Review: cMoy Headphone Amp Bass BOOST Edition

[HeadphoneAddict]

I bought one of these to play with, and got it yesterday.

The sound is quite fun, adding punch to the ipod's output. It plays more than loud enough, without clipping. Bass boost is very smooth, withOUT unsightly coloration in the mid-bass. It is also very quiet, without background noise. Too quiet as a matter of fact for some (or many) audiophiles.

When listening to "Jazz at the pawnshop" at 192kbps on an 8gb Nano with my Ultrasone HFI 700 headphones, it sounds just like the recording was made in a studio. The problem is that it is a live recording made in a small club. With the Tomahawk Amp and the same source and headphones it sounds like a live recording.

With the cMoy the ambience/reverberation between notes or after the strike of the drums, etc... seems to be missing. Almost like the threshhold for letting quiet sounds and secondary harmonics pass through is set too high, i.e echo and resonance from the environment.

I will let this burn-in once I am done burning-in my D1, and report back in a few weeks with changes and improvements that I hear with this issue. I may also try it using my H120 optical+D1 as the Transport/DAC, instead of with an ipod's built-in DAC.

However, for casual listening with a nice set of headphones it will definitely rock out. It is a $39 amp that sounds like a $100 amp, and I have no regrets buying it as a spare. It should get better with time.

The seller is also very good at communicating about your needs and accomodating those needs, or customizing as needed. I got a gain switch hidden internally, and the LED brightness custom tailored. All I need now is a AC-to-DC power supply and rechargable 9v and I'm all set to not have to buy 9v batteries.

[HeadphoneAddict]

Previously I complained about the ER6i earphones being harsh, and even shrill with piano notes, but with good detail and bass. Because of that I have burned in my ER6i for 86 hours so far (was told I don't have to) and as a result they are indeed less harsh and have more bass. Also, this is with the Shure Black Olive foamies installed instead of any of the flanged or foam tips that came with the ER6i.

Since the ER6i actually seem smoother through the new iBasso amp than the Tomahawk, so I tried them with the new "un-broken-in" Altoids cMoy with bass boost. The cMoy amp really seems to tame the ER6i and make them more enjoyable. So, I am going to spend more time burning this cMoy sooner than later, and use it to sleep with music every night.

I'll continue to test the ER6i and the cMoy as I go to bed each night. I have to because today I gave my E2c "sleeping phones" to my lawn guy since I discovered he was using sennheiser open ear buds to listen to music over the loud gas mower (okay, so he offered to cut my lawn 4 times for them).

So, I think this little cMoy is going to mature nicely. The guys at work already want one, because barfing $300-400 for a RSA amp isn't agreeable to their wallets. One of them also wants to trade his E3c for my E4c but that isn't gonna happen He might not want mine after he tries his with a cMoy-bass-boost amp. We should just call these a C-B-B amp.

[1Time]

I bought this cMoy on eBay today to use with my HD580 and Chaintech AV-710, plain with no LED for $45.95 shipped. I just wanted something cheap and the info in John's eBay listing intrigued me. Then I came to Head-Fi and reading this thread sold me.

[1Time]

Originally Posted by HeadphoneAddict

We should just call these a C-B-B amp.

I suggest calling it a cMoyBB.

[jewman]

I'm thinking of buying this amp as my first headphone amp. I would be using it mostly with my UE SF3's and my h320. Should I buy it? Or should I save up some more dough and reach for the iBasso T2? If I should buy it, should I wait for the volume knob or not? I know it's a lot of questions, but I trust you guys can answer them all. Thanks!

[1Time]

Originally Posted by jewman

I'm thinking of buying this amp as my first headphone amp. I would be using it mostly with my UE SF3's and my h320. Should I buy it? Or should I save up some more dough and reach for the iBasso T2? If I should buy it, should I wait for the volume knob or not? I know it's a lot of questions, but I trust you guys can answer them all. Thanks!

You should buy it now because 1) you can benefit from an amp now, and 2) the cMoyBB is selling at an introductory price. You should not wait for the volume knob since it is not needed.

[SK138]

Wait until I have my modded iGrado balanced with senn HD650 stock cable and it will be one of the most "happy for your wallet" gear around

Originally Posted by ampjoy

CMOY balanced... Kinky.

[HeadphoneAddict]

I have to say I have over 24 hours of burn-in on the cMoyBassBoost and it is cleaning up very nicely! It doesn't sound anything like it did fresh out of the box.

Everything I listen to now has an improved sound-stage, the fine details that were being filtered out on the live jazz recording can NOW be heard, and the amp has plenty of power.

I have the optional switch that allows my Sennheisers to run more efficiently, and the other flip on the switch is the setting for my IEM's (just tell him what headphones you have when you order, and if you want the optional switch). If I play the PMX100 headphones with the IEM setting I can hear the amp running out of power - flip the switch and voila! it is clear as a bell. The IEM will play with either setting, but the Senn setting has less gain but also less hiss with the volume all the way down (maybe s/n ratio of at least 75-80db I'm guessing with the louder setting). The way I understand it, highly efficient headphones will show the hiss more but you can adjust the impedance (or gain I think) and that improves with a little less efficiency.

I also picked up a power adapter at Radio Shack so that when I listen to it at home I don't have to run the batteries down, and the amp disconnects the battery when it is plugged into the wall. I tested the alkaline 9v battery after 24 hours of use and it still looks close to a full battery; so it seems to run so well off an Alkaline battery that it doesn't need a charging circuit. I'd bet the battery is good for 75-80 hours.

It still isn't close to the RSA Tomahawk amp, but it is very impressive for the price.

[HeadphoneAddict]

Originally Posted by SK138

Wait until I have my modded iGrado balanced with senn HD650 stock cable and it will be one of the most "happy for your wallet" gear around

WHY DIDN'T I THINK OF THAT! Then they'd sound better than my PMX100 with all kinds of music, not just Rock

[MusicallySilent]

Yea about your cmoy balanced... you make me so very tempted to make a mini3 or cmoy or pimeta in a good case with a good power supply so both are in one case and try to wire it for a single volume pot.

[HeadphoneAddict]

You know, I had skipped over SK138's balanced post because I am not interested in doing that right now.

But, I went back and read it just now and realised that my posted observations on the sound quality and the progress or transformation over 48 hours are identical. It feels good to know my "ears to brain to mouth connection" in assessing sound works the same as with other people It also serves to lend more credibility to his post about balanced cMoys, that he really isn't nuts but acted on a great idea!

My observations are spread between three threads though - this one, the ER6i vs Super.fi 3 thread, and a new one I posted about head to head inexpensive altoids c;moy testing. I wish I could post the links here, but it is way too complicated on the Motorola Q smartphone, which with a 4GB SD card is now an excellent additional music source for me.

[SK138]

I should thank you for validating me. I was REALLY hesitant to post my findings about the balanced cMoy thinking I would be the laughing stock here at Head-Fi. I am not any "authority" when it comes to sound quality. I just know what makes me enjoy endless hours of music that I love. On that note, you did a super review

Originally Posted by HeadphoneAddict

You know, I had skipped over SK138's balanced post because I am not interested in doing that right now.

But, I went back and read it just now and realised that my posted observations on the sound quality and the progress or transformation over 48 hours are identical. It feels good to know my "ears to brain to mouth connection" in assessing sound works the same as with other people It also serves to lend more credibility to his post about balanced cMoys, that he really isn't nuts but acted on a great idea!

My observations are spread between three threads though - this one, the ER6i vs Super.fi 3 thread, and a new one I posted about head to head inexpensive altoids c;moy testing. I wish I could post the links here, but it is way too complicated on the Motorola Q smartphone, which with a 4GB SD card is now an excellent additional music source for me.

[blackinches]

The first two prototype PCBs arrived today. I'll make some layout adjustments and have the final PCBs in under two weeks.

However, I'm extraordinarily busy and one of the jacks I use is backordered until October. Thus, it may be a while before I can begin to sell these on eBay.

[HeadphoneAddict]

You might want to re-think the in/volume/out being that close together.

Some people have 3.5mm plugs that are too fat to fit into those jacks!

[1Time]

Originally Posted by HeadphoneAddict

You might want to re-think the in/volume/out being that close together.

Some people have 3.5mm plugs that are too fat to fit into those jacks!

I have 2 different 3.5mm to 1/4" adapters, one round and the other hexagonal. I put one in the IN and the other in the OUT to check this, and my guess is there would be enough room for the volume. My cMoyBB has the bass boost toggle where the volume would be. Maybe blackinches didn't count on anyone using larger than ordinary adapters.