DIY: Headphone amp in a CD-ROM drive
Not that there is anything at all wrong with having a headphone amplifier prominently and obviously displayed on your desk, you may in fact work in an environment where leaving such a bit of easily pocketed hardware about is dangerous. (Okay, that's not very likely, but I'm trying.) Reader Gio Militano sent in his own DIY project to share, in which an out-of-work external CD-ROM drive is converted into a homebrew headphone amplifier that blends in to the beige boxes around your desk.
DIY CLASS A MOSFET HEADPHONE AMPLIFIER [DIYAudioProjects.com]
the latest
latest episodes
Good try. Certainly better than "Ever wish you had an amplifier that looks just like a CD-ROM drive? Gio Militano has finally made that dream possible."
Could someone with rather more electronic knowledge than I comment on how this differs from the CMoy pocket amp?
I can solder, but my theory is pretty lacking - is this essentially constructing your own op-amp?
Wow, now you can genuinely use it as a cup holder too!
Surely it would make more sense to cram the components into a 5.5" drive bay case and install it into the computer (and power it direct from the PSU)?
Alternatively, if you REALLY didn't want anyone to steal your headphone amp, it would be awesome to install one in a cinder block. I'm sure the mass of the concrete would flatten out quantum harmonic distortions, resulting in sonorous bass, crisp treble and rose-hip scented supersonics.
This is a pretty good project. The basic circuit is solid and should sound good.
OMG. There's a HUGE jumping spider crawling on my monitor....
Crap! I took my eye off of him to get something to scoop him up and now he's disappeared.
Theeeere you are! Under the inkwell...
How to capture this thing without hurting it? They have really good eyesight.
Back to the amp thing after I deal with this arachnid...
Joel, I love you. Another couple of minutes reviewing (or sleep) might have revealed to you that you missed inserting the word "wrong" in the first sentence.
Respectfully,
Pedantry, Inc.
ANYWAY...
The basic circuit is decent and should sound very good. It's also not particularly critical about layout or parts quality.
This implementation is well thought out and designed.
You couldn't install it directly in a computer without adding a power supply capable of delivering 10v - 20v at a reasonable amount of current, so there's no advantage there.
DIYAUDIOPROJECTS.COM is a good site with a number of projects tha tare well worth building.
I have added "wrong!" Thanks!
Could someone with rather more electronic knowledge than I comment on how this differs from the CMoy pocket amp?
The Cmoy amp is a simple implementation with a high quality Burr Brown operational amplifier for gain and drive. That unit can be configured to have voltage gain (increased volume) which is useful if the source isn't loud enough. The Cmoy amp is also a more difficult build because of the tight spacing of components. It's probably not an appropriate beginner project unless your other hobby is watch repair or similar.
The CD drive amp in this post does not have voltage gain. Its volume may be less than that of the source component. It does have a LOT of current drive capability. This is necessary with low impedance headphones like the Grados shown with it. I have Grado SR-80s and SR-60s. They need so much current that they will sound bad if the source component has a weak output stage. This CD drive amp will make a huge difference between some portable sources and a pair of low impedance or inefficient headphones.
Thx RossInDetroit. That's just what I needed to know about it.
@ross
Looking into my fairly average PC, I see a PSU that claims to have two 12V lines capable of supplying 16A and 18A, respectively.
Even subtracting what I already use, isn't that more or less exactly "a power supply capable of delivering 10-20V with a reasonable amount of current"?