Audio/Mic inputs??

[picklemeister]

Hi
I use the X51v and I want to use it for audio recording & mixinig music.
I have a very good multi-track mixer prog called MeTeoR -
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This is a 16 channel multi-track recording app that is great for recording
on the road.
I've read on this site that the headphone socket actually has a mic input
& you just use the 4-connector 3.5mm jack to plug into it.

Question: Is this true? -
Can I make an input using a 4-connector pin & hardwire it to be a mono in?
Can I use it to plug in an electric guitar or bass (thru a Zoom-505 using line-out) to record tracks?

If so, why haven't there been any mention if this in the specs??
I've had my axim for about 2 years & was not aware of this !!!

[Gigi]

Welcome to the site!

Yes, it's true. However, you will need an adapter to be able to a 3.5mm mic into it. Seidio and other companies make these:

Dell Axim - >> Axim X50/X50V/X51/X51V

Here's a review:

http://www.aximsite.com/boards/vbart...audio-adapters

[picklemeister]

Thanks for responding --

I think the cable I want is no longer available - the one with the headphone jack & a separate mic in jack is not available at the site you've posted.

If anyone can tell me what the pinout configuration is for the axim I will male my own cable to use...
I need a 4-conductor 3.5mm jack, but which segment is which?
There is no set standard for that - is there??
I will assume that the center pin is the common, the next two are
Left & Right, & the sleeve closest to the rubber handle would be the mic in?

I dont want to open it up to find out - does anyone know for sure???

Thanks anyone for help.

[spunker88]

I googled for you and found the product you were looking for:
MICROPHONE/SPEAKER AUDIO ADAPTOR - ADA-IP6335MY35F

If your up to it and have the supplies, there is also a tutorial on how to build one.
Axim: in-out audio cable (English) - Mobile Technology

[picklemeister]

:approve:

That is a very good tutorial man, Thanks a lot!

I have one problem tho & that is that I cannot find a 4-pin connector to use
except for ones from A/V cables for Vidcams or for Ipods - & they cost acout $20 around my town.... So I will just buy the one you sent the link for!
Radio Shack & Circuit City had No 4-pin connectors available or I would definately make one of these

New question has arisen from the tutorial tho ...
It mentions at the begining that you CANNOT use the mic in & the stereo out simultaneously
I will need it to do so. No point whatsoever in getting anything if I cant hear what I'm adding a line to ..... ??
Is this what actually happens or am I getting more lost?

I would be playing a file in the Axim, listening over headphones, playing some instrument that is plugged into the mic, & recording just the mic in as a different file so that the Meteor program can later load all the separately recorded files (called a session) & play them all back, synced in time to my specifications - which can be manipulated.
If I cannot record while playing the other tracks, or if I cannot hear the other tracks while recording one, this will all have been wasted time & money!!

Can anyone give me more facts???

Input greatly appreciated :)

Pickle-out

[Bill_Todd]

stereoout/mic in - there is a standard. it evolved from
mono jacks (sleeve ground, tip live)
stereo (sleeve ground, tip left, ring right)
leaving the new second ring for mic/line input (the input is usefully grounded by the sleeve if mono or stereo jacks are used).

meteor - nice little app :)

I'll pop the axim on to the bench and test the input for levels etc. and report back...

[Bill_Todd]

OK after a quick test I can confirm the stereo outs DO work while recording the mic input, i.e. you can hear the playback while laying down a new track. However, you cannot hear the track you're laying down (presumably to stop feedback while track laying).

I found the mic input switching to be a little tricky on my axim; I made a simple RCA phono to 4pole jack adapter for the test and found that I had to plug the adapter into the Axim before connecting the input to the phono, in order to get the Axim to switch to external mic input. I suspect the Axim senses the load on the mic power supply as the jack is inserted (the mic output sits at ~+3vdc in order to power electret mics capsules).


One thing you will need to do is add a considerable pad (attenuator) to the input; I measured a maximum input of just 20mVrms @ 1kHz ( ~-32dBV) on the input before it clipped.

[edit]
Inserting a 100n capacitor in line with the mic input fixed the switching problem.

Maximum output level appears to be around 220mVrms @1kHz so you might need an amplifier to lift the level into most monitoring equipement (see Aximiser thread for a suitable circuit)

[edit] correcting typo.

[Zaniax]

Nice work, Bill_Todd :approve:

... especially from a person born in 1905 :p

[psionandy]

Just out of interest.. what sort of sound quality do you get using the axim as a recording device?

[picklemeister]

Thank you guys for your help & interest !
I have been using the built in mic so far to record singing/accoustic guitar
or harmonicas or duets ... with a line in I will be able to add 2nd 3rd & so on lines to the first without altering the original line(s) - sound quality has been very good just by pressing record & set it on the table about 2 or three feet from the person - concerts I've been to tend to completely overpower the thing - I havent found a way to turn down the recording level so I just move it closer or further away from the source to control the input level. There is a control however in the settings/system/microphone page to use auto gain control or manually turn it up/down - but I cannot see the results & have to go record something & then play it back to see if its ok - then maybe try again.

A concert like Jethro Tull - who normally will have an excellent sound in an auditorium will record quite well if you are near the back of the auditorium.
Most concerts will forget about mix quality & instead go for more volume on everything - which will give you a crappy recording no matter how you do it.

I use Meteor to record people I am trying to work with to get a useable copy of their stuff so I can go home & transfer the file to the desktop & continue with something like Cooledit pro (now owned by Adobe & called Audition).
Cooledit can remove noise & hiss & clean up everything & allow me to add another hundred & twentyfive tracks to something & convert it all to MP3 or whater. Meteor can also convert the project to an mp3 if I want it to, but it is a bit slow at that in the Axim - but I have done it many times.
Any way - sound quality is good enough but you will want to know how to edit soundfiles & clean up things to make it more professional. Meteor can do tons of editing right on the PDA -& add some effects too - like reverb & delay & distortion & whatnot.

Bottom Line:
Axim X51v + Meteor + Autotuner + RTA-Pro = Indespensible toy!

If I can now use the mic input, I will likely also be able to get another music app called Stompbox, which is an electric guitar effects program that can probably be used with Meteor (I hope) to make my axim become totally Rad.
I wish I knew about the mic input last year!

Pickle out

[picklemeister]

BTW:

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[Bill_Todd]

Pickle, (continuing from other thread)

I've just found this: mic transformer adapter from a UK based supplier.

It has a very useful 10:1/1:1 transformer that would be idle as the core part in a mic/line input for the Axim.

Can you find anything similar in Canada at your local suppliers?

[Bill_Todd]

I've just measured a couple of cheap Eagle International transformers (these used to be available everywhere for intermediate and output stages in transistor amps)

Model LT.44 (transistor driver transformer) 20kOhms primary - 1kohms centre tapped secondary. This would make a useful Axim output transformer; using the secondary (1k) winding as the input from the Axim, and the primary(20k)as output give 14dB of voltage gain (i.e. -10dBV out the axim gives about +4dBV into a high impedance at the output)

Model LT.700 is a output transformer (1k CT primary: 8R secondary) I found somthing similar for sale on ebay here.

By using the tranformer in reverse (i.e. mic into the 8R secondary and axim mic connected to the primary) this would give you about +24dB of voltage gain, although you would need to test this with the mic as you are abusing the transformer using it in this way.

[picklemeister]

Pickle, (continuing from other thread)

I've just found this: mic transformer adapter from a UK based supplier.

It has a very useful 10:1/1:1 transformer that would be idle as the core part in a mic/line input for the Axim.

Can you find anything similar in Canada at your local suppliers?

Hi Bill
Yes - this adapter is a standard connector in recording music.
It's main purpose is to convert the 3-pin balanced cable of a mic cable to a 2-pin unbalanced signal to plug into mixing boards or other equipment.
Most equipment these days just has a plug to receive the 3-pin mic cables, & so wouldn't need this. I have 2 of 'em & yes - they will be used to plug any mic into the axims input...
A 3-pin mic gives out a BALANCED signal:
one of the pins is the normal signal
One of the pins is the ground
3rd pin is the signal again, but INVERTED. It is a mirror image of the normal signal. (180' inverted)
the balanced & normal & ground lines are carried through a standard mic cable from one end to other, straight through to where it is plugged in to.
On the receiving device, (including the one you've found) the inverted signal is flipped again, (Re-inverted) to be the same as the normal signal. Now, as a the signal travels along a long mic cable, it will just "pick up" noises -ie interference, static, humm & whatever. Both the normal & inverted signals as they travel through the cable will pick up the same noise as they run alongside each other.
When you re-invert the inverted signal, now the mic's original signal is the same again, but all the noise on both lines are now inverted to each other.
When these two signals are combined back together, they will either add together to be a stronger signal -the stuff you WANT, as it is now in phase, or they will CANCEL each other out - the noise -since it is now equal & opposite phase -
The Result: nice clean mic signal that has travelled a long way along a mic cable to a mixing board or some other equipment. (Usually NEEDED if the cable is 50ft or more)
This adapter you've found is for doing exactly that. It inverts one side, puts the two signals back together & cancels any noise & gives me a mono connector from a 3-pin cable so I can plug it in to something EXACLY like the Axim's mic in, provided the levels are compatible. I just need to add an adapter to shring the pin size to 3.5mm .
I dont really know if the Axim can handle this kind of signal since a simple headset mic is what its made for...a real mic signal may be much higher than that kind if thing.
I'm interested in also using a Guitar signal which is different again.
I should make a connector that is switchable from Hi-Z to Lo-Z (impedance)
to do both of those things.....
I'm looking into the Transformer you've found

Thank you very much !!
P

[picklemeister]

Pickle, (continuing from other thread)

I've just found this: mic transformer adapter from a UK based supplier.

It has a very useful 10:1/1:1 transformer that would be idle as the core part in a mic/line input for the Axim.

Can you find anything similar in Canada at your local suppliers?

Oh yeah -
BTW- the adapter you've found also has a switch -
it is for switching between Hi-Z or Lo-Z (impedance) - I think a guitar output is Hi-Z, and a normal quality mic (like a Shure SM-57 or SM-58) is Lo-Z
(or vice-versa - I forget which is which now)

P