Hi,

I'm trying to find out if there is a way to connect the REC/Phones output of
my Roland Micro Cube amplifier to a Microphone input on a laptop. Assuming
the Mic-In is low impedance, is there a way to convert the high voltage
line signal of the amp to the microphone input? All I found so far is to do
the opposite: connecting a mic to a line input. Where can I buy such a
impedance matcher?

Also, I would like to know if it is ok to connect a 600 Ohm mic to a 10kOhm
mic input.

best,
Jeroen

"JW" wrote ...
I'm trying to find out if there is a way to connect the REC/Phones
output of my Roland Micro Cube amplifier to a Microphone input
on a laptop. Assuming the Mic-In is low impedance, is there a way
to convert the high voltage line signal of the amp to the microphone
input?

You need a simple attenuator to knock the line~level from your
amplifier down to mic-level for your laptop. Note that most
laptop mic inputs are mono. Hope you weren't expecting to
listen/record stereo. Impedance is really not the issue here.

All I found so far is to do the opposite: connecting a mic to
a line input.

That would be a mic preamp.

Where can I buy such a impedance matcher?

Last time I checked, you could buy a cable at Radio Shack
here in the US that had an attenuator built-in for connecting
line-level sources to mic-level inputs. Dunno if you have
an equivalent electronics mass-marketer in .nl? Likely
available someplace online also.

Or if you are a friend are handy with a soldering iron, it is
easily made with a couple of resistors that cost only a few
pennies. Information (more than you will ever need!) is
availble at www.epanorama.net

Also, I would like to know if it is ok to connect a 600 Ohm
mic to a 10kOhm mic input.

Yes. Impedance isn't really the issue here either.

On Sat, 23 Oct 2004 19:21:39 +0200, JW
wrote:

I'm trying to find out if there is a way to connect the REC/Phones output of
my Roland Micro Cube amplifier to a Microphone input on a laptop. Assuming
the Mic-In is low impedance, is there a way to convert the high voltage
line signal of the amp to the microphone input? All I found so far is to do
the opposite: connecting a mic to a line input. Where can I buy such a
impedance matcher?

Also, I would like to know if it is ok to connect a 600 Ohm mic to a 10kOhm
mic input.

A quick Google found this. Still true for non-specialist computer
sound systems I think.

The main points are that the mic input is mono. Ring doesn't expect
one of the stereo channels, it outputs a voltage. This is current
limited, you'll do no harm to computer or source by connecting to it.
But you won't get one channel of your music.

So you need a cable that connects both stereo outputs to tip of a
3.5mm jack plug.

You'll need to adjust the output level of your source way down. The
computer's software mixer almost certainly acts on the signal after it
has been digitised. It can't compensate for overload at the input.
And you have the potential for MASSIVE overload here. Nothing will
blow up, but it will sound terrible :-)

Your last hurdle is the utter crapness of mic inputs on consumer sound
cards. If there's a Line In, it can be pretty good. But, somehow,
mic in is usually mega-crappy.

Havind said that, make up a cable and try. You may be lucky :-)


.................................................. .................................................. ............
Soundblaster soundcard series (SB16, SB32, AWE32 and AWE64) have all a
microphone input designed to be used with the electret microphones
which come with the soundcard package (some packages) or with separate
microphone designed to be used with SoundBlaster soundcards (there are
separate microphones and some monitors have built-in microphones like
this).


Typical characteristics of Sound Blaster microphone input:
Input Type: Unbalanced Low Impedance
Input Sensitivity: Approx. -20dBV (100mV or 0.1Volt)
Input Impedance: 600 to 1500. (Ohms)
Input Connector: 3.5mm Miniplug (Stereo Jack)
Input Wiring: Audio on Tip, Ground on Sleeve, 5Volts DC Bias on
Ring

Because the microphone input needs very high input levels it is not
suitable to be used with any other micophone

"Laurence Payne" wrote in message
...
On Sat, 23 Oct 2004 19:21:39 +0200, JW
wrote:

I'm trying to find out if there is a way to connect the REC/Phones output
of
my Roland Micro Cube amplifier to a Microphone input on a laptop. Assuming
the Mic-In is low impedance, is there a way to convert the high voltage
line signal of the amp to the microphone input? All I found so far is to
do
the opposite: connecting a mic to a line input. Where can I buy such a
impedance matcher?

Also, I would like to know if it is ok to connect a 600 Ohm mic to a
10kOhm
mic input.

A quick Google found this. Still true for non-specialist computer
sound systems I think.

http://www.epanorama.net/links/pc_sound.html

On Sat, 23 Oct 2004 20:21:41 -0700, "Richard Crowley"
wrote:

http://www.epanorama.net/links/pc_sound.html

Which of the many links there do you recommend? I rather liked:

"a mic input jack (with a 1/8" stereo minijack). Here's what you
should do with this: nothing. It's not meant for music mics at all.
It's designed specifically for computer mics. The fact that it has 3
connections should give you a hint that there's something weird about
this jack. Pretend it's not there and don't plug a thing into it,
especially a microphone! One guy who wrote to me was tearing his hair
out in frustration because his recorded sound was so distorted; it
turned out he was recording through his computer mic that he forgot
was plugged in there..."
from:
http://www.homerecording.com/sound_card_basics.html

"Laurence Payne" wrote ...
On Sat, 23 Oct 2004 20:21:41 -0700, "Richard Crowley"
wrote:

http://www.epanorama.net/links/pc_sound.html

Which of the many links there do you recommend?

Hard to recommend a specific one as the original question was
somewhat incoherent.

I rather liked:

"a mic input jack (with a 1/8" stereo minijack). Here's what you
should do with this: nothing. It's not meant for music mics at all.

Sounds good to me.

Richard Crowley wrote:

"JW" wrote ...
I'm trying to find out if there is a way to connect the REC/Phones
output of my Roland Micro Cube amplifier to a Microphone input
on a laptop. Assuming the Mic-In is low impedance, is there a way
to convert the high voltage line signal of the amp to the microphone
input?

You need a simple attenuator to knock the line~level from your
amplifier down to mic-level for your laptop. Note that most
laptop mic inputs are mono. Hope you weren't expecting to
listen/record stereo. Impedance is really not the issue here.

Mono is ok.

All I found so far is to do the opposite: connecting a mic to
a line input.

That would be a mic preamp.

Yes, precisely the opposite from what I want.

Where can I buy such a impedance matcher?

Last time I checked, you could buy a cable at Radio Shack
here in the US that had an attenuator built-in for connecting
line-level sources to mic-level inputs. Dunno if you have
an equivalent electronics mass-marketer in .nl? Likely
available someplace online also.

Sure we do! The only problem is to find the right word/component to ask for.
I will ask for an attenuator, as you suggested.

thanks for your answer,
Jeroen

Laurence Payne wrote:

On Sat, 23 Oct 2004 19:21:39 +0200, JW
wrote:

I'm trying to find out if there is a way to connect the REC/Phones output
of my Roland Micro Cube amplifier to a Microphone input on a laptop.
Assuming the Mic-In is low impedance, is there a way to convert the high
voltage line signal of the amp to the microphone input? All I found so far
is to do the opposite: connecting a mic to a line input. Where can I buy
such a impedance matcher?

Also, I would like to know if it is ok to connect a 600 Ohm mic to a
10kOhm mic input.

A quick Google found this. Still true for non-specialist computer
sound systems I think.

I have found this answer myself too, this is not the problem. All my
connectors are mono anyway.

The main points are that the mic input is mono. Ring doesn't expect
one of the stereo channels, it outputs a voltage. This is current
limited, you'll do no harm to computer or source by connecting to it.
But you won't get one channel of your music.

So you need a cable that connects both stereo outputs to tip of a
3.5mm jack plug.

You'll need to adjust the output level of your source way down. The
computer's software mixer almost certainly acts on the signal after it
has been digitised. It can't compensate for overload at the input.
And you have the potential for MASSIVE overload here. Nothing will
blow up, but it will sound terrible :-)

This is the description of my problem/question, not an answer! ;-)

.................................................. .................................................. ...........
Soundblaster soundcard series (SB16, SB32, AWE32 and AWE64) have all a
microphone input designed to be used with the electret microphones
which come with the soundcard package (some packages) or with separate
microphone designed to be used with SoundBlaster soundcards (there are
separate microphones and some monitors have built-in microphones like
this).


Typical characteristics of Sound Blaster microphone input:
Input Type: Unbalanced Low Impedance
Input Sensitivity: Approx. -20dBV (100mV or 0.1Volt)
Input Impedance: 600 to 1500. (Ohms)
Input Connector: 3.5mm Miniplug (Stereo Jack)
Input Wiring: Audio on Tip, Ground on Sleeve, 5Volts DC Bias on
Ring

Now, this is useful info. I couldn't find info like this on the Creatives
website...

Because the microphone input needs very high input levels it is not
suitable to be used with any other micophone

best,
Jeroen

Laurence Payne wrote:

On Sat, 23 Oct 2004 20:21:41 -0700, "Richard Crowley"
wrote:

http://www.epanorama.net/links/pc_sound.html

Which of the many links there do you recommend? I rather liked:

"a mic input jack (with a 1/8" stereo minijack). Here's what you
should do with this: nothing. It's not meant for music mics at all.
It's designed specifically for computer mics. The fact that it has 3
connections should give you a hint that there's something weird about
this jack. Pretend it's not there and don't plug a thing into it,
especially a microphone! One guy who wrote to me was tearing his hair
out in frustration because his recorded sound was so distorted; it
turned out he was recording through his computer mic that he forgot
was plugged in there..."
from:
http://www.homerecording.com/sound_card_basics.html

Thanks for this link, it is pretty helpful.

Btw, I found another solution to my problem: an external soundcard. You can
buy USB soundcards with line and mic inputs. I'm not all too excited about
sending audio over a USB cable, since a steady throughput is not guaranteed
100%, but it is worth a try I guess. Especially since all I hear is: mic-in
is crappy on most computers.

best,
Jeroen

"JW" wrote in message
...
Hi,

I'm trying to find out if there is a way to connect the REC/Phones output
of
my Roland Micro Cube amplifier to a Microphone input on a laptop. Assuming
the Mic-In is low impedance, is there a way to convert the high voltage
line signal of the amp to the microphone input? All I found so far is to
do
the opposite: connecting a mic to a line input. Where can I buy such a
impedance matcher?

Also, I would like to know if it is ok to connect a 600 Ohm mic to a
10kOhm
mic input.

Does your laptop have a Mic Input but no Line Input ?!!!

geoff

"JW" wrote in message
Btw, I found another solution to my problem: an external soundcard. You
can
buy USB soundcards with line and mic inputs. I'm not all too excited about
sending audio over a USB cable, since a steady throughput is not
guaranteed
100%, but it is worth a try I guess. Especially since all I hear is:
mic-in
is crappy on most computers.

My M-Audio transit sucessfully sends or reeives 2 channels on USB1 at
24bit/96K, and does 2 channels both ways at 24bit/48K. Reliably, repeatably.

Of course don't count on that if you chain other USB devices, or plug things
in and out while recording. But the basic ability is quite solid.

geoff

On Tue, 26 Oct 2004 09:38:20 +0200, JW
wrote:

Btw, I found another solution to my problem: an external soundcard. You can
buy USB soundcards with line and mic inputs. I'm not all too excited about
sending audio over a USB cable, since a steady throughput is not guaranteed
100%, but it is worth a try I guess. Especially since all I hear is: mic-in
is crappy on most computers.

The good ones are Firewire. A few USB2 ones are appearing, but
mostly the market has gone to Firewire.


To do this job properly, you need a source with a proper Line Out, a
mixer to allow optimum level settings, and a soundcard with Line In.

Anything else will be a kludge. How important is quality to this
job?

"Geoff Wood" wrote ...
Does your laptop have a Mic Input but no Line Input ?!!!

Virtually all laptops have mic inputs.
A small minority of them have line inputs.

"JW" wrote ...
Richard Crowley wrote:
Last time I checked, you could buy a cable at Radio Shack
here in the US that had an attenuator built-in for connecting
line-level sources to mic-level inputs. Dunno if you have
an equivalent electronics mass-marketer in .nl? Likely
available someplace online also.

Sure we do! The only problem is to find the right word/component
to ask for. I will ask for an attenuator, as you suggested.

I hope the people in your shops are better than in ours. Likely not
1 in 10 of them would even know how to pronounce "attenuator"
much less know what it is.

See RadioShack # 42-2152 "6.5' Attenuating Dubbing Cord"
On our side of the pond, it pays to do your homework and
walk into the shop with a model number.

"Richard Crowley" wrote in message
...
"Geoff Wood" wrote ...
Does your laptop have a Mic Input but no Line Input ?!!!

Virtually all laptops have mic inputs.
A small minority of them have line inputs.


100% of the laptops that I have experience have a Line In. But that is only
one !

geoff

Laurence Payne wrote:

On Tue, 26 Oct 2004 09:38:20 +0200, JW
wrote:

Btw, I found another solution to my problem: an external soundcard. You
can buy USB soundcards with line and mic inputs. I'm not all too excited
about sending audio over a USB cable, since a steady throughput is not
guaranteed 100%, but it is worth a try I guess. Especially since all I
hear is: mic-in is crappy on most computers.

The good ones are Firewire. A few USB2 ones are appearing, but
mostly the market has gone to Firewire.


To do this job properly, you need a source with a proper Line Out, a
mixer to allow optimum level settings, and a soundcard with Line In.

Anything else will be a kludge. How important is quality to this
job?

It is just for personal use (and entertainment), so the quality should be as
good as I can afford ;-) Seriously, the lowest acceptable quality would be
44kHz sampling rate with 16 bit sound. I don't mind having to filter out
some noise afterwards, but I don't think noise will be a problem. Tt isn't
now on my Desktop with a low-end integrated sound-card, in practice having
a S/N ratio better than 20dB (which is good enough
).

best,
Jeroen

Geoff Wood wrote:


"JW" wrote in message
Btw, I found another solution to my problem: an external soundcard. You
can
buy USB soundcards with line and mic inputs. I'm not all too excited
about sending audio over a USB cable, since a steady throughput is not
guaranteed
100%, but it is worth a try I guess. Especially since all I hear is:
mic-in
is crappy on most computers.

My M-Audio transit sucessfully sends or reeives 2 channels on USB1 at
24bit/96K, and does 2 channels both ways at 24bit/48K. Reliably,
repeatably.

I've spotted this one too. However the "McGriffin IMic" is 50% cheaper,
because it doesn't offer the digital and optical inputs I don't need.

best,
Jeroen

"Jeroen" wrote in message


I've spotted this one too. However the "McGriffin IMic" is 50%
cheaper, because it doesn't offer the digital and optical inputs I
don't need.

The Griffen iMic is IME a highly asymmetrical device. The playback side
sounds (and measures) great for the price while the record side sounds (and
measures) pretty bad.