Back when I was using personal tape players the volume amps were more
than adequate to drive a mid-market pair of headphones, like the
Sennheiser 457's. But now I'm using tapes less and less (arent we all)
and I find my MD portable
(Sony MD-MZN505) to be lacking in volume. If I crank the vol past 28
there starts to be distortion. I think the amps in most personal
portables are at only 5mw to save on battery power, but audio quality
suffers.
I have both the Koss EQ 30 AND 5.0. For those that never heard of them
they take 2 AAA batteries are are about half the size of a cassette
tape. The battery life is excellent (usally well over 50 hours).The
older model, the 30, has better controls but both seem to be kind of
noisy. It seems they pick up high frequency noise from TV stations,
power lines, and cell phones very easily.
Poor sheilding I guess. Anyway I'm wondering if the Radio Shack 3-way
volume booster (cat 33-1109) is any better than the Koss EQ's.
It would be nice to get a nice portable amp without hearing the loud
splatter from cell phones (which are just about everywhere now) and
the hash and beeps from power lines.
I dont think power lines are even supposed to emit high frequency
noise but they do. I dunno if its from utility equipment or not.

Try these folks for an answer to your question:

http://www4.head-fi.org/forums/index.php?s=

Best place for headphone amps is "Headroom Corp.", www.headphone.com .

They have a fabulous line of headphone stuff. Best on the internet.

They have two great little battery powered amps, the Airhead (about $100)
and the better sounding Total Airhead (about $200).

I love my Total Airhead, and also use their massive and superb "Maxed Out
Home" ($999).

"JohnCM" wrote in message
m...
Back when I was using personal tape players the volume amps were more
than adequate to drive a mid-market pair of headphones, like the
Sennheiser 457's. But now I'm using tapes less and less (arent we all)
and I find my MD portable
(Sony MD-MZN505) to be lacking in volume. If I crank the vol past 28
there starts to be distortion. I think the amps in most personal
portables are at only 5mw to save on battery power, but audio quality
suffers.
I have both the Koss EQ 30 AND 5.0. For those that never heard of them
they take 2 AAA batteries are are about half the size of a cassette
tape. The battery life is excellent (usally well over 50 hours).The
older model, the 30, has better controls but both seem to be kind of
noisy. It seems they pick up high frequency noise from TV stations,
power lines, and cell phones very easily.
Poor sheilding I guess. Anyway I'm wondering if the Radio Shack 3-way
volume booster (cat 33-1109) is any better than the Koss EQ's.
It would be nice to get a nice portable amp without hearing the loud
splatter from cell phones (which are just about everywhere now) and
the hash and beeps from power lines.
I dont think power lines are even supposed to emit high frequency
noise but they do. I dunno if its from utility equipment or not.