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CMoy Amplifier

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At the Chicago/Great Lakes Meetup, Tipo33 and I started talking about high end audio equipment. I had brought my Grado SR80s and Tipo33 had his SR60s. Someone else also brought some form of Sennheisers but they were closed back, sounded mediocore, and were humungous when I put them on my head. Not my favorite.
Anyways, Tipo and I then started to talk about amps and other related Hi-Fi equipment and then found out he forgot to bring his CMoy. So like the great guy he is, he sent me the amp to try out. And as promised Ski, hereís your review.

Top of the CMoy amp, closed

Bottom of the CMoy amp, closed

A CMoy Amp was designed by Chu Moy, a member of the Headwize Community. It was supposed to be test for his Opamp headphone amplifier but turned out to be a great DIY amp. It is low cost compared to many other amps on the market and made a huge difference in sound quality. According to Warren Young, a CMoy and DIY amp enthusiast, you can source the parts for the amp for around $20. You can also get different Opamps and customize the board more. Iíve seen a lot of discussion on Head-Fi about that. Itís also portable because of its size and you can mod it to have different LEDs, have a rechargeable battery, plug into the wall, and customize the Opamp.

CMoy opened up, that proto-board is so cute!


* Setup
* Playlist
* Aesthetics
* Battery
* Sound Quality
* Final Thoughts

At home, I have an Omega Striker 7.1 soundcard in my rig, Grado SR80s, and the CMoy. And just to test it out even further, I brought the CMoy to work where I use Skullcandy Titan earbuds and the work computer. The bass boost was kept on for most of the time; I tried it for ten minutes without the bass boost and the sound sounded lacking so I flipped it back on. And because I didnít have the wall plugin, the CMoy was powered by 9V batteries.

I then tried it in the following configurations:

* With no sound card and no amp
* Just the CMoy amp
* Just the soundcard
* Both the CMoy amp and the soundcard
* Listening to the setup with SkullCandys

I typically only listen to metal and hardcore but I wanted to spread the music selection across a wider range to fully appreciate the amp. Even though I listed songs from YouTube, I used Spotify or SoundCloud to listen to the music. I also listened to To the Windís Empty Eyes CD (I got a pre-release copy when I saw them with the Greenery on 4/29/13.) Anyways hereís some of the songs I picked out. And shoutouts to Dubsgalore who introduced me to Archie V; now I canít stop dancing.

Archie V - Rosa
Archie V Ė Alive Remix
Backtrack Ė Too Close
Cancer Bats Ė Hail Destroyer
Dipset Ė More Than Music
Wu Tang Clan Ė Gravel Pit

This thing is in an Altoids box!! Itís so ****ing cool. I canít even handle it. Since it is a tin box the enclosure is pretty solid. The only thing I donít like is that the latch seems to be wearing or could wear after much usage and easily flip open. A bit of tape might solve this but Iím sure thatís just a minor detail.

The cutouts in the case are solid. I can turn the volume dial with one hand without supporting it with my other hand. And the jacks for the wires are way stronger than I thought. They also anchor the little proto-board in so that it doesnít move around too much. Tipo also has tape on the bottom side, I believe, which helps to anchor it in. If I flip it upside down with the top open, nothing falls out.

Battery Life
According to this link at Head-Fi, one non-rechargeable 9V battery should last around fifty-five hours. Iíd say this is pretty accurate. The battery that was in the amp originally lasted for about four hours, but it burned out since I accidently left it on overnight while I slept. I also think that the cold weather drained some of the life from the battery as well as Tipo33ís previous usages. The next battery lasted from 4/20/13 until 4/30/13. Iíd say I listen to music about five hours a day, between work and home, so the numbers work out.

Edit: The FAQ on JDS Labs' site confirms the battery time and shows a formula that will calculate the battery life.

When I listen with the CMoy I try to always turn it off if someone comes to my desk or if Iím not listening to it. Disposable 9V batteries are a bit pricey and Iíd like to try and prolong them as much as I can. It cost me $7 at Radio Shack to buy two of them. And I was in a rush to pick some up the battery died on 4/20 and I really wanted to get in on the 4Grabs buy.

Sound Quality
1) The Grados have a nice neutral sound with an open back so you can hear your surroundings. The bass is actually present and not just a ďlower noteĒ when I listen to music. That being said, itís not that deep but it does exist. Upper end sounds clear and almost reminds me of being at a concert since I can hear the music and other things around me.

2) With just the CMoy amp and my Gradoes, I instantly realized what people meant when they said that the 80s have really nice bass. You feel it when thereís low end. Listen to Rosa and try not to dance. Try it. It reduces me to this. The higher end is also very crisp and the open backs make the soundstage such that I can listen to music but hear everything around me. And it just makes the music more realistic for me. Like Iím actually at a venue/concert listening to something. The high end is clear and notes donít get lost when there are solos or intricate guitar parts going on. If I listen to music in my SkullCandy buds, the sounds almost get meshed and entwined together. Or certain notes get lost in the mix because I swear listening to my Grados made me rediscover my entire library again.

3) As I said above, the soundcard is an Omega Striker 7.1 that I bought for pretty cheap off Binge. After struggling for hours to get the driver to work, I discovered that it really boosts the higher end and makes it a lot cleaner and clearer. However, the bass is still lacking.

4) I know everyone in the CMoy discussion thread told me not to do this but I hooked up my soundcard to the front panel headphone jack and then into my CMoy and then into my Grados. I was told to keep it Ēline levelĒ but I didnít think the sound was too bad when I ran it from the front panel. In fact, I felt like this produced the best sound quality. The bass was deep and the upper end was clean. I think the first two days I had the amp/soundcard/Grado setup, I never took anything off. I just listened to music for what seemed like fourty-eight hours straight :D. I seriously donít think Iíve had such a good setup before and I can easily see myself falling into the rabbit hole/wallethack that is high end audio.

5) The SkullCandys? Well letís just say they play music and fit in my ears. Plus they were cheap. I wonít be bummed if I ever lose them or anything. When I listen to music with bass in it, it registers as a low note and not as a frequency that I feel. Disappointing honestly. But even these lackluster buds can be improved with the CMoy and that really surprised me. The bass was nice but the high-end was still muddled. Oh well.

Final Thoughts
I need one of these in my life as soon as possible. They make all of my listening experiences way better. Deep bass, clean high ends, and overall fuller richer sound make this a must have for me. If youíd like to order the parts yourself, you can source most of it from RadioShack as I said above. Otherwise, JDS Labs sells kits which has everything youíll need but the mint tin. If you want to see what other GHers have to say about the amp, check this link out

Oh and everyone go say something nice to Tipo33 since heís leaving us for Italy. Cheers brother, hope to continue seeing you on GeekHack!

Other Random Pictures:

LED and Wall Plugin Port

Volume Knob, Audio in and out ports, takes a 1/8Ē plug

Grado SR80iís

Very nice review :) A pretty awesome product that uses an altoid box? Convinced me

Thanks moonprismsis! And you can also use Penguin Mints tins which are really cute. ^__^

Thanks for the Shoutout Bro

I hope more people here discover EDM

Making this on my own would be really cool!

I'm glad you enjoyed the amp, and don't worry, I will be hanging around GH for quite some time to come.  Especially since you've volunteered yourself as my proxy :p


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