Ipod to stereo amplifer: getting volume

[Dominic-Luc Webb]

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume. Not sure if this is resistivity issue or maybe
the Ipod needs a pre-amp, but I am guessing there are people
here who immediately recognize this problem and know how this
is generally solved. If there exists a commercial pre-amp, for
instance that would be nice to hear about.

Thanks in advance!

Dominic

 

[Eeyore]

Dominic-Luc Webb wrote:

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume. Not sure if this is resistivity issue or maybe
the Ipod needs a pre-amp, but I am guessing there are people
here who immediately recognize this problem and know how this
is generally solved. If there exists a commercial pre-amp, for
instance that would be nice to hear about.

You may have a 'crippled' Ipod.

I think there's a French law intended to save the hearing of youngsters that
limits the output from the headphone socket to a couple of milliwatts.

A ridiculous law but that's the French for you. As a result some manufacturers
ensure that ALL their manufacturing destined for the European market is
similarly crippled.

If you can get a firmware upgrade for the world market model it may overcvome
this problem.

Graham

 

[John Fields]

On Thu, 29 Nov 2007 12:44:38 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

I think there's a French law intended to save the hearing of youngsters that
limits the output from the headphone socket to a couple of milliwatts.

A ridiculous law but that's the French for you.

---
Hmmm... and guess where these came from?:

1. It is illegal to die in the Houses of parliament .

2. It is an act of treason to place a postage stamp bearing the
British monarch upside-down .

3. In Liverpool, it is illegal for a woman to be topless except as a
clerk in a tropical fish store

4. Mince pies cannot be eaten on Christmas Day .

5. In Scotland, if someone knocks on your door and requires the use
of your toilet, you must let them enter .

6. A pregnant woman can legally relieve herself anywhere she wants,
including in a policeman's helmet .

7. The head of any dead whale found on the British coast
automatically becomes the property of the king, and the tail of the
queen .

8. It is illegal to avoid telling the tax man anything you
do not want him to know, but legal not to tell him information you
do not mind him knowing .

9. It is illegal to enter the Houses of parliament in a suit of
armour .



--
JF

 

[Dominic-Luc Webb]

On Thu, 29 Nov 2007, Eeyore wrote:

Dominic-Luc Webb wrote:

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume.

You may have a 'crippled' Ipod.

While the followup was quite amusing, and I enjoyed reading it, I
suspect this is not specifically "crippled" for European market
since it is purchased in USA from major vendor. Checking some
search engines, I see there are some things like "iTube" that
look like something intended specifically to deal with this. On
the other hand, those things are quite pricy and it is not clear
what characteristics I am after. Anyone know any sanely priced
solutions that have worked well?

Dominic

 

[John Fields]

On Thu, 29 Nov 2007 17:07:33 +0100, Dominic-Luc Webb
<dlwebb@canit.se> wrote:

On Thu, 29 Nov 2007, Eeyore wrote:

Dominic-Luc Webb wrote:

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume.

You may have a 'crippled' Ipod.

While the followup was quite amusing, and I enjoyed reading it, I
suspect this is not specifically "crippled" for European market
since it is purchased in USA from major vendor. Checking some
search engines, I see there are some things like "iTube" that
look like something intended specifically to deal with this. On
the other hand, those things are quite pricy and it is not clear
what characteristics I am after. Anyone know any sanely priced
solutions that have worked well?

---
Maybe you connected it to a high-level input on your stereo?

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Failing that, Why not build a little battery powered amp to go
between the Ipod output and the stereo amp?


--
JF

 

[Michael Black]

Dominic-Luc Webb (dlwebb@canit.se) writes:

While the followup was quite amusing, and I enjoyed reading it, I
suspect this is not specifically "crippled" for European market
since it is purchased in USA from major vendor. Checking some
search engines, I see there are some things like "iTube" that
look like something intended specifically to deal with this. On
the other hand, those things are quite pricy and it is not clear
what characteristics I am after. Anyone know any sanely priced
solutions that have worked well?

Is the issue that you can't get things "loud enough" or that you

have to turn up the volume control to get the same level of
loud out of the stereo?

The former is more serious than the latter. Having to turn up
the volume control on the stereo doesn't mean anything but that
the level on the iPod is lower than the rest, as long as you can
get the same "loudness" out of the stereo it will do no harm. It's
merely inconvenient.

"Line level" is usually pretty vague. Even with stereo components,
I often find I have to adjust volume for various bits of equipment,
a combination of differing line levels and maybe source material. That
classical music CD is likely going to sound "quieter" than that Led
Zeppelin LP (because classical music tends to have more dynamic range,
ie ratio of loudest to weakest passages, and an LP may be forced
to compress to some level to keep it within specs).

Merely having to adjust volume between sources is generally just
annoying.

But if you find that you have to turn up the volume all the way and
it's still not "loud enough" then yes, likely a simple preamp will
be needed. I don't know what sort of commercial products are available.
It's not going to need much gain, and would be simple to build if you
were already into building electronic projects.

Michael

 

[Jitt]

In article <Pine.LNX.4.44.0711291233180.14485-
100000@uno.canit.se>, dlwebb@canit.se says...

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume. Not sure if this is resistivity issue or maybe
the Ipod needs a pre-amp, but I am guessing there are people
here who immediately recognize this problem and know how this
is generally solved. If there exists a commercial pre-amp, for
instance that would be nice to hear about.

Thanks in advance!

Dominic


My kids had Creative mp3 players that would not produce

sufficient sound volume when connected to "aux" inputs
directly. I made an adapter cable that loaded each headphone
output with a 33 ohm resistor; this gave useable volume.
A later Samsung unit did not have the problem.

 

[Michael Black]

John Fields (jfields@austininstruments.com) writes:

On Thu, 29 Nov 2007 17:07:33 +0100, Dominic-Luc Webb
dlwebb@canit.se> wrote:

On Thu, 29 Nov 2007, Eeyore wrote:

Dominic-Luc Webb wrote:

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume.

You may have a 'crippled' Ipod.

While the followup was quite amusing, and I enjoyed reading it, I
suspect this is not specifically "crippled" for European market
since it is purchased in USA from major vendor. Checking some
search engines, I see there are some things like "iTube" that
look like something intended specifically to deal with this. On
the other hand, those things are quite pricy and it is not clear
what characteristics I am after. Anyone know any sanely priced
solutions that have worked well?

---
Maybe you connected it to a high-level input on your stereo?

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

That's not going to work. Even a "weak" iPod is going to have

significantly higher output than a phono cartridge, and I'm sure
it's within the realm of overloading that phone stage.

Plus, the phono input would have all kinds of equalization that
he won't want, since the iPod doesn't have the required pre-emphasis.

And given how many times people keep asking about how they can connect
their turntable to a stereo or sound card without a phono preamp,
chances are good that there is no phone input on whatever unit
he has.

Michael

 

[Don Bowey]

On 11/29/07 8:07 AM, in article
Pine.LNX.4.44.0711291702420.6768-100000@uno.canit.se, "Dominic-Luc Webb"
<dlwebb@canit.se> wrote:

On Thu, 29 Nov 2007, Eeyore wrote:

Dominic-Luc Webb wrote:

I have quite powerful higher end stereo amplifer that accepts
signals from most of the usual input sources. We tried connecting
an Ipod output to the stereo at a party to discover we could not
get much volume.

You may have a 'crippled' Ipod.

While the followup was quite amusing, and I enjoyed reading it, I
suspect this is not specifically "crippled" for European market
since it is purchased in USA from major vendor. Checking some
search engines, I see there are some things like "iTube" that
look like something intended specifically to deal with this. On
the other hand, those things are quite pricy and it is not clear
what characteristics I am after. Anyone know any sanely priced
solutions that have worked well?

Dominic

I have two iPods in the household (an Original and a new Nano), and both of
them drive the (Sony) amp to a house shuddering loudness with gain to spare.

You haven't mentioned the output volume setting of your iPod. Have you
turned it up?

 

[Eeyore]

John Fields wrote:

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

Graham

 

[Bob Masta]

On Thu, 29 Nov 2007 08:55:27 -0800, Jitt <tser827@yahoo.com> wrote:

My kids had Creative mp3 players that would not produce
sufficient sound volume when connected to "aux" inputs
directly. I made an adapter cable that loaded each headphone
output with a 33 ohm resistor; this gave useable volume.
A later Samsung unit did not have the problem.

OK, I just have to ask: How does loading with a 33 ohm resistor
*increase* the volume? Normally we would expect a load to only
*decrease* volume, since it becomes the bottom leg of a voltage
divider with the output impedance of the source the top leg.

Or is there some sort of automagical sensing in the output circuit,
that increases the level when it sees a low load impedance?
Seems possible, and maybe even logical, so the same connector
can serve as headphone and line out. But I haven't encountered
it before... it this common?

Best regards,


Bob Masta

DAQARTA v3.50
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, FREE Signal Generator
Science with your sound card!

 

[John Fields]

On Fri, 30 Nov 2007 02:38:20 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Fields wrote:

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

---
I see...

So if something is plugged into the phono inputs the tone controls
stop working?


--
JF

 

[Jitt]

In article <475009b0.1246905@news.sysmatrix.net>,
NoSpam@daqarta.com says...

On Thu, 29 Nov 2007 08:55:27 -0800, Jitt <tser827@yahoo.com> wrote:


My kids had Creative mp3 players that would not produce
sufficient sound volume when connected to "aux" inputs
directly. I made an adapter cable that loaded each headphone
output with a 33 ohm resistor; this gave useable volume.
A later Samsung unit did not have the problem.

OK, I just have to ask: How does loading with a 33 ohm resistor
*increase* the volume? Normally we would expect a load to only
*decrease* volume, since it becomes the bottom leg of a voltage
divider with the output impedance of the source the top leg.

Or is there some sort of automagical sensing in the output circuit,
that increases the level when it sees a low load impedance?
Seems possible, and maybe even logical, so the same connector
can serve as headphone and line out. But I haven't encountered
it before... it this common?

Best regards,


Bob Masta

DAQARTA v3.50
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, FREE Signal Generator
Science with your sound card!

I was thinking the current-oriented output was unable to

drive the relatively high impedance input; the 33 ohm load
allowed the output circuit to function, developing enough
signal voltage across the resistor to give useable volume.

 

[Eeyore]

John Fields wrote:

Eeyore wrote:
John Fields wrote:

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

---
I see...

So if something is plugged into the phono inputs the tone controls
stop working?

Is that the best stupid response you can offer ?

The tone controls will not even remotely provide a decent inverse match to the
RIAA characteristic.

Furthermore the input will likely be grossly overloaded (especially at low
frequencies) when driven from a headphone output of the type mentioned.

You really are one very stupid old fool.

Graham

 

[Dominic-Luc Webb]

---
Maybe you connected it to a high-level input on your stereo?

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Failing that, Why not build a little battery powered amp to go
between the Ipod output and the stereo amp?


--
JF

Hi John!

My stereo has RCA jacks mainly and I used a cable with a microphone
jack on the Ipod headphone and the other end had RCA connectors. I
am not immune to building a simple battery powered preamp if you
know a simple design?

Thanks for your input.

Dominic

 

[Michael Black]

Jitt (tser827@yahoo.com) writes:

In article <475009b0.1246905@news.sysmatrix.net>,
NoSpam@daqarta.com says...
On Thu, 29 Nov 2007 08:55:27 -0800, Jitt <tser827@yahoo.com> wrote:


My kids had Creative mp3 players that would not produce
sufficient sound volume when connected to "aux" inputs
directly. I made an adapter cable that loaded each headphone
output with a 33 ohm resistor; this gave useable volume.
A later Samsung unit did not have the problem.

OK, I just have to ask: How does loading with a 33 ohm resistor
*increase* the volume? Normally we would expect a load to only
*decrease* volume, since it becomes the bottom leg of a voltage
divider with the output impedance of the source the top leg.

Or is there some sort of automagical sensing in the output circuit,
that increases the level when it sees a low load impedance?
Seems possible, and maybe even logical, so the same connector
can serve as headphone and line out. But I haven't encountered
it before... it this common?

Best regards,


Bob Masta

DAQARTA v3.50
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, FREE Signal Generator
Science with your sound card!

I was thinking the current-oriented output was unable to
drive the relatively high impedance input; the 33 ohm load
allowed the output circuit to function, developing enough
signal voltage across the resistor to give useable volume.

That's a viable explanation, depending on the actual output
circuit. I haven't a clue what they use in those things, but
certainly if they had something that used the headphones to
to supply the current to the output stage, it certainly would
provide a terribly weak signal unless there was a suitably low
load there.

I thought, though, that they'd generally use something like
an op-amp, where there's current to the output device whether
or not there's a load. I do note that out of three portable
CD players, one portable cassette player and one MP3 player
that I have, none require a low impedance DC load to provide
suitable output level. Their outputs vary in level, and they
all seem to be lower level than my component CD player (though
my component DVD player seems to suffer from a lower output
level), but not a major difference in level.

Michael

 

[John Fields]

On Fri, 30 Nov 2007 17:14:02 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

John Fields wrote:

Eeyore wrote:
John Fields wrote:

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

---
I see...

So if something is plugged into the phono inputs the tone controls
stop working?

Is that the best stupid response you can offer ?

The tone controls will not even remotely provide a decent inverse match to the
RIAA characteristic.

Furthermore the input will likely be grossly overloaded (especially at low
frequencies) when driven from a headphone output of the type mentioned.

---
Geez, isn't there a volume control on an Ipod?


--
JF

 

[Jamie]

John Fields wrote:

On Fri, 30 Nov 2007 17:14:02 +0000, Eeyore
rabbitsfriendsandrelations@hotmail.com> wrote:



John Fields wrote:


Eeyore wrote:

John Fields wrote:


If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

---
I see...

So if something is plugged into the phono inputs the tone controls
stop working?

Is that the best stupid response you can offer ?

The tone controls will not even remotely provide a decent inverse match to the
RIAA characteristic.

Furthermore the input will likely be grossly overloaded (especially at low
frequencies) when driven from a headphone output of the type mentioned.


---
Geez, isn't there a volume control on an Ipod?


Most likely not on his, they would likely charge him

a luxury tax for that option.



--
"I'd rather have a bottle in front of me than a frontal lobotomy"
http://webpages.charter.net/jamie_5

 

[Eeyore]

John Fields wrote:

On Fri, 30 Nov 2007 17:14:02 +0000, Eeyore
rabbitsfriendsandrelations@hotmail.com> wrote:



John Fields wrote:

Eeyore wrote:
John Fields wrote:

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

---
I see...

So if something is plugged into the phono inputs the tone controls
stop working?

Is that the best stupid response you can offer ?

The tone controls will not even remotely provide a decent inverse match to the
RIAA characteristic.

Furthermore the input will likely be grossly overloaded (especially at low
frequencies) when driven from a headphone output of the type mentioned.

---
Geez, isn't there a volume control on an Ipod?

You even more ignorant piece of shit.

If you tuern down the volume control you'll still get significant output noise. The
volume control is not some passive attenuator acting directly at the output.

So the output noise will be amplified by the high gain phono input and the
signal-to-noise ratio will be atrocious.

You really shouldn't try to give advice about areas of technology you're completely
ignorant of. But of course you simply can't resist butting in and trying to look
'smart' can you, you utter fuckwit.

Graham

 

[Fleetie]

"John Fields" <jfields@austininstruments.com> wrote

On Fri, 30 Nov 2007 02:38:20 +0000, Eeyore
rabbitsfriendsandrelations@hotmail.com> wrote:
John Fields wrote:

If they still make stereos with phono inputs and yours has 'em, it
seems that should work.

Phono inputs have RIAA equalistaion on them you daft bugger. They would be
COMPLETELY unsuitable.

---
I see...

So if something is plugged into the phono inputs the tone controls
stop working?
JF

Well I'm not interested in getting involved in the ad hominem stuff
going on here, but on this occasion, Graham "Eeyore" is absolutely and
totally right.

There's no way that you could get acceptable sound by plugging a
nominally frequency-flat source (e.g. an iPod) into a phono input,
no matter how much the source was attenuated. The phono input has a
_severely_ tailored frequency response designed specifically and only
for turntable playback. Tone controls will only make the mess worse,
or at least, will go no way to sorting out the response.

The sound would be VERY bass-heavy, and there'd be almost no treble.
For a SMALL range of frequencies, somewhere in the middle of the frequency
band, the response would be flat. All of this assumes an ideal RIAA
response on the phono input.

You need to wiki "RIAA Equalisation".

The response used in phono inputs - being the opposite of that used
when driving the cutting head - has 2 main features:

1) It boosts bass, and lower frequencies are boosted more.
2) It attenuates treble, and higher frequencies are cut more.

The reasons are as follows:

1: To get decent bass playback without boosting bass on playback,
the groove excursions would be *enormous* and the stylus could and would
never, ever track. So you cut bass on recording and boost it back
on playback. That way, groove excursion is kept under control. Lower
frequencies need this treatment even more.

2: To mitigate surface noise, it is good to cut treble on playback,
so you boost it when cutting. That way, you maintain a good signal
from the original music, but severely attenuate high-frequency
surface noise. This is a good thing.

This is all "hi-fi 101".


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie