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Dipping your feet in the (mobile) Audiophile world for less than $200

April 7, 2011

You can’t deny that most people these days listen to music on mobile devices such as iPods, iPhones and other mobile phones and media players. When I was a kid (which wasn’t that long ago), when a new album came out, you had to go to a store and buy it either on vinyl or cassette (yes, CDs too) then go home to play it on your “Stereo”.  Maybe you had a portable cassette player too, but it wasn’t the only thing you played your music on. Today, people download albums the minute they are released right on their phones and in a few minutes, you are able to listen to media files without having to divert from whatever it is you’re doing. I know a few people that only use mobile phones, iPods or laptops as their main audio systems; having a dedicated playback system for Stereo Audio isn’t typical anymore (leisure systems these days are typically HDTVs and improperly-configured 5.1 surround receivers and “enhanced” speaker systems).

Distortion seems to be an accepted part of the listening experience these days. I don’t mean distortion in the audio processing sense – I mean distortion caused by compression of source files (CD tracks have a weight of 1,411 kilobits per second versus the highest quality MP3s that are 320 kilobits/s). Then you have cheap electronics that sacrifice size and weight of components for portability which further degrade the quality of sound, down to cheap drivers (speakers, earbuds) even cheap wire used to build and transmit the signal to the listener.

Like most things in life, once you get a taste of “the good stuff” you don’t go back. Your experience becomes more refined and thus your requirement for that experience starts to demand a higher quality. Sound has taken a huge back seat for the sake of portability, so we have to focus on the fact that people are not going to stop to listen to music the way they currently are; what we can do is make it possible for people to have a better listening experience without having to change the way they do it.

There has always been a huge monetary gap between what many consider consumer-grade and audiophile-grade playback systems. If you speak to someone who has spent a small fortune on an audiophile-grade system, it’s easy to feel like you can’t have a truly enjoyable listening set up for less than a few thousand dollars while someone who has spent a couple hundred bucks on an iPod might not even be concerned that their cool-looking white Apple earbuds don’t sound nearly as good as other headphones, much less think that they can use their iPod as the center of an Audiophile “starter” system.

This article will introduce those of you who may only own an iPod (or similar media player) & stock earbuds to the Audiophile world, for less than 200 bucks. This article assumes you already own an iPod or other media player. I truly believe that anyone who starts on a system like this will begin appreciating the quality of audio more, and hopefully, upgrade to an even more enjoyable (stationary) system down the line.

 

My DIY LOD Cable (Neutrik 3.5mm plug, Qables LOD connector, Canare Mini StarQuad. It also has a 68kOhm resistor to avoid getting “unsupported device” messages)

 

iPod/iPhone LOD Cable (about $15 or less if you make your own)

One of the cool things about the iPod/iPhone is the ability to bypass the built-in audio amplifier using the LOD (Line Out Dock). This allows you to get the audio signal directly from the DAC without going through the “not so awesome” amplifier stage that’s built in, which doesn’t supply enough power for higher impedance headphones anyway (more on this in a bit). Since we’re going to use a better amplifier (cleaner, more power) it makes sense to amplify the direct signal (and not amplify an already amplified signal).

If you have a different kind of media player, the best solution is to make or purchase a high-quality 3.5mm to 3.5mm cable that will not degrade the signal as bad as cheap cables do. Avoid distorting the signal before hitting the external amp by not fully maximizing the internal volume (amp).  Each device is different, so running it at 50-60% of the player’s internal amplification is enough juice for the external amp we will be using. Even if you have a LOD cable for your iPod/iPhone, it would still be a good idea to get a good 3.5mm to 3.5mm to connect the amp to other sources, like your laptop or portable CD player, etc.

CMoy headphone amp ($50 – $100+)

Dedicated headphone amplifiers have been around for some time. Many Audiophiles also have high-end headphone listening systems in addition to their loudspeaker systems, usually tube-based amps to drive high impedance headphones which typically cost a bit more than the headphones themselves. Many of the better quality headphones out there have a high oHm (impedance) rating, which means they require more voltage (power) to be driven at their nominal levels. Still, this kind of set up is not ideal for mobile listeners since you can’t put one of these tube amps in your pocket to take around with you.

In 1998, Chu Moy revolutionized the quality of portable listening by publishing a paper on making a high-quality, portable solid state amplifier that people soon started calling the “CMoy” (original article here).  The design is simple and uses high quality solid state components. With this amp, you can drive high impedance headphones like the Sennheiser HD 650 (or any headphones requiring up to 300 oHms).  It is also very efficient in terms of power, using a single 9v battery that often lasts months. You can make your own for about $30 and it is an ideal first DIY project if you’re thinking about making your own audio gear in the future. For the sake of this article, I will suggest that you look around and purchase one already made. They typically go for $50 or more, depending on who makes it and what components are used. A company named JDS Labs has added a “bass boost” circuit to the CMoy they sell.

My CMoy was made by CSG (Crystal Sound Group), an electronics company out of the UK. I like the CMoy design for its simplicity and “clean” electronics, so I didn’t care about any bass enhancements (JDS Labs’ website states “bass is increased up to 9.4 dB, just shy of a perceived 2x increase in bass volume”, that’s too vague for me; I want to know what specific low end frequencies are boosted and at what kind of slope – thanks, but I’ll pass).  CSG has an eBay store and what I dig is that they also allow you to customize things like the color of the face plate and LED. This particular CMoy costs about $75 including shipping, but if you do a search on eBay for “CMoy amp” you will find many DIYers selling their amps (check feedback ratings and you should be alright). These are the specs for the CSG CMoy:

Amplifier:

Burr-Brown Texas Instruments OPA2134 dual op-amp (one of the best FET input op-amps for audio, suitable for battery use).

ALPS volume control with power switch.

Panasonic 0.22 mf high quality polypropylene input cap. This cap is one of the best choices for the audio signal path. It provides clear, detailed high frequencies and solid bass.

Metal film 1% hand matched resistors. All resistors are highest quality metal film 1% tolerance and hand matched, to ensure both channels are identically balanced.

Gold plated jacks.

Power supply:

TLE2426 Rail splitter. This rail splitter provides long battery life and stable amplifier performance, which provides precisely balanced positive and negative supply voltages.

Panasonic ultra low ESR 470uF. This power cap has a fast discharge rate. This results in clear, detailed highs and low, deep bass.

Panasonic high quality polypropylene capacitors for noise reduction.

Many Audiophiles agree that in terms of design, portable solid state headphone amps don’t get much better than a well-built CMoy at any price point.

Grado SR80 ($99)

Highly regarded and considered to be possibly the best introduction to the world of high-end headphones, the SR80 is definitely a great value. Grado Labs, in my opinion, is a perfect example that high-quality sound does not have to break the bank. If you are considering a cooler-looking, more trendy pair of cans that cost 3X as much, at least know this: Grado Labs has been making headphones since the 50’s (one of the U.S.’ oldest hi-fi companies), the founder of the company, Joseph Grado was inducted in the Audio Hall of Fame in 1982 for his contributions in phono cartridge design and all headphones are built and hand-assembled in Brooklyn, New York – all by a company that staffs 17 people.

These are an open-design, so they won’t isolate sound. In turn, people sitting in your proximity will be able to hear the sound coming out of the drivers quite a bit. The tradeoff for isolation in open designs is that they sound more natural than closed-design headphones that are designed to isolate sound by enclosing your ears. The issue with closed-designed headphones is that they give you more of a boxed in, “in your head” sound than open-design headphones.

These cans are great for all types of music. They definitely have a character of their own without sounding “hyped” in a negative way; bass is “tight” and not “boomy” and I simply don’t think you can spend $99 on a better pair of headphones that are great for all types of music. They may seem a little awkward at first because they look and feel like something early telegraph operators might have worn, but you get used to them quickly (my biggest problem with them was the thin vinyl headband, so I bought a $15 aftermarket cushioned headband for added comfort). When you’re ready to step it up to the big leagues, they’ll be waiting for you with their flagship PS1000 model ($1,700).

Is it worth it?

If you don’t care about sound quality and feel that looks and portability are more important than audio quality (in other words, you’re a robot and music is only a backdrop for your daily activities) then chances are you probably won’t consider this a worthwhile upgrade.  Even though the amp is little in size, it can be a challenge trying to carry it in your pocket.  Also, the SR80’s cable is a lot larger in diameter than any of the earbud style headphone cables (four conductors), so that gets a little in the way as well.

As far as performance, this is where it all counts. You should notice a considerable upgrade in quality immediately. This is because you have added a better amp with cleaner electronics and a great set of headphones to use with your media player; you have also cleaned up the signal by using better wires to connect your devices. Headphone upgrade aside, you will also hear a difference when you plug in the SR80s directly to the player versus using them with the amp (the SR80’s nominal impedance is 32 oHms, so your media player will be able to drive them without needing the amp).

Bypassing the media player’s amp stage (iPod/iPhone) and using the CMoy instead will reveal a cleaner, bigger sound stage at any volume level, since the high-quality Alps volume knob does a great job of “tracking” the audio signal evenly on both channels. Try plugging in the headphones directly to the player to a comfortably loud level – you might notice how the lesser-quality internal amp starts to distort the signal as you increase the volume, then plug in the CMoy to hear how you can go very loud and still hear a clear, punchy signal.

Source files also play a big factor in upgrading your listening experience. Before getting my CMoy, I had only listened to MP3s directly from the iPod or through my Laptop’s (amplified) output. I can now say that what I thought was a generally bad quality associated to MP3s has a bit to do with the lesser quality amplifiers built into these media players. I guess what I’m saying is that when adding a better amp to the mix, MP3s don’t sound as bad as I thought they were. I now only listen to uncompressed (16/44.1) .wav files of vinyl transfers on my iPod Touch and I often look forward to listening to them on this system for enjoyment when I’m not home.

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