[Greg Grainger]

Apologies if this has been asked before.

I want to plug my mp3 player into my preamp, but the player has only the
headphone output. I have the right cables, but the sound is all tinny and
odd. Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

Any thoughts? suggestions? I have not yet been to 'The Source' or anywhere
else - I want to know what I'm talking about before I get there.

Many thanks in advance,
Greg.
--
Greg Grainger grainger(at)vex.net

'What a world of gammon and spinach it is, though, ain't it?'
- Miss Mowcher

[[email protected]]

On Apr 6, 3:24*pm, (Greg Grainger) wrote:
Apologies if this has been asked before.

I want to plug my mp3 player into my preamp, but the player has only the
headphone output. I have the right cables, but the sound is all tinny and
odd. Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

Any thoughts? suggestions? I have not yet been to 'The Source' or anywhere
else - I want to know what I'm talking about before I get there.

Many thanks in advance,
Greg.

That sounds really strange. The MP3 player should drive any line input
without any problems. The headphone output has a relatively low
impedance meaning that it will be quite happy driving this type of
input. Have you tried any other inputs on your preamp or other
amplifier?

[Arny Krueger]

"Greg Grainger" wrote in message


Apologies if this has been asked before.

I want to plug my mp3 player into my preamp, but the
player has only the headphone output. I have the right
cables, but the sound is all tinny and odd.

Totally unexpected.

Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

The mp3 player already has the right signal and impedances for your preamp.

Zillions of people are doing what you're struggling with. There has to be
something else wrong, perahps with the preamp input. Anything that drives
headphones can drive a regular hi-fi line level input.

[René[_2_]]

On 6 Apr 2009 19:24:37 GMT, (Greg Grainger) wrote:

Apologies if this has been asked before.

I want to plug my mp3 player into my preamp, but the player has only the
headphone output. I have the right cables, but the sound is all tinny and
odd. Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

Any thoughts? suggestions? I have not yet been to 'The Source' or anywhere
else - I want to know what I'm talking about before I get there.

Many thanks in advance,
Greg.

Push the plug in all the way. If not you will only hear the difference
between the channels - tinny and odd.

I once had to actually trim the plug to make it go in far enough.

Either that or the ground connection in the plug became dislodged.


--
- Blarp the Enigmatic

[[email protected]]

On Apr 6, 3:24*pm, (Greg Grainger) wrote:
Apologies if this has been asked before.

I want to plug my mp3 player into my preamp, but the player has only the
headphone output. I have the right cables, but the sound is all tinny and
odd. Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

Any thoughts? suggestions? I have not yet been to 'The Source' or anywhere
else - I want to know what I'm talking about before I get there.

If you come straight out of the headphone jack, you will very often
get distorted sound due to the op-amp headphone driver of the MP3
player - this depends on the brand/type of MP3 player to a degree, but
is generally true for non-Apple units. What you want is a docking
station cable with RCA outputs. they are a bit pricier than miniature
phono-to-RCA cable that you are using - but you will get a true line-
level output this way - something more compatible with your pre-amp.

If your player is not compatible with a docking station cable, you may
have to go to the extreme of getting a compatible FM unit (wireless
output for a car stereo) for it and transmit to your tuner. Keep in
mind that many inexpensive MP3 players are designed to live on your
body and feed earbuds - not to be an audio component and part of your
stereo.

Peter Wieck
Melrose Park, PA

[[email protected]]

On Apr 7, 10:43*am, " wrote:
snip

If you come straight out of the headphone jack, you will very often
get distorted sound due to the op-amp headphone driver of the MP3
player - this depends on the brand/type of MP3 player to a degree, but
is generally true for non-Apple units. What you want is a docking
station cable with RCA outputs. they are a bit pricier than miniature
phono-to-RCA cable that you are using - but you will get a true line-
level output this way - something more compatible with your pre-amp.

It is not clear why there should be any significant distortion in this
case. I have used a variety of portable electronics to drive a line
input without any significant problems. It is possible that you are
overdriving the preamp input. If that is the case, just reduce the
player volume.

If your player is not compatible with a docking station cable, you may
have to go to the extreme of getting a compatible FM unit (wireless
output for a car stereo) for it and transmit to your tuner.

This may cause more problems than it solves. The sound quality with FM
transmitters may not be very good.

Keep in
mind that many inexpensive MP3 players are designed to live on your
body and feed earbuds - not to be an audio component and part of your
stereo.

Even so, the signal from such players should not sound any worse when
amplified by a competent amplifier setup.

[[email protected]]

On Apr 7, 2:38*pm, wrote:

It is not clear why there should be any significant distortion in this
case. I have used a variety of portable electronics to drive a line
input without any significant problems. It is possible that you are
overdriving the preamp input. If that is the case, just reduce the
player volume.

With many cheap MP3 players, there is no 'lower volume' than the
initial volume - only louder. That is a function of the very cheap op-
amp outputs, and why this problem is quite common.

If your player is not compatible with a docking station cable, you may
have to go to the extreme of getting a compatible FM unit (wireless
output for a car stereo) for it and transmit to your tuner.

This may cause more problems than it solves. The sound quality with FM
transmitters may not be very good.

As it happens, some of the after-market 'wireless' car systems are
very good for the purpose and when within a few feet of the tuner/
receiver. Some are no better than they have to be - but _ALL_ of them
require the correct input. Hence my statement of 'compatible' - not
just any one - although some have the means to attenuate the input
somewhat. As an aside to all this, my whole-house FM transmitter has
this capacity - not everyone, of course.

Keep in
mind that many inexpensive MP3 players are designed to live on your
body and feed earbuds - not to be an audio component and part of your
stereo.

Even so, the signal from such players should not sound any worse when
amplified by a competent amplifier setup.

Unless they are putting out too much noise or overloading the pre-amp
as noted above. There are attenuating patch-cords out there, but they
are very hard to find. They came about back in the day of the very
first "Walkman" type CD players when such users wanted to drive their
home stereos with this new technolgy. Very quickly even the cheap CD
portables got line-level outputs so the need all but dried up. I have
not seen them on the retail hoof for perhaps 20 years. I do keep two
such cables (miniature phono-to-RCA) but then, I have considerable
dinosaur-vintage equipment. The OP might try a pair of 50 - 100-ohm,
1/8 watt resistors (one in series with each 'hot') if he is so-
inclined, but that is a lot of work and shielding becomes an issue.
Again, back in the day, I have buried such inside the RCA connector
when I was making my own patch-cords. They fit nicely with a little
care.

Peter Wieck
Melrose Park, PA

[Arny Krueger]

"René" wrote in message
...

On 6 Apr 2009 19:24:37 GMT, (Greg Grainger) wrote:

I want to plug my mp3 player into my preamp, but the player has only the
headphone output. I have the right cables, but the sound is all tinny and
odd. Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

Any thoughts? suggestions? I have not yet been to 'The Source' or anywhere
else - I want to know what I'm talking about before I get there.

Push the plug in all the way. If not you will only hear the difference
between the channels - tinny and odd.

I once had to actually trim the plug to make it go in far enough.

Either that or the ground connection in the plug became dislodged.

I've had this experience more than once, but I quickly applied the solutions
you've mentioned and all was well.

It is possible that the particular adaptor he chose was either defective or
simply fit a little different than the headphones.

[[email protected]]

On Apr 7, 3:59*pm, " wrote:

With many cheap MP3 players, there is no 'lower volume' than the
initial volume - only louder. That is a function of the very cheap op-
amp outputs, and why this problem is quite common.

This is a remarkable observation. It is true that some inexpensive
electronics may be difficult to mute completely but it is hard to
imagine that the minimum level would cause distortion for a line
input. Line-level input for consumer gear is specified at .316Vrms so
any standard amplifier should be able to handle that. If the same
signal is applied to 32 ohm headphones, the resulting power is (.
316^2)/32 or a bit over 3 mw. Given that headphones typically have
sensitivity (measured at 1mw) of 90-100dB, this would result in a
sound level almost 5 dB higher which is really pretty loud. Why would
anyone buy an MP3 player with a minimum level of 105 dB? Actually, it
is quite easy to adjust volume level digitally over a wide range
anyway.


snip

As it happens, some of the after-market 'wireless' car systems are
very good for the purpose and when within a few feet of the tuner/
receiver. Some are no better than they have to be - but _ALL_ of them
require the correct input. Hence my statement of 'compatible' - not
just any one - although some have the means to attenuate the input
somewhat. As an aside to all this, my whole-house FM transmitter has
this capacity - not everyone, of course.

Agreed. Some transmitters sound good and some don't but level should
not be the problem.

snip

Unless they are putting out too much noise or overloading the pre-amp
as noted above.

The problem that the OP described does not sound at all like overload.
The plug problem described by Rene is a much more likely culprit.

snip

[Jenn[_2_]]

In article ,
"Arny Krueger" wrote:

"René" wrote in message
...

On 6 Apr 2009 19:24:37 GMT, (Greg Grainger) wrote:

I want to plug my mp3 player into my preamp, but the player has only the
headphone output. I have the right cables, but the sound is all tinny and
odd. Obviously I need some kind of tranformer to get the right
voltage/impedence for the AUX inputs on my preamp.

Any thoughts? suggestions? I have not yet been to 'The Source' or anywhere
else - I want to know what I'm talking about before I get there.

Push the plug in all the way. If not you will only hear the difference
between the channels - tinny and odd.

I once had to actually trim the plug to make it go in far enough.

Either that or the ground connection in the plug became dislodged.

I've had this experience more than once, but I quickly applied the solutions
you've mentioned and all was well.

It is possible that the particular adaptor he chose was either defective or
simply fit a little different than the headphones.

Greg, is the player an older iPod? There is a well-known issue with the
size of the plug with some patch cords and headphones.

[Greg Grainger]

In article ,
Jenn wrote:

Greg, is the player an older iPod? There is a well-known issue with the
size of the plug with some patch cords and headphones.

It was a cheap Samsung MP3 player. I have since lost it.

The new MP3 player (a more expensive Samsung) doesn't have this problem.

A co-worker (mixer and audio engineer) suggested that the solution would
be to bring the output volume on the player down, thus bringing the output
voltage as close to line level charactaristics as possible. It would then
be neccessary to set the volume control on the stereo higher to
compensate.

So far, all is good. No adaptor neccessary.

Thanks,
Greg.

--
Greg Grainger grainger(at)vex.net

'What a world of gammon and spinach it is, though, ain't it?'
- Miss Mowcher