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CMOY OPAMP 2227 Portable Amp Question

post #1 of 14
Thread Starter 

I just got my FiiO E5, but I'd really like to go to a CMOY. I found the CMOY OPAMP 2227 amps on ebay for a fair price and I'm sure they'll yield better results than the FiiO. I'm planning to get one that I can take with my with my phone for listening, but I've also used the FiiO on my desktop now and the difference is staggering. Would the CMOY be a decent little started desktop amp as well? I can't afford to spend 100 - 200 on a full fledged desktop amp and these little guys seem to get lots of praise. Thanks for any and all help you can provide!

Edited by Hexidecimal - 8/24/11 at 3:55pm
post #2 of 14



Yes, it will do that no matter the source. The only reason people get desktop stuff versus portable stuff is because a high quality portable amp is far more expensive and has way less power output than a desktop amp that doesn't have to run off a battery. You could get very powerful amp for your desktop for dirt cheap if it didn't have to have a battery. But if you want something portable, the CMOY is great. And again, it's application is endless so long as it's plugged into headphones. Doesn't matter if you have it plugged in from your phone or a computer. So long as you feed it a signal, you're good. Just keep the batteries up.


Very best,

post #3 of 14
Thread Starter 

That's sort of what I figured, but I thought it'd be best to ask the experts. The CMOY it is, likely I'll use it more at the desk anyways. Thanks for all your help. Off I go to get a CMOY.

post #4 of 14
You could run DC to it and put some big filter caps in it in place of batteries and actually have a desktop version of it. To really benefit though, they'd have to be decent caps, and the supply should be at least half decent. Otherwise a battery is going to provide much cleaner power, and the sound difference would likely be worth the battery costs.
post #5 of 14
Thread Starter 

I was going to ask if anyone has converted one of these to a desktop style amp with a 9V DC power adapter. The basic principle seems easy, but is there a tutorial somewhere on how to do this? An adapter is cheap, but I assumed it would be a bit more complicated then running red to red black to black and plugging it into the wall. Any help converting it to a desktop amp would be awesome.

post #6 of 14
That's about it really for the simple approach.

OPA2227 runs up to 36V (split rail) though, so you might want to supply it more power in a desktop form.

There are plenty of ways to do the supply:

Straight DC supply
DC through filtration and regulation
AC through rectification, regulation, and filtration (the method I used on my Phono Preamp)
post #7 of 14
Thread Starter 

So if I got a 12v DC Power adapter, cut off the adapter end, split the connect out to red & black, then shrank and soldered it to the red black connections inside the tin it should work fine?

post #8 of 14
It should work just fine, yes. You could get the barrel socket that fits your 12V supply and wire it all up to keep it nice and clean (and portable, but that's not a goal of this modification afaik)

You might want to put some capacitors in between the supply and the power inputs though to help keep out anything that the supply itself isn't filtering out from the AC.

The space saved from removing the batteries would probably be more than enough to put some reasonably large filter caps in there.

Oh, and if you want to look into making this work, you could run it from a supply, but leave rechargeable batteries in it, both allowing portability when you want it, and the battery would act as a filter cap when running from a wallwart.
Edited by sml1226 - 8/24/11 at 6:31pm
post #9 of 14
Thread Starter 

That would be ideal to leave rechargable battery in it, but at this point I think I'd like to mod the one I just bought to run strictly on DC power, then buy a second one that is completely portable if need be. though I suppose I could get a 9v DC adapter and a 9v DC Battery pad, and avoid cutting the existing pad off, then just link the 2 pads together to run on DC, and put a battery in when I wanted the one to be portable. Correct?

post #10 of 14
Yes, that works. Tangent actually shows a couple of ways to run DC in the suggestions. One method is a DC jack and a switch to choose the supply source (battery or DC supply). A switched jack does the same thing automatically. You can use a 12V supply and Zener diodes... lots of options, but either the one you just mentioned, a splice, or a DC jack are your best choices though in terms of ease of use.
post #11 of 14
Thread Starter 

Excellent. A trip to my Radio Shack is in order as soon as my CMOY shows up. I'll be soldering the battery pad to a 12v DC adapter so I have the option of desktop mode, or portable mode from one CMOY, and probably picking up a second one in a couple of weeks to tinker with. You've been extremely helpful sml1226, and I appreciate it.

post #12 of 14
No problem. I looked into all of this before giving up and realizing I never take my cans that need amping away from bigger amps I already have here.
post #13 of 14

My CMOY from Biosciencegeek had DC functionality built in by default, I just needed to buy an adapter from Rat Shack. The battery is automatically cut out of the loop when the adapter is plugged into the amp.

post #14 of 14
Thread Starter 

Actually I saw a CMOY in the same tin I ordered mine in that had that function built in. I'm hoping I get lucky and mine has the same option built in. If it doesn't I've talked to a couple of guys at work who are going to help my install a DC adapter.

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