I thought was poor build quality!

Here you can see things starting to go wrong. The circular transducer has popped out of the plastic mount. This is bad news indeed because it leaves exposed and vulnerable the delicate mylar dome of the driver. If you touched this you would probably dent it, even if you were careful. So, I had to snap it back in, with a scary amount of force.

The target part is now clear, it’s that piece of rubber/foam tape on the plastic grill. The expensive HD595 models don’t have this piece, so removing this must make these sound just as good as the expensive ones, right? Anyway you can just pull these off with your fingers no problem.

Now for re-assembly. At this point, I made a discovery of the missing screw – it must have flew out and embedded itself in the other side’s dust cover! So Sennheiser’s build quality reputation is restored.

And the verdict? Well I have to say I can’t recommend it. It sounded… pretty much the same as before. Obviously this is not a scientific analysis, and the sound wasn’t bad, but I think if you have a pair I would say don’t waste your time or risk your ‘phones.
I can’t help but think maybe this bit of tape wasn’t a HD555 sound quality crippler, but perhaps something to stop an un-wanted resonance in the plastic grill, in which case I just made my headphones worse, not better. At any rate, if we were to really like the idea of subtracting unnecessary stuff, why don’t we just get rid of the plastic grill altogether, and the metal one behind that? Well, apparently people are doing this already.

After involuntarily donating my beloved Klipsch Image X1Headphones to a thief, I was initially attracted to these
because of the braided cable – which seemed like it would help alleviate the age old problem of earphone cable tangle-age, which drives me insane. Also the brand, Koss, is fairly respectable so they should be a good performer. They were purchased off Amazon, at just under the £30 mark. For that, you get the a small package that includes the giant rubber adaptors, 2 sets of alternative ‘memory foam’ ones, and a leather (look) pouch.

What follows is my impression – but before we get to the catalogue of disappointments, let’s start with the good aspects:

1) They have very good bass, if that’s your thing.

(End of list)

So now for a few bad points

The rubber parts that go in your ear canal are effective for blocking out exterior noise. They look like they are huge rubber Christmas trees that would stick out of your ears a bit. Well they do. I’m not sure why they are so huge. They do come bundled with some ‘memory foam’ alternatives, which are like the yellow earplugs you jam in your ears. They are not very effective however, the driver units are quite big and heavy, and need the big ‘ol Christmas trees to stay in your ear.

While they do seal your ear canal effectively which stops a lot of noise, I noticed that when you turn your head you hear a crinkling sound, like there is cellophane wrinkling inside the drivers. This happens in both ears so is probably not a manufacturing defect, it’s just what they do. At fist it was infuriating especially since I wear these at the gym, where you are moving all the time.

The cord does have that cool braiding – however that does not stop the entanglement problem one bit. It’s still so flexible and fine that it can knot itself no problem.

So anyway how is the sound? Uhhh… bad. The bass is large but not tight or balanced. The mids are muddied sound like they are coming down a long pipe… which I guess they are (did I mention how long those rubber things are?), and the highs are abrasive. Like any piece of hifi equipment though, you eventually get used to the sound and not hate it so much. In more expensive gear this is normally referred to as ‘breaking in’ and allows a reviewer to knock out a paragraph or so of fluff about how the sound improves.

All in all I have to say that with the Klipsch Image X1s still for sale, and at almost half the price, you’d be mad to get these. Unless of course you love large and sloppy bass, and have absolutely huge ears.

Krzysztof Marcinek over at his site has created a nice tube amplifier. The difference with this one is that it has a USB interface, inside it has a Texas Instrument DAC with an integrated USB controller. The amplifier is a single ended configuration, and produces 2W. It looks like he has done a very nice job with the case construction, and would make a very elegant amplifier for some near-field monitors on a PC. The rest of his site is worth a look too, he has pictures and details of his other projects which include a few other home theater amplifiers, external DACs, and even a HT preamp complete with EL display!

The iPhone is an incredible device – there are two main problems with it:
- I can’t get one where I live
- The hardware has tremendous potential, but it is locked up, eliminating the possibility of installing 3rd party (or your own) applications.

The iPhone can be ‘hacked’ to make it possible to install applications, but doing so voids warranty and could cause problems when Apple wants to update your phone. Still, some brave people have done it, leading to very interesting scenarios. An example is this the ability to stream music off the iPhone.

This is achieved buy installing sshfs, FUSE and Rhythmbox, all of which are open source and freely available. The way it works is that the iPhone filesystem is mounted on a host PC over SSH. Rhythmbox (a media player for Linux) can access the filesystem as if it was local, and play any track it wants. The SSH link is set up with cached keys so no passwords have to be entered manually.

This is great, and what hardware should be. With the addition of wifi, the possibilities for the iPhone are immense, this is but one of them.
Full walk through is at fsckin w/ linux.

Millet Max Millet Max The Millett Hybrid Maxed, is a vacuum tube and solid state hybrid headphone amplifier. It is the latest refinement in a series of headphone amplifiers that began with Pete Millett, its namesake. The schematic, BOM, and PCB layout are freely available, and many people have already created a copy.
The design uses low voltage tubes which were typically used in situations like car radios, where high voltage supplies were not available or convenient. The tubes are supplied with 24V DC from a ‘wall wart’ supply.
The design, as well as being a nice polished one with the kinks ironed out, includes nicities such as a delay mute circuit to stop the power switch thump in your headphones, and the option to include a BJT ‘Diamond Buffer’ or MOSFET output stage. It even includes PCB footprints for LEDs to illuminate your tubes!!
Colin Toole is currently taking names and quantities for a group buy of the custom PCB designed for the MAX amp. The expected cost is $12, however, it could be less if enough people place orders. Orders can be placed until June 3rd. More than 253 have been spoken for so far.

MAX Overview – Link & here’s where to get the PCB.

Recently I was given an XBOX because the owner upgraded to an XBOX 360. After the initial
thrill of Crash Bandicoot wore off, it ended up with the fate of most games consoles, sitting unused gathering dust under the TV. That is, until I heard about XBOX media center. This is a fantastic piece of software which you install on your XBOX, and turns it into a fully fledges media player, capable of presenting videos, pictures and mp3s right on your TV. Since the XBOX has an Ethernet port, you can play files stored on other computers over the network, or play video streamed off websites like You Tube. You can also play media stored on the hard drive. Since the project uses open source media players, there is no trouble with file formats, it will play anything – DivX, Mpeg, H264, MP3, AAC, OGG, basically anything that a Celeron 733Mhz CPU could play.
It’s not all smiles and sunshine though – there are two major problems. The first is that the legal status of the project is somewhat hazy, it is compiled using the developer’s toolkit supplied by Microsoft to official game developers, which is presumably licensed only for official XBOX development. For this reason acquiring XBMC is a little more difficult than just downloading from a website, you need to find it in the seedy underbelly of the torrent world. Second, even if you get the binary, it won’t work on your XBOX unless you ‘mod’ it. Microsoft designed the XBOX specifically to only play ‘signed’ software, that is software that has been approved by Microsoft. You need to modify your Xbox to get around this.

Modding

There are two types of modification, soft mods and hard mods – both achieve the same end result however. Soft mods use software exploits in known versions of some games to get the XBOX to execute unsigned code – usually a small program which will flash the bios with a new modified (i.e. non Microsoft) version. The other type is the mod-chip, which is a replacement bios chip that you solder into the Xbox itself.
Back in the old days when the XBOX first came out, mod chips were very common and most people used them to be able to play ‘backups’ of their games, i.e games that had been copied onto a DVD-R. For some people no doubt it was a way to play cheap pirated copies of the then expensive games. Nowadays, with the new XBOX released and original XBOX games going for peanuts in the game stores anyway, mod chips are mainly useful for unlocking the Xbox’s ability to play unsigned code like XBMC or Linux.

There are many sources of mod chips out there, from cheap and cheerful to very expensive. Some have the ability to ‘turn off’ and effectively turn your XBOX back to stock, which is handy if you connect to XBOX live. Some even have an LCD interface for putting a small display on the front of the box – which is a feature XBMC can support.
I chose the Duox2 chip, which was easy to install with just an IDC header to install (Thanks Microsoft that makes it real easy) and a couple of wires. Now I can boot XBMC by powering on the XBOX with the power button, and boot the original XBOX bios by powering up with the eject button; but I never do.

Installing the mod chip has also allowed me to replace the piddly 8gig internal hard drive with a bigger 20gig drive I had lying around, but I could have installed a 200gig+ drive, the new mod chip bios supports it.

Installing XBMC

For me the installation of XBMC was the hardest part of the process. Generally the first thing people do after modding an XBOX is install a new dashboard, which is a replacement for the stock MS ‘green menu’ – in other words the default application that the bios kicks off after booting. The replacement versions have niceties such as FTP servers which allow you to install new software onto the XBOX over the network. To install this, you need to burn an installer image onto a disk that the XBOX can read – which takes some trial and error. It can read DVD-R, and some CDR media. It took me 3 different brand of CDR before I found one that my XBOX can read, and even then it was 50/50. Apparently every XBOX is different in this regard and all are very picky! however once the disk booted, the XBOX started the FTP server and I was away.
I copied the XBMC binary to the hard drive and used the ‘shortcut’ method to make it the default application, i.e the program that is started at boot up. Once this was done, restart and in seconds XBMC is up and running! XBMC itself also has it’s own FTP server so while it is running you can install other applications/media onto the hard drive.

What XBMC can do

Once XBMC is installed, then the fun starts.
First, I pointed it to my shared NAS (200Gig on an NSLU2) drive with all my mp3s. With a click of a button they were all indexed and can now be searched by genre etc. Now I can search for an album and have it play while viewing the album art, or a visualization etc. When I get time I can create playlists, or copy over my itunes m3u playlists. Smart playlists are also supported, although at the moment you have to get your hands dirty with the XML config files to make them.
Next, I pointed XBMC to all my home movies, again on the shared drive, this time in a different directory. All these were previously unplayed because they are taken with an MP4 (H264) Sony Digital handicam and they playback terribly on my computer. Now I can watch them fine full screen on the TV – you can’t beat that. XBMC also has a nifty feature where it ‘stacks’ movies: I often have half a dozen movie files in the same directory, each with a filename with a number in it that the camera automatically increments when I take the movie. Example, mov1456.mp4, mov1457.mp4 etc. Stacking makes them look like one file in the user interface, and all the movies are played one after the other. Fantastic!
After that I do the same for my photos, and the divx/xvid movies and podcasts I happen to have.
Finally I install the youtube script, and search for and play stupid movies off youtube on the TV!

The great thing about it though is the ability to customise. Not only is it extremely flexible about what you can play and where you want to store it, but also the whole application can be ‘skinned’ to look completely different. Apparently someone has skinned it to look and behave like Apple TV, but.. better.
Also XBMC has a python interpreter and a couple of built in python modules that let you script the entire interface, from opening dialogues and showing buttons to playing video. There are al ready several scripts out there from the youtube one above to ones that catch podcasts and play other online streaming media. There are even scripts that play tetris – but if you do feel the need to play games remember the XBOX still works as a games console, or alternatively you could acquire MAMEOX and some arcade game roms and play old arcade classics like Street fighter, Double Dragon, and Gauntlet on your TV with your XBOX controller!

Just a quick note to anyone contemplating using the NSLU2 as a jukebox, the NSLU2 has just had a new release of the Debian Installer. Release RC2 includes a new totally open source ethernet drivers, as well as nice things such as LED drivers, and more support “out of the box”, not to mention the newer 2.6.18 kernel.
I updated my slug from DebianSlug to proper Debian – and it was pretty easy. Alsa sound works well. Now kernel updates are a lot easier, with proper debian support, the slug can flas itself!

When is comes to speakers, more mass means better sound. Usually you can guage how good a speaker will sound simply by picking it up. Light & plastic = Bad Sound, heavy and ‘dead’ = Good Sound. So with that in mind, if you are going to build your own speakers, why not make them heavy as you can. Well Markus Egger had that exact throught, so when he built some speakers he used concrete. Not just stock concrete tube, but cast in custom designed and build molds using lost wax method! What makes this project even more remarkable is that these are not two large stereo speakers, but a set of sattelites for surround sound.
The site is in German but there are lots of pictures of the process or you can use the fish.

Link

At the top end of the hi fi industry, the ‘money no object’ loudspeakers exist. These creations go to great lengths to achieve the highest sound quality. Some use niche or even impractical technology, not found in the standard ‘wooden box’ loudspeakers us mere mortals can afford. Some are huge and lack greatly in ‘WAF’ (Wife Approval Factor), but at this end of the market – who cares!
Here are some of the weirder looking speakers available out there:
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