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Gear / Technical Help => Recording Gear => Topic started by: lordbelial on May 23, 2006, 03:02:39 AM

Title: I-River input impedance?
Post by: lordbelial on May 23, 2006, 03:02:39 AM

Hi,

I was wondering which was the input impedance for the line input of the Iriver.

Does anybody know?

Thanks,

Title: Re: I-River input impedance?
Post by: udovdh on May 23, 2006, 03:35:29 AM

Quote from: lordbelial on May 23, 2006, 03:02:39 AM

Hi,

I was wondering which was the input impedance for the line input of the Iriver.

Does anybody know?

Same here. Could not find any info.

Title: Re: I-River input impedance?
Post by: lordbelial on May 23, 2006, 05:13:33 AM

Quote from: udovdh on May 23, 2006, 03:35:29 AM

Quote from: lordbelial on May 23, 2006, 03:02:39 AM

Hi,

I was wondering which was the input impedance for the line input of the Iriver.

Does anybody know?

Same here. Could not find any info.

Nice to see I'm not the one who's wondering... Let's wait to the most experienced Iriver users.

May it be a good idea to ask this on the rockbox forums?

Title: Re: I-River input impedance?
Post by: udovdh on May 23, 2006, 06:40:18 AM

I asked one or two questions at misticriver. No reply.

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 09:14:40 AM

10k

Quote from: lordbelial on May 23, 2006, 03:02:39 AM

Hi,

I was wondering which was the input impedance for the line input of the Iriver.

Does anybody know?

Thanks,

Title: Re: I-River input impedance?
Post by: udovdh on May 23, 2006, 10:18:37 AM

Quote from: Church-Audio on May 23, 2006, 09:14:40 AM

10k

Thanks!
Measured?
Or from specs some where?


BTW: Any idea on max input level with just analog attenuation?

Title: Re: I-River input impedance?
Post by: lordbelial on May 23, 2006, 11:55:23 AM

Quote from: Church-Audio on May 23, 2006, 09:14:40 AM

10k

Quote from: lordbelial on May 23, 2006, 03:02:39 AM

Hi,

I was wondering which was the input impedance for the line input of the Iriver.

Does anybody know?

Thanks,

Thanks! I never thought that It could have the same impedance as a mic-in from a Sharp MD....

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

Quote from: udovdh on May 23, 2006, 10:18:37 AM

Quote from: Church-Audio on May 23, 2006, 09:14:40 AM

10k

Thanks!
Measured?
Or from specs some where?


BTW: Any idea on max input level with just analog attenuation?

Title: Re: I-River input impedance?
Post by: udovdh on May 23, 2006, 12:34:10 PM

Quote from: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

OK, good! twice that of the MT.
Now the max analog input level with just analog attenuation?

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 01:53:01 PM

I do not understand your question sorry max input with analog attenuation? There is not such thing as analog attenuation in a digital circuit. Or are you talking externally if so the max input could be 100volts if you attenuate the signal enough :)
I will say that most recorders that have unbalanced inputs are 10k or pretty close too it.

Chris Church

Quote from: udovdh on May 23, 2006, 12:34:10 PM

Quote from: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

OK, good! twice that of the MT.
Now the max analog input level with just analog attenuation?

Title: Re: I-River input impedance?
Post by: udovdh on May 23, 2006, 02:05:23 PM

Quote from: Church-Audio on May 23, 2006, 01:53:01 PM

I do not understand your question sorry max input with analog attenuation? There is not such thing as analog attenuation in a digital circuit. Or are you talking externally if so the max input could be 100volts if you attenuate the signal enough :)
I will say that most recorders that have unbalanced inputs are 10k or pretty close too it.

The deck has some level controls that work in teh analog domain.
What is the max analog signal for 0dBFS I can feed into the deck with just the help of the analog level controls?

Title: Re: I-River input impedance?
Post by: graemecogger on May 23, 2006, 03:13:02 PM

Quote from: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

That's kind of weird  ???
My H120 is about 2.2K, not 10K - mostly influenced by a 2K7 resistor to the positive supply.  Maybe they changed the spec at some point?

Title: Re: I-River input impedance?
Post by: George on May 23, 2006, 03:31:32 PM

This is all I could find on iriver's site:

http://www.iriver.com/html/product/prpa_product.asp?pidx=43

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 05:09:21 PM

How did you measure it with an ohm meter or a impedance meter? they are very different measurements.

Chris Church

Quote from: graemecogger on May 23, 2006, 03:13:02 PM

Quote from: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

That's kind of weird  ???
My H120 is about 2.2K, not 10K - mostly influenced by a 2K7 resistor to the positive supply.  Maybe they changed the spec at some point?

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 05:10:43 PM

Your telling me this thing has a volume control that is not digital where do you look at the volume level on a display? or is it printed on the case?

Chris Church

Quote from: udovdh on May 23, 2006, 02:05:23 PM

Quote from: Church-Audio on May 23, 2006, 01:53:01 PM

I do not understand your question sorry max input with analog attenuation? There is not such thing as analog attenuation in a digital circuit. Or are you talking externally if so the max input could be 100volts if you attenuate the signal enough :)
I will say that most recorders that have unbalanced inputs are 10k or pretty close too it.

The deck has some level controls that work in teh analog domain.
What is the max analog signal for 0dBFS I can feed into the deck with just the help of the analog level controls?

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 05:13:28 PM

I just checked all controls are digital encoders so its all digital no analog.

Quote from: udovdh on May 23, 2006, 02:05:23 PM

Quote from: Church-Audio on May 23, 2006, 01:53:01 PM

I do not understand your question sorry max input with analog attenuation? There is not such thing as analog attenuation in a digital circuit. Or are you talking externally if so the max input could be 100volts if you attenuate the signal enough :)
I will say that most recorders that have unbalanced inputs are 10k or pretty close too it.

The deck has some level controls that work in teh analog domain.
What is the max analog signal for 0dBFS I can feed into the deck with just the help of the analog level controls?

Title: Re: I-River input impedance?
Post by: graemecogger on May 23, 2006, 07:25:33 PM

Quote from: Church-Audio on May 23, 2006, 05:09:21 PM

How did you measure it with an ohm meter or a impedance meter? they are very different measurements.

Chris Church

Quote from: graemecogger on May 23, 2006, 03:13:02 PM

Quote from: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

That's kind of weird  ???
My H120 is about 2.2K, not 10K - mostly influenced by a 2K7 resistor to the positive supply.  Maybe they changed the spec at some point?

Effectively a home-made impedance meter :)  1kHz signal into the input via a variable resistance - gave me about 2K2.  I also checked the DC resistance to the supply (current when shorted to GND, voltage when open circuit etc.), which was about 3.7K  From the circuit posted by the Rockbox developers, that's almost certainly 1K from V+ to an electrolytic (to GND), then 2K7 to the output.

Title: Re: I-River input impedance?
Post by: Church-Audio on May 23, 2006, 07:41:52 PM

Thats not what I got when I measured it with my hp impedance meter. Not that it really matters


Chris Chruch

Quote from: graemecogger on May 23, 2006, 07:25:33 PM

Quote from: Church-Audio on May 23, 2006, 05:09:21 PM

How did you measure it with an ohm meter or a impedance meter? they are very different measurements.

Chris Church

Quote from: graemecogger on May 23, 2006, 03:13:02 PM

Quote from: Church-Audio on May 23, 2006, 12:30:10 PM

I know it is because I have measured it with an impedance meter its aprox 10k

That's kind of weird  ???
My H120 is about 2.2K, not 10K - mostly influenced by a 2K7 resistor to the positive supply.  Maybe they changed the spec at some point?

Effectively a home-made impedance meter :)  1kHz signal into the input via a variable resistance - gave me about 2K2.  I also checked the DC resistance to the supply (current when shorted to GND, voltage when open circuit etc.), which was about 3.7K  From the circuit posted by the Rockbox developers, that's almost certainly 1K from V+ to an electrolytic (to GND), then 2K7 to the output.

Title: Re: I-River input impedance?
Post by: udovdh on May 24, 2006, 04:08:39 AM

We are talking line in here?
Hmm.
this is not good if it is really taht low.
Even lower than the MT!  ???