$60 Pack of Awesome: JDSLabs Cmoy

jdslabs_cmoy_01

After finishing the portable amplifier shootout, a few people asked me if I could do a review on more affordable portable amps — additionally to see how the cheaper ones compare to the flagship $300 and upward-class amps. I’ve listened to a lot of entry level portable amps, and in my opinion the Cmoy design is still one of the best sounding sub $100 portable amp there is. I’ve listened to so many different Cmoys builds, from point-to-point, protoboards, dual layer PCBs, active ground cmoys, to dual mono builds running off of a Sigma11 power supply. Despite the large variance from one build to another, the Cmoys have maintained a good standard of musicality, and I’ve yet to find a Cmoy that sounds bad or unmusical.

The main problem about recommending a Cmoy is that it’s a DIY project, while most people look into buying a finished product. Then I found out about the JDSLabs Cmoys, and the fact that they sell either fully built Cmoys or bare PCBs really interests me. John explained that his Cmoys can be built as a standard build, or he can customize it to fit every individual’s needs better. The degree of customization is quite large, as he quoted some number of 200 possible different configurations. I thought, great! Send me one standard built, and send me another one with some customization on it.

THE PRODUCT
When the Cmoys arrived, I quickly unpacked the mailer box to see two Cmoys neatly sealed in a neat anti-static bag, complete with the customization notes printed on them. One amp was labeled as the stock build, while the other is labeled as a Low-Z (low impedance) set. The Low-Z amplifier comes with a lower gain than the stock set (Gain 3 vs Gain 6), and also comes with two TLE2426CLPs that gives the Low-Z amp double the current capacity of the stock builds. The Low-Ω set therefore is useful not only for IEMs, but also for low impedance headphones such as the 32Ω Grados, while the stock set is better for the other 50Ω and up headphones with relatively lighter current demands.

This is the stock build. Everything is properly labeled on the PCB including the input and output switch. Power ON/OFF is integrated into the volume knob.

 

This is the low-Z build with two TLE virtual ground current sources. (The two black transistor likes left to the Bass-boost switch).

 

Although JDSLabs doesn’t guarantee perfect Altoids case on each of their amps, the two I’ve received are flawless and free from dents and chips in the paint. The holes for the in/out jacks, volume pot, LED, and power adaptor jacks are very precise with zero slack. The potentiometer knob is of high quality anodized aluminum knob with rubber trims and clear dot marking. As you open the case, you find the PCB taking up less than half the space of the Altoids case, components placed laid out very clearly on a high quality dual layer PCB with a separate ground plane. The supplied manual is printed on a piece of paper, but it’s probably one of the best product manual I’ve seen in terms of product information for the customers. JDSLabs also supplied print outs of the frequency response curves of the two different amps, along with the configuration notes.

There are no labeling on the exterior of the case, but if you open up the case, you’ll see that clear labeling printed on the PCB of what each jack does. Inside you will also find a toggle switch labeled “BASS”, which boost up the bass section by 9.4dB, or “just shy of a perceived 2x increase in bass volume”, as JDSLabs wrote. Next to the Bass boost switch is the op-amp mounted on a DIP format switch. Everything about the build indeed is high quality. The LED brightness is just right, the input/output 3.5mm jacks grips very well and likewise the the DC input jack. The power switch is integrated into the volume control, but another nice touch John added is the positioning of another switch in the headphone out jack. When there is no headphones plugged in to the output, the amplifier will turn itself off, regardless of the on/off in the volume knob. All these bits add up to an impression that John is not just trying to make a quick buck selling pre-assembled CMoys. He truly sets out to create one of the finest Cmoy builds out there.

GENERAL SOUND IMPRESSIONS
Like most Cmoys I have listened to, the JDSLabs Cmoy take on roughly the same kind of tonality. Overall the tone is medium warm, semi relaxed and smooth, emphasis around the lower mids to midbass with a relaxed treble. Especially worth mentioning is that the JDSLabs is extremely smooth, and above average when compared to the other Cmoy builds I know. I listened to the JDSLabs with the Audio Technica M-50 and the Sennheiser HD650, and the JDSLabs were able to make good music out of both headphones. After spending a few hours with it, I noticed that this Cmoy is totally smooth from top to bottom with no discernible flaws, spikes, uneven transitions, or distortions, anywhere in the frequency range. I got even more curious and so I plugged in the Sennheiser HD800 to it, and like what I noticed earlier, I could not detect anything unnatural or unpleasant throughout the frequency range. The JDSLabs Cmoy was just smooth from top to bottom — and that is very impressive considering the HD800 often still find faults on much more expensive desktop amps. To have such as smooth tonal balance from top to bottom is truly phenomenal, as this little Altoids-cased amp costs merely $60!

Perhaps if I were to nit-pick, I would complain about the relatively weak low-bass performance of the amp. But personally that’s just asking for too much from a Cmoy design, as many other more expensive portable amps still have a relatively weak low-bass. The semi-relaxed pace, and the midrange emphasis makes it a good all-rounder amp with a wide genre bandwith. However, heavy fast-paced music fans would probably want a faster-paced amp than the JDSLabs Cmoy.

It’s a very clean build in and out.

 

POWER SUPPLY AND ROLLING OP-AMPS
The JDSLabs come with a stock op-amp OPA2227 from Burr-Brown. The stock op-amp is very good and natural sounding. It’s what’s responsible for some of that smooth sound I described in the previous paragraphs. However, I have other potent op-amps that I would like to try on the JDSLabs Cmoy. At first I tried replacing the stock op-amp with the famous OPA627. The 9V battery that comes with the amplifier barely meets the minimum specified operating voltage of the OPA627, and so I found distortions on semi-loud passages. A better idea is to use an external DC power adaptor, which not only eliminates those distortions with non-stock op-amps, but also increased the dynamic range of the amplifier, even on the stock OPA2227. I didn’t use anything fancy here, just a plain 12V wallwart from my Hewlett Packard Printer re terminated to the proper 1.3x3x5mm DC connector. The JDSLabs Cmoy accepts a range of DC power adapters from 9-24V DC, either linear/switching or regulated ones. Seeing that DC Power adapter costs as little as $5.93 from DigiKey.com, it’s probably a good idea to have one around because not only does the 12V external supply gives a better dynamic range, but you can run the amplifier 24/7 without worrying about replacing batteries. You don’t need to unplug the batteries when using a power adapter (what a nice convenience!), but you need to plug the adapter when the amplifier is OFF.

Replacing the stock op-amp to the OPA627 improved the sound, though not by a large margin. A tad better micro detail, and a more weighty lower bass region, though soundstage was not as spacious as on the OPA2227. Another op-amp that I tried was the OPA2111KP, which performs at roughly the same performance level as the OPA2227, but with slightly different tonal balance than the OPA2227 and the OPA672. The OPA2111KP creates a more linear frequency balance that is less mid-centric, but improving the midrange clarity from the OPA2227/OPA627. With a Class-A biasing on the OPA627, the treble becomes very smooth and lush, something treble lovers should try. Class-A biasing is not a recommended configuration if you are using the amplifier without an external DC power supply, as the power drain on the battery would be pretty rapid. Moving around the different op-amps, I really am happy with any of the three I tried: the stock OPA2227, OPA2111kP, or the OPA627 (class-A biased or not). The JDSLabs Cmoy manages to give out a solid and musical presentation regardless of which of the three op-amps I use — though at the end I do think that the stock OPA2227 is my favorite out of the bunch (probably why John shipped the Cmoys with these).

Another thing that I discovered is that the JDSLabs Cmoy is very revealing of the original source. Some amps are not as transparent, and this makes source upgrades to better players like the Hifiman HM-602 less audible. But with the JDSLabs Cmoy, that congested midrange out of the Ipod Classic’s DAC always shows itself very clearly, making the HM-602 a much better player for pairing with the Cmoy.

STOCK BUILD VS LOW-Z CONFIGURATION
Comparing between the standard build version and the low-Z version with double TLE2426CLP, I did notice that the low-Z version handled my 32 Ohm MS-Pro better at loud passages, where the standard build distorts earlier — but this was at extremely loud levels. When I using the more average headphone such as the ATH M-50, HD650, HD800, or the HD598, or even the JH16Pro, I find the standard build version to give a more spacious and open sound, and this was the version I prefer for most of my listening. I am not sure if the difference was caused by the op-amp’s performance at the different gain levels (Gain 6 vs Gain 3), or the different components used to populate the boards, or perhaps because of the addition of the extra TLE2426CLP on the low-Z version. Anyway, I’m sure that John can give a better insight into this, and perhaps even make a low-Z version while still retaining the same sonic performance of the stock build. John mentioned that he is able to do 200+ different types of customization, so I’m sure that the choice is plenty. But if you’re in doubt, just order the stock build version, as I never really had volume control problems (though the range was a bit limited) even with the JH16Pro.

BASS BOOST SWITCH
The bass boost switch can be found when you open the lid of the case. It’s a toggle switch, and it adds a solid boost to the bass that extends quite low. It’s one of the better bass boost I’ve heard, as many bass boost often just lingers around the midbass area, while others tend to lose control of the bass. The bass boost on this amp actually goes fairly low, and the boosted bass remains fairly tight. It does color the bass area a bit and makes the frequency balance less smooth, so I actually use the JDSLabs Cmoy without the bass boost OFF mostly.

Slightly shorter and narrower footprint makes a nice stack together with the Ipod Classic 120GB.

 

JDSLABS CMOY VS PREMIUM BRANDS PORTABLE AMP
One of the thing that people always wonder is how good these Cmoys are compared to the premium brand portable amps. I no longer have most of the amplifiers I reviewed on the Portable Amp Shootout, but comparing the JDSLabs Cmoy to the HeadAmp Pico Slim (with the JH16Pro) reveals that though the Pico Slim has better micro detail, the JDSLabs Cmoy is more spacious in the soundstage. Also comparing the JDSLabs Cmoy to the Ibasso PB2 (single ended) out to the HD800, I found that the tonal balance and the overall sound is not as smooth on the Ibasso compared to the JDSLabs Cmoy. Of course there are other differences such as tonal balance, presentation, or the accuracy of the digital volume control on the Pico Slim, or the power output of the Ibasso PB-2. But for the general headphones out there without any specific power demands, I think the JDSLabs Cmoy can hang out with the general crowd of the premium amps.

END WORDS
When I emailed John asking about his Cmoys, I was merely looking for a Cmoy that I can recommend to the Headfonia readers: a Cmoy with a good build quality, good sound, and at a good price. But after spending time with the JDSLabs Cmoy, I was truly blown away with the sound that I’m hearing. Not only is this one of the best Cmoy I’ve listened to, but the sound is actually very good that I know other people would be blown away when they listen to this $60 amp. It is a really good amp, and I recommend it wholeheartedly.

Extra Documents:

 

System used for review:
Headphones: Sony PFR-V1, Audio Technica M-50, Sennheiser HD598, HD650, HD800, Beyerdynamic T50P, Alessandro MS-Pro, Superlux HD440, Jays Q-Jays, JHAudio JH16Pro
Amplifiers: JDSLabs Cmoy Normal build, Low-Z build, HeadAmp Pico Slim, Ibasso PB-2
Source: Hifiman HM-602, Ipod Classic

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  • Franz

    hey mike,

    can you compare to ibasso t3? tia

    • Anonymous

      Hi Franz,
      Sure. Still haven’t found an Ibasso T3.

    • http://www.facebook.com/people/Alphonse-Clemente/543875183 Alphonse Clemente

      I second this

      • Anonymous

        I have gotten the Ibasso T3D and there is simply no comparison. The JDSLabs is far far better. Sorry guys.

        If you want an alternative from the T3, something similar you can check out is the Soundmagic A10 amplifier. The sound is quite better, and actually quite enjoyable — though it is still one step below the JDS labs.

        I am looking for the Biosciencegeek Cmoy now, want to make a comparison with.

        • http://www.facebook.com/yH.dTheo Chiang Yi Herng

          wert!?!? damn!! who wants my t3d? xD

          • Anonymous

            Yep, that’s right.

  • Anthony the newbie

    there re so many empty space left, why dont he use two 9v-batteries instead of 1 or change to smaller tin

    • Anonymous

      I’ve forwarded your question to John @ JDSLabs. Let’s see what he has to say.

      I bet you can ask him to customize your Cmoy build to use two 9V batteries.

    • http://twitter.com/jdslabs JDS Labs, Inc.

      The PCB has provisions for dual 9V connectors (one of the many possible customizations): http://www.jdslabs.com/diy_mods203.php

      However, two 9V’s are an extremely tight fit in the tin. This makes it a challenge to change the batteries, not to mention the higher cost and weight of an extra 9V.

      • Anonymous

        Thanks, John.

      • Anonymous

        I just read the modifications page.. Excellent, excellent stuff there!

      • Anonymous

        John,
        I measured the DC offset from my Ipod classic and came out with 7mV for one channel, and 2mV for the other. I think it should be okay to take off the input caps?

        • JDS Labs, Inc.

          7mV is high for an iPod. I image this figure drops off after a few seconds of measurement, but yes, this is reasonably safe for a low gain amp (3-4x).

          • Anonymous

            John,
            I was thinking about this issue the other day, but I feel that it should
            be relatively okay to take the chance. I mean, say the amp is feeding a
            1 Volts signal to the headphones, .007 Volts of DC offset should be
            quite *minor* in comparison, am I right?

            And again, I haven’t seen a scientific study proving that a DC offset
            upwards of 20mV (which is the general consensus for a safe limit) to be
            damaging to headphones.

            What do you think?

            • http://twitter.com/jdslabs JDS Labs, Inc.

              Yes, 7mV is nothing to worry about; even 20mV is fine.

              However, you have to factor in the amplifier’s gain. At a gain of 6x, source DC offset grows to 42mV! But again, the iPod’s offset likely settles down to 0mV as it is measured (at least ours do).

  • http://blog.jovien.biz Jovien

    Ahaha, the world of Cmoy :-) I’ve build my own RA-1 like, and it’s really pretty. But I noticed that it has a tiny lack of punch imo.

    • Anonymous

      Yep. A little lack of punch is common on Cmoys.

  • Anonymous

    thanks for the review mike!
    actually i’d just purchased two PCB from JDS Labs and a bunch of parts in anticipation to try to build a couple of these myself!

  • http://twitter.com/audiohub Audiohub Singapore

    I built one.
    I change out the output caps at the headphones out to sprague and used opa2227.
    Awesome stuff.

    • Anonymous

      Nice, Louis.

      • Guest

        I would love to read a comparison with the CMOY from biosciencegeek (sells via ebay too), whose amps are $49 plus $6 shipping. Also very high quality and excellent sound, but rather than the bass boost from JDS, BSG uses a hi and low gain internal jumper. I now have the BSG CMOY and like it alot. But I also recently purchased a Leckerton slimline UHA-4, which offers an excellent amp and a DAC, so I may sell or give the CMOY away (to a friend). Anyway, my guess is those are the two best CMOYs out there, so it would be great to read a head to head here on Headfonia.

        • Anonymous

          Yea, perhaps throw in a big Cmoy comparison. That would be fun!

  • Earfonia

    To complete your experience with CMoy, you should try 4 channels Pseudo Balanced CMoy, and hear how it drives Orthodynamic HE5-LE effortlessly :D

    • Anonymous

      What did you do to get the current the ortho demands?

      • Earfonia

        OPA552: 200mA output current, and high voltage power supply at +/- 28 volt.

        • Anonymous

          Nice.

          How much of a voltage swing would that give, with the 28V supply and
          OPA552?

          Any other high current op-amp recommendations?

    • Stef

      What C-moy are you speaking about ? Where to find more information / buy it ?

      • Anonymous

        He is referring to a four-channel “balanced” cmoy (pseudo balanced, you feed the four channels with unbalanced signals) that he just built recently.

  • http://profiles.google.com/yoav.tzfati yoav tzfati

    Hey mike,

    How would you compare the JDS Cmoy + a stand alone dac (alien/Behringer UCA202/m-audio transit/muse…) against the Fiio E7 driving the Superlux 668B?
    I thought it would probably be a good synergy because 668B have a little bit of recessed low mids and I like warmth.

    Thanks!

    • Anonymous

      Yes the Cmoy should be a good pairing for the HD668B. I haven’t compared the Fiio E7 with the Cmoy yet, perhaps I can update that comparison later..

  • Anonymous

    I googled “JDSLabs Cmoy” and found many good reviews on this amp.

    I also discovered that wwenze has written extensively about RMAA measurements and op-amp rollings on this guy.

    Here is the concluding paragraph:
    “Engineering is the art of compromise, and this amp did it right. Don’t want output capacitors because they audibly and measurably add distortion, check. A TLE2426 instead of a bad resistor divider in order to avoid output capacitors, check. No need for extra current capability via ground buffer and certain op-amps (you can’t do it without either), saving costs, check. The numbers don’t lie, and this thing is perfect for most sane situations as a portable headphone amplifier. Sure, you can get better performance by paying more, and worse performance while paying less. But you don’t really need higher performance, and you shouldn’t stand for worse performance since it is easier to design an amp that performs better than a DAC (that includes portable players and soundcards – anything doing digital-to-analog conversion), so the amp should never be the bottleneck. And this thing smacks right at that point. Getting the job done right at the lowest price. Okay, maybe not really, I would’ve wanted slightly more current. But then again, that’s the op-amp’s fault.

    So unless I find an amp that either 1) achieves the same performance for less money, or 2) achieves better for the same money, this thing will be at the top for value. And with measurements of other amps hard to come by, there is a lack of evidence to bring this guy down.”

    http://wwenze.blogspot.com/2011/03/jds-labs-cmoybb-v203-review.html

    This discussion on Head Fi also makes want to go out and find a Bioscience Geek Cmoy:
    http://www.head-fi.org/forum/thread/370545/jds-labs-cmoy-amp-vs-biosciencegeek

  • http://www.facebook.com/profile.php?id=666158607 Dhani Nugraha

    Mike, I listened to the iPod touch + JDS Labs CMoy (w/ class-A biased OPA627AU) + v-Jays, and I must say I’m surprised with the way this CMoy opens the v-Jays up. The v-Jays now has a very good separation and air to it, with more pronounced details, and smoother midrange. Acoustic rock/blues (eg. Eric Clapton, John Mayer, Damien Rice) excels with this setup. you should try it! :D

    • Anonymous

      Nice! I kept on wondering what’s up with the class-A biased OPA627AU
      though. The OPA2227 sounded better to my ears on the JDSLabs.

      • http://www.facebook.com/profile.php?id=666158607 Dhani Nugraha

        If my memory serves me right, in this CMoy, the 2227 sounds somewhat wider than the biased 627 but a tad darker. And yet, the 2227 sounds more musical than the biased 627. I wonder why…

        • Anonymous

          Damn you’ve got a photographic audio memory!

  • Anonymous

    Hm, I wonder how the upcoming Fiio E11 will match up to this? It’s also $60, so it should be interesting to see how they compare.

    Also, have you had a chance to check how much GSM interference this CMOY receives? Fiio delayed the E11 a few times trying to minimize that.

    • Anonymous

      Yes, it will be interesting to see how it compares to the E7.

      All the portable amps I have reviewed are not immune to GSM
      interference, including the expensive ones I reviewed in the shootout.
      So i stopped testing. :)

      • JDS Labs, Inc.

        To chime in here, there are ways to audibly eliminate GSM interference. We’re working on a high performance amplifier and have considered implementing such circuitry. However, and this is a BIG however, it cannot be done without impacting audio quality! Perhaps FiiO’s found a way to *minimize* the impact.

        GSM filtration circuitry also worsens turn on/off transients. These pops must either be ignored, or even more circuitry must be added to achieve perfection! My personal stance [JDS speaking]: Forgo GSM filtration. This is the simplest and most cost effective way to maintain a pure audio signal.

      • Evin Discreet

        So I guess you have made up your mind in comparison to the E7 AND the E11, Mike. Just wish it was a little more practical in terms of charging/recharging, DC power.

  • Anonymous

    I hope to receive the Biosciencegeek Cmoy and the Ibasso T3D amplifiers soon.
    Please stay in tune for a comparison.

    Looking at the Biosciencegeek eBay page, I think it will be most interesting to compare how the PCB approach (JDSLabs) compares to the point-to-point build of the Biosciencegeek.

    “A signature hand-finished black custom board is manually assembled to ensure the highest quality construction. It has a slight irridescent purple cast to it that really looks nice permanently fixed in the case. There are no stray wires flopping around to pick up stray signals or degrade the signal path. Solid point-to-point wire joints (NOT the micron-thin traces used on mass-produced cheap commercial printed circuit boards) connect components for optimal signal transfer and reliability. Although it would have been easier for me to just have some inexpensive PCB’s made (yes, I did experiment with that at one point; I’m a scientist :), my experience has shown those boards’ reliability and conductivity are no match for hand-built quality. I was recently asked by a customer to inspect and repair a PCB amp built by a competitor and can say with total certainty that I vastly prefer the quality of my design and construction methods (and so do my customers).”

    http://bit.ly/g8JQZu

  • Anonymous
  • Questa

    You should also try the penguin :D

    • Anonymous

      You have one for me to try out?

      But I dont think Robert is still making the Penguins, is he?

  • http://profiles.google.com/yoav.tzfati yoav tzfati

    Another question… how is its vocal presence?
    I generally want it to sound as close to my eq preset as possible. (I included a pic)

    • Anonymous

      surprisingly, I think the sound is actually pretty close to your EQ preset except for the small bumps at 4kHz and at 32Hz. It’s a lower midrange centric sound.

      As for vocal presence, it’s just okay. Not too distant but not too forward either. If you want it more forward you need to bump the 1kHz and 2kHz up a bit.

      • http://profiles.google.com/yoav.tzfati yoav tzfati

        Thanks! I can live with the ok vocal presence because a lot of my music is instrumental anyway. just wanted to make sure this cmoy is close to perfect for me, because I also really wanted to try and build one myself and this looks like its a little complicated, and also costs more to build, according to the JDSlabs sight (but sq is #1 priority and I’m definitely getting it!).
        oh and btw, according to the garage band eq presets the vocal presence and forwardness is closer to 4k, which is the main reason I bumped it on my eq.

        • Anonymous

          Awesome. I personally like buying finished amps, although I also do DIY a fair bit. Less hassle, spend more time with the music.

      • http://www.facebook.com/thrkimaa Arjun Jamil

        How does this fair against the fiio e5?
        Also,please check the HD595 vs HD 558 vs HD 598 thread. I have some questions i gotta ask you.
        Thanks.

        • Anonymous

          Much, much better than the Fiio E5.

          Answered your post on the HD558 article.

  • Pingback: Headphone amp project- just finished - AudioAficionado.org

  • Anonymous

    Well, guess what. It comes sooner than I expected.

    JDSLabs Cmoy now does recharging.
    http://www.jdslabs.com/item.php?fetchitem=ChgAdpt

  • HD280Pro

    Mike, I just wanted to say thanks for the great review. I’ve been on the fence about getting a headphone amp for some time to give my trusty old Sennheiser HD-280 Pros a bit more pep, and for $60 decided to give the JDSLabs Cmoy a shot… Especially after seeing that John at JDSLabs originally designed the amp to give his HD-280 Pros more bass.

    All I can say is “wow,” what a difference. I use them mainly for music and movies/games, and the JDSLabs Cmoy totally opened up my cans. The bass boost also brought in a fantastic low end that was lacking before while at the same time adding a richness to the sound.

    • Anonymous

      Nice.

      I love it when people get good sound out of the gears that I review.

      Thanks for sharing.

  • Phantompain

    Just wondering if this amp would work with westone 2 iem. I heard they tend to hiss as their low impedance earphone which do not require using an amp. However im just curious if its possible to improve the sound quality as my Ipod touch 2nd gen is pretty underwhelming.

    • Anonymous

      I think what happens is probably the westone sound not working to your liking. The W2 is very easy to drive and shouldn’t require an amp at all.

      • Phantompain

        I love the sound of the the westone 2 its just that i was wondering if it would improve the sound quality though. thank you for the advice :)

        • Anonymous

          While the JDSLabs have been one of my favorite amp, I doubt you’ll need
          any amp to make the Westone 2 sings. If you do get the JDSLabs Cmoy, the
          only difference you’ll get is additional bass from the amplifier’s bass
          boost. :)

          • Phantompain

            I see hmmm thanks again for the help and your wonderful reviews :)

  • bookaboo

    hi mike,

    great review. i am using a ra1 clone with a opa627 on a browndog adaptor with my hd650′s. have you heard the ra1 and would a 18v jds labs cmoy be a better option with the opa627 or stock opa2227.

    thanks
     

    • Anonymous

      Roughly it should be similar sounding. The only differences that matter
      is perhaps the build quality, enclosure size, etc.

      18V should improve the sound much more, and currently I think the
      OPA2227 is better than the OPA627 (I’ve been a big fan of the 627 for a
      long time, but after I discovered the 2227 I rarely go back to the 627).

  • Dookie182

    mike,
    did you finaly had the chance to get a Biosciencegeek Cmoy? I’m really looking forward to a comparaison. Even if I guess that you could be fine with either of them, I guess the human soul always want to know wich one could be the relatively “better” anyways?
    kindest regards

    • Anonymous

      Hi Dookie,
      Sorry I ended up not being able to find a Biosciencegeek Cmoy. I don’t
      know if this will help, but I’ve listened to a lot of other DIY built
      Cmoy during the time of this review and the sound quality is more or
      less the same as the JDSLabs, even on some Cmoy that use boutique
      components. I would say therefore that the performance is somewhat
      limited by the design of the Cmoy and that the JDSLabs is among one of
      the best Cmoy out there.

  • y2j

    Hi sir, how does this pair up with the hd25 and rock tracks? Thanks!

    • Anonymous
      • y2j

        Hmm, I can’t source the PA2V2 from where I’m from. Any other suggestions sir? Thanks!

        • Anonymous

          You have to send Gary an email directly. gary@electric-avenues.com

          • y2j

            Alright sir. Thanks! :) Will email him later. I’m kinda bummed out by the PA2V2 form factor though.

            • Anonymous

              Yes, it’s not the most modern design out there, but some people love the
              old-school look. :)

        • Anonymous

          If you really can’t get a hold of the PA2V2, the JDSLabs is also a good
          amp and I’d just get that instead.

        • Anonymous

          If you really can’t get a hold of the PA2V2, the JDSLabs is also a good
          amp and I’d just get that instead.

  • AnaIvanovic

    Hi, may i know if this will sound good with the westone um3x? I’m quite keen on getting this amp but i’m still not sure how will it improve the sound of my iem. :)

    • Anonymous

      Hi Ana,
      The JDSLabs will help to give a more expansive soundstage on the UM3X.

  • Applevalleyjoe

    Hi, excellent review! I’m curious though…how does this compare to the many CMOY’s on the internet? Do you recommend any others or is this one an exception?

    • Anonymous

      There are many many different Cmoy builds out there, and so it would be
      quite difficult to compare them all. The JDSLabs is among the nicest
      sounding Cmoy I’ve heard though, even compared to custom builds with
      boutique parts. And with a solid build quality and support from JDSLabs.
      That’s why I went and recommended it.

  • max

    hi, thanks a lot for your review! it was very useful for me! ..only a problem, after reading i’ve a small question: what is the best amp for lissening to rock music (from the 60s to our days: bands like beatles, kinks, monkees to queen, deep purple and muse, radiohead, beck, arctic monkeys ecc.. :P ) with a pair of sennheiser hd598 between JDSlabs Cmoy and PA2v2?
    btw, i’ll use it as a desktop amp..
    i’m searching on the web for a week now, and haven’t found an answer, sorry for the specific question.

    • Anonymous

      You’re welcome, Max.

      Do you find the HD598 to be a bit light on bass impact? If yes, then I think the JDSLabs is the better choice between the two.

      • max

        thanks for the answer! i’ve ordered them yesterday, they’ll arrive next week.. i’ll lissen to them and finally make a choise! :P
        ..JDSLabs Standard Cmoy. right? not the z-low one

  • nawawi

    Hey mike, could you comment on the Fiio E11, Pa2v2 and JDSLABS cMoy on the following set-up? I would like to open up the soundstage and make instrument seperation better.

    iPod video 5.5G -> LOD -> Hifiman Re0/ Fischer Audio Eterna

    • Anonymous

      Go with the JDSLabs cmoy.

      • Nawawi

        Thanks mike!

        • nawawi

          Just pulled the plug on these the other day, cant wait for it to arrive!

    • Anonymous

      Go with the JDSLabs Cmoy with the stock op-amp.

  • http://twitter.com/DodgersKings323 DodgersKings323

    I see an ipod owner is here, i was wondering which player would be better using the LOD; Sansa Fuze or Ipod 5Gen?

    • Anonymous

      Sorry, never compared the line out quality of the Fuze to an Ipod.

  • http://www.facebook.com/profile.php?id=100000222897353 Shane Revis

    Would I get better or worse sound from my AD700s if I used this Cmoy with the headphone-out of my Zune 120?

    • Anonymous

      Hi Shane,
      You would get a better sound, yes.

      • http://www.facebook.com/profile.php?id=100000222897353 Shane Revis

        Wouldn’t the music be going through two different amps? The internal one, and then the Cmoy? That would distort, right? Would it be worth $90 (including everything) for the sound improvement?

        • Anonymous

          Yes it would pass on two different amps.. that’s why a player with a line out is better.

          I don’t think it would distort though. As for the dollar to improvement ratio, I can’t say. One man’s $90 is different than another’s $90, but the JDSLabs is one of the best bang-for-the-buck amp around.

          • http://www.facebook.com/profile.php?id=100000222897353 Shane Revis

            Why is it so impossible for someone to make an LOD for a Zune 120? There are LODs for the Zune 8 GB and the Zune 30 GB on Ebay. I don’t understand it…

          • http://www.facebook.com/profile.php?id=100000222897353 Shane Revis

            Why is it so impossible for someone to make an LOD for a Zune 120? There are LODs for the Zune 8 GB and the Zune 30 GB on Ebay. I don’t understand it…

          • Anonymous

            How is the Zune 120 any different than the 30 or 8 GBs? Sorry not too familiar with the Zune models. 

          • http://www.facebook.com/profile.php?id=100000222897353 Shane Revis

            I don’t know. I didn’t think that it was different. A Head-fi member tried the Zune 8GB LOD cable with his 80GB and it didn’t work. Are there any audiophile portable CDPs that have a pure digital line-out? 

            • Anonymous

              Hi Shane,
              Many of the portable CD players have digital out. You just have to go out and find one.

  • http://twitter.com/DodgersKings323 DodgersKings323

    WOW!! Ok so this is the story, i busted my KSC75s trying to recable them, DOH! I will get my Grado’s shortly so for now i’m mainly using my MEE M9 $20 IEMs and AD700s, this amp is blowing me away!! Everything sounds so full! And this out of the headphone jack from my Samsung cell phone :D
    It’s like the band is playing around me at times, i can’t imagine that things actually get better!!
    Worth every penny! Now i have to find one of those rubber bands people use to hold things together.

    • Anonymous

      Glad to hear that… I’m happy whenever people get a good enjoyment from their gears.

      More people should really give the JDSLabs a try. There is a reason I made so many recommendations for it.

  • Luka Sabo

    Thanks for the review Mike! I’ve been looking for a portable amp for my MS1i fones. Would this amp improve the soundstage of my babies? I listen to Indie, Rock, Alternative… Thanks in advance! :)

    • Anonymous

      You’ve come to the right place because yes this amp would improve the soundstage of your MS1i :)

      • Luka Sabo

        Thank you, kind sir! Your help is indeed appreciated.
        And remember, let the interwebs be with you!

        • Anonymous

          Thanks Luka!

  • Applevalleyjoe

    What’s the story on JDS’s new amp…any further progress?

    • Anonymous

      Yes, here is the last email from JDSLabs:

      We’re staying busy! C421 is on track for release to reviewers in October. In case you missed it, I posted a preview of the enclosure in August. Enclosure samples were approved last week, so we have about 3-4 weeks to go, plus final assembly and testing. There’s one minor holdup: I’ve demoed two prototypes to a few listeners, one with an AD8066, and the other with an AD8620 as the main opamp. Both are excellent in C421, so it really comes down to user preference. The AD8620 is more analytical, while the AD8066 is known for its emphasis on bass (fine quality, not amplitude manipulation, of course). Thus, we may release the amp with several opamp options. The original goal was to create an option-free amp. However, it’s impossible to please everyone with one configuration.