I haven't experimented too much with this, I just needed something as small as possible based around a Class AB headphone amplifier IC I found in an old TV that would pretty much compensate for the crappy volume limit that Apple have implemented on their iPods (as mentioned in the Apple Rant blog earlier)
and I'm sorry Chu Moy - your op-amp based buffer type headphone amp just doesn't cut the mustard for me.
the datasheet for this IC claims a THD of 0.001% so if that's your thing - power to you.
and a S/N ratio of 110dB
however the thing that interested me the most is that it's pretty low on current usage which maxes at about 7mA under load and around 3-5mA quiescent. I desoldered a 3v lithium battery holder from an old PC motherboard and used a lithium battery as the power source. but I'm sure 2 AA's or AAA's will work fine.
originally I was going to power it via a 9v/5v regulator method but I thought it would be a pain in the arse when carrying it around in my pocket.
I may do some scope captures at some point but until then - this thing works great.
Since everyone feels the need to disclaim liabilities I shall do the same. If you build this and listen to music too loud and you damage your hearing, it's your own fault.
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| Testing to see if it works - it does! |
Really neat, compact build. Will be great if you can get the required juice out of the little 'hearing aid' battery. Still as is I like it, Makes my iPod's output range alot more useful instead of that ultra conservative cap they dumped on it because of a few idiots and the supplied apple ear raping buds, With a good pair of open backed cans (My case the AKG K-702 model)it does them alot more justice. Nice one Paul
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