Taperssection.com
Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: MadMaster on August 04, 2006, 04:25:59 AM
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I recently bought an iRiver H120 and RockBoxed it.
I tested the H120 with my mic's and batterybox (MM-MCSM-4 cardioids -> MM-EBM-1 -> Iriver H120) but had almost no levels at 0dB gain at the H120 while the source of the sound was really loud. Only when I cranked up the gain at the iRiver to about +20dB I came close to the maximum peak.
I also recently bought a headphone amplifier Pocket Amp 2 - Version 2 (PA2V2) from the guy at http://www.electric-avenues.com. See the picture below.
Just for a test I connected it in between my batterybox and the H120 (gain level 0dB) and opened the gain complete at the PA2V2.
The rig at that time was MM-MCSM-4 cardioids -> MM-EBM-1 -> PA2V2 -> Iriver H120.
It gave about the same peaklevels as the situation without the PA2V2 and the overall sound of the recording was also about the same.
I only do stealth recordings and it would be nice if I could safely use this small amplifier in my rig.
Does anybody know if this is a save and reliable way to add gain to the iRiver H120?
(http://www.electric-avenues.com/ebay/features_pa2.jpg)
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Nobody??? :-[
I hoped that somebody could/would analyse the specs of the amplifier (I'm a noob on electric components) and would like to give his/her 2 cents...
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The question is impossible to answer first of all, the preamp your thinking of using is meant to take a high level input source. Like the output of a cd player and boost it to low imp output. This is not what your doing your connecting a low level signal to a hi imp input. I would think that you might introduce noise as high level or line level devices do not have shielding (because the signal is so much louder then the noise floor) The only way to know if it will work is to simply use it and see what happens I would listen for noise and see if this introduces more noise into your recording. I have talked to the guy that builds these headphone amps and he does a great job, but they are headphone amps not a mic preamp. So that’s my 2 cents on this subject. I would find out what the input impedance is and output impedance is 10k in and 10k out is good for an unbalanced electret mic preamp.
Chris Church
I recently bought an iRiver H120 and RockBoxed it.
I tested the H120 with my mic's and batterybox (MM-MCSM-4 cardioids -> MM-EBM-1 -> Iriver H120) but had almost no levels at 0dB gain at the H120 while the source of the sound was really loud. Only when I cranked up the gain at the iRiver to about +20dB I came close to the maximum peak.
I also recently bought a headphone amplifier Pocket Amp 2 - Version 2 (PA2V2) from the guy at http://www.electric-avenues.com. See the picture below.
Just for a test I connected it in between my batterybox and the H120 (gain level 0dB) and opened the gain complete at the PA2V2.
The rig at that time was MM-MCSM-4 cardioids -> MM-EBM-1 -> PA2V2 -> Iriver H120.
It gave about the same peaklevels as the situation without the PA2V2 and the overall sound of the recording was also about the same.
I only do stealth recordings and it would be nice if I could safely use this small amplifier in my rig.
Does anybody know if this is a save and reliable way to add gain to the iRiver H120?
(http://www.electric-avenues.com/ebay/features_pa2.jpg)
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Chris, thanks for your answer.
I talked with the guy who build this amplifier and he said he didn't knew if it could be used as a decent recording amplifier.
That's why I gave it a shot overhere...
I think I will try the amplifier at a not-so-important show and check what it does with the sound, noise, etc. etc.
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Ask him about signal to noise ratio and imput impedance. He should have these answers.
Chris, thanks for your answer.
I talked with the guy who build this amplifier and he said he didn't knew if it could be used as a decent recording amplifier.
That's why I gave it a shot overhere...
I think I will try the amplifier at a not-so-important show and check what it does with the sound, noise, etc. etc.
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Chris,
I checked the guy who makes these amplifiers.
The SNR is about 100dB and the input impedance for the PA2V2 is about 10,000 ohms per channel.
Based on these specs and your reply before I guess this little bastard could do the job?
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Yes give it a shot it sounds like it would work. But now the big question how much gain does it have??
Chris,
I checked the guy who makes these amplifiers.
The SNR is about 100dB and the input impedance for the PA2V2 is about 10,000 ohms per channel.
Based on these specs and your reply before I guess this little bastard could do the job?
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Some more specs about the amp (from http://www.electric-avenues.com):
Most portable devices have an output power under 20 mW (milliwatts). This often isn't enough to enable a decent pair of headphones to reach their full potential. The PA2V2 has an output power of up to 200 mW RMS and makes the music louder by a factor of 610%. The amp can power speakers too, not only headphones. For a small device it can output a lot of power. The frequency response goes from 5Hz to well beyond 40KHz. Critical components are joined with thick, point to point traces for maximum conductivity. The signal to noise ratio (SNR) is 100 dB. Actually, with the volume turned on maximum, and no music playing, there is no static sound or hiss, which is something desirable. Building an extremely quiet, low distortion amplifier was a high priority. An improved power supply filter circuit almost eliminates the 50/60 Hz humming sounds some owners reported when listening with the AC adapter plugged in.
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Like I wrote before, tests I did made it clear that when I open up the gain completely at the PA2V2 and keep the gain-level at the Iriver H120 at 0dB I get about the same peaklevels as without the PA2V2 and the gainlevel of the Iriver at +20dB.
Next weekend I hope to do a live recording and maybe I can test the PA2V2 overthere.
If I got any results I will post it overhere.
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I'd like to add a +T for thinking out of the box. IF it works, kewl you got a new tool, if it doesn't.....back to the drawing board.
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Any chance to play with this headphone amp? I'm looking for some cheap, quiet gain for my stealth rig, and this might cut it. Thanks for any info!
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I make a real 3 wire or 2 wire preamp that is the size of a small pack of cigarettes. For $199 and it has a clip led and high pass filter and a real gain knob that provides a gain range 00- db to +20 db the two wire version is $169.99
Chris Church
Any chance to play with this headphone amp? I'm looking for some cheap, quiet gain for my stealth rig, and this might cut it. Thanks for any info!
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After I taped Radiohead (result can be found at http://www.dimeadozen.org/torrents-details.php?id=109750) last week with only +3dB gain at the iRiver and only +6dB in post I don't think I'll ever will need any pre-amp at all. ;D
I'm not gonna experiment with the PA2V2 anymore.