[Kibble Fat]

Hello,

I would like to get into building my own amp(s) to use with my 6G ipod classic and Nuforce NE-7M IEMs. Now, I won't be straying from IEMs any time soon, so I could care less about gain. I would, however like to get a clearer sound as it seems a bit muffled to me as is. The headphones do a decent job of extracting bass from the ipod and the high frequencies are ok as well. I would just like a crisper sound, could even stand bringing out the highs a lows a bit. I was looking at the CMoy which seems like a good place to start. Would I be able to fine tune the SQ to my liking, or is it predominantly just going to boost the volume?

I have quite a bit of soldering experience, a year of circuits classes, and would probably have some fun with the packaging/tetris aspect if it's called for.

Let me know what you think!

Eric

 

[Kibble Fat]

Ok, I realized after I posted this that no one would want to read it, let alone reply to it. Completely understandable. I'll go do some more reading..

 

[ThePredator]

As much as it seems DIY saves money, it really doesn't. Even forgoing the tool cost, the addiction will run up your paycheck quicker than you would believe.

Unless you add bass boost or similar the cmoy won't really help with EQ that much, and it probably won't make much of a noticeable difference for IEMs.

One thing you can look at is modding your iPod, if the 6G is moddable it is supposed to be more than a subtle difference. There is a thread in this forum named "diypod" I believe that would have the necessary info.

[EDIT]: Even so, the cmoy is a fun project and it will come in handy if you want have or want to try out some full size headphones.

 

[Kibble Fat]

The 6G is deemed "un-modable" by people who do that sort of stuff. I think I'll try Tangent's Cmoy. Once I figure out exactly what frequency response I'd like, I'll try designing my own circuit around the Cmoy. Time to find my old textbooks!

 

[Forte]

Tangents Cmoy guide is a great place to start and the SQ can be tweaked by changing the opamp, use an IC Socket and you can easily swap opamps in and out.

It would help to know your budget and if you want portable or not.

For a portable amp that is a lot better than a Cmoy check out the The Mini³ Portable Stereo Headphone Amplifier you can build it with a gain as low as 2x.

If portability is not required then maybe the JISBOS - overview may be worth looking at. I believe you can use these as a headphone amp without a voltage gain stage.

 

[Kibble Fat]

looking for portablity, low cost, and customizability. The IC socket sounds good to me! I think I'll forgo the gain adjustment knob just because it's one more thing to get messed up in my pocket. I'll buy a few more resistors to play with for sure.

I tend to like jazz pre-sets (more pronounced highs and lows). Is there another op-amp besides the one prescribed by Tangent I should pick up right off the bat? I'm leaning towards an Analog Devices AD823

One more thing: Is a pcb going to have noticeably less noise/variation in the sound or is that mostly just hype? I promise to keep all the wires as short as possible...

 

[Forte]

Never tried any other opamp in my Cmoy than opa2134 so I can't say, just built it to see if I really could build an amp before committing to more expensive projects. If you haven't found it already Tangent has a page on choosing opamps Notes on Audio Op-Amps and it sounds like AD823 may be a good choice for you. You could also try the search function, there are a few threads on the subject here IIRC.

PCB shouldn't make much, if any difference with a design this simple IMO.

Are you planning on using the headphone jack on your iPod or a LOD? Amplifying the headphone out probably won't yield any benefit in SQ and if you use a LOD you will probably need volume control. If you haven't done so already consider changing your music to lossless, the iPod classic has plenty of room for larger song files and it is a huge improvement.

 

[Kibble Fat]

I've got a number of lossless albums with more to come. Yes, I was subconsciously thinking that I would use the LOD! Good catch Forte