Idea for DIY Headphone Amp

[MikalCarbine]

Lately I've been going through this audiophile phase (been wanting to mod my DT770's, change soundcard and all that good stuff) and I've been thinking of making a DIY amp. I posted on head-fi.org forums for some good suggestions but I might just stay cheap and make a decent CMoy amp. My idea is to not make it portable though. My DT770s are anything other than portable and I don't use them with my ipod much. Since I only use them with my computer, why bother making the amp portable? Also, why bother having another power cord to run if it is going to be for my computer. I was thinking of making it run of the 12v rail of my PSU :D

This would be possible right? I would need some sort of hollow 5.25" bay/hobby box in order to do this, any suggestions?

[Andrew LB]

CMoy amps are ok sounding but to be honest, i'd look into building a headphone amp a step or two up from it. I ended up getting rid of my CMoy after only a couple weeks.

[MikalCarbine]

I actually already though of that, through my research I came across PIMETA, what do you think of that? It is a little more complicated but would work with my situation

Is your sig a custom built tube amp?

[Andrew LB]

^^^ The PIMETA is a much better design. I've heard a few variants and they sounded quite nice even with the super high impedience of my Sennheiser HD580's (600ohm).

As for my amp, it is an Antique Sound Labs MG-Head OTL tube amplifier. Here is a high resolution photo of the amp. This one is not mine though.

http://sites.estvideo.net/lenainrouge/Hifi/MGhead/2005_1118_225000AA.JPG

[MikalCarbine]

Looks nice, I assume that sounds great ;)

Looks like I'll be going with the PIMETA design, I showed it to my friend and he might be able to help me out with mods to the circuit to fit my needs ;)

What case would you recommend to use for this? Ideally I would like it to be in my 5.25" bay but I'm willing to make it external

I'll post results or any questions that arise

[Andrew LB]

^^^ I would highly recommend against installing a headphone amplifier INSIDE your computer case. There is far too much RF noise which will wreck havoc on your sound quality.

Always keep your sound card as far away from your video card as possible and i've been reading on Head-Fi.org that many audiophiles are actually putting a layer of a special material which keeps the RF noise generated by video cards and other components from interfering with your sound cards components.

I always recommend that headphone amps be external with a dedicated power supply if you can afford it. If not, purchase a proper battery backup system for your PC which conditions the power used by the computer because if your headphone amp is on the same circuit as your computer, you will definitely pickup noise if your computer does not have this. I not only have a line conditioning battery backup for my computer, but i've made it a point to power my headphone amp from a different circuit in the room. Unfortunately most people wont have this option since the vast majority of houses don't run separate circuits in a single room.

[MikalCarbine]

Thanks for the info, didn't notice you ever replied either (damn user CP)

With that being said, I might just buy an external amp

I do have a UPS that conditions power too :up:

[ooeric]

make yourself a PPA, i use a maxed one with glassman buffers and crap( the works )
i drive my hd650s easily. not even 15% of the volume knob. is loud enough for me

only thing about ppa. take your time. its quite a big step up from making something like,, lets say a cmoy or pimeta.

[sc00p]

Try to find a kit with adjustable crossfeed-filter...
...but be careful about that; once you taste of it, cannot live without it IMO.

Did mine long time ago... damn, it's been lost over 10-15 years LOL