Wuthoqquan
Head-Fier
- Joined
- May 27, 2015
- Posts
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I've got a Pure II+ (signal black) about three weeks ago. It has gone through some in-depth testing already, with my IEM (Fiio EX1) and headphones (Sennheiser Momentum, Hifiman HE 400i and Fostex TH-X00). I'm certainly more than happy about the performance and flexibility of this amp, however, I'd like to gather more opinions on the behaviour of the gain switch and the resulting impact on the overall background noise whenever sensitive IEM (Fiio EX1 in my case) are connected to the Pure II+.
It would obviously be the norm to set the Pure II+ to the lowest gain, if the intention is to connect sensitive IEMs to it! Indeed, at the lowest gain, there's absolutely no background noise at all that I could ever manage to detect, even without any music playing. The signal is simply noise free and the background silent and pure as it could ever be!
However, with the gain set to medium the scenario with my IEM changes completely, since with this setting there's an audible hum in the background, which may not be perceived with the music playing but absolutely discerable if nothing is playing yet. This background noise gets higher if I set the gain to high.
With my higher impedance headphones, even at the highest gain setting, there's no hum/background noise and everything is totally silent as expected. Therefore, it would seems that the hum is simply the consequence of the improper gain setting, which is above the level acceptable for a sensitive IEM.
Once again, I do understand that the gain setting is there for a purpose, and that IEMs should be listen to with the Pure II+ set to low gain - as advisable/normal. But I'd just like to get a confirmation that it is normal for sensitive IEMs to pick up this hum/noise when the Pure II+ is set to medium or high gain. As a further information, my current source is a Fiio X3 II, connected to the Pure II+ using the interconnect cable provided by Vorzüge. Many thanks!
It would obviously be the norm to set the Pure II+ to the lowest gain, if the intention is to connect sensitive IEMs to it! Indeed, at the lowest gain, there's absolutely no background noise at all that I could ever manage to detect, even without any music playing. The signal is simply noise free and the background silent and pure as it could ever be!
However, with the gain set to medium the scenario with my IEM changes completely, since with this setting there's an audible hum in the background, which may not be perceived with the music playing but absolutely discerable if nothing is playing yet. This background noise gets higher if I set the gain to high.
With my higher impedance headphones, even at the highest gain setting, there's no hum/background noise and everything is totally silent as expected. Therefore, it would seems that the hum is simply the consequence of the improper gain setting, which is above the level acceptable for a sensitive IEM.
Once again, I do understand that the gain setting is there for a purpose, and that IEMs should be listen to with the Pure II+ set to low gain - as advisable/normal. But I'd just like to get a confirmation that it is normal for sensitive IEMs to pick up this hum/noise when the Pure II+ is set to medium or high gain. As a further information, my current source is a Fiio X3 II, connected to the Pure II+ using the interconnect cable provided by Vorzüge. Many thanks!