jamesfleming
Head-Fier
- Joined
- Dec 17, 2012
- Posts
- 59
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- 11
I have a c5 and I'm loving it with my beyer dt770AE phones. However, I'm considering getting a pair of Hifiman he-400s. Will the c5 be powerful enough to power the 400s?
I'm not sure what your volume settings are but:
Sansa Clip Zip (Rockbox 0 dB volume and/or stock firmware, high volume setting, maximum volume)
FiiO L2
C5 (low-gain, volume 25 steps after mute, or 26/63)
AKG K 701 (which is one of the more inefficient dynamic headphones out there)
I'm using a self-recorded binaural recording, which is quite quiet to being with, and it sounds plenty loud to me.
https://dl.dropboxusercontent.com/u/2816447/2013-07-12_-_Binaural_Access_Badge.wav (~27 MB)
^ that's the raw, unaltered audio recording (this is just a sample of the longer recording to keep the file size small-ish)
Yeah, I have quieter songs than that. The problem is also that even though it's loud enough on some quiet songs, the song pushes it to the limit where this is a bit of noise and loud volume change noises. But in fairness, this is probably about 4% of my music.
It is almost all of the time for me too. But it's not switching noises or anything i'm hearing. I put a digitally silent audio file i made on my ipod and sansa and mac with interface. Played the silent file at the same volume i listen to a really quiet song at and there is clealy audible noise. But again, at or near max volume. I'm not saying it's common. It's not. But there are some classical songs and soundtrack music that pushes the c5 to it's limit. That's all. Plus with any player, if you use any eq, you need to cut the gain via eq app to prevent clipping. This makes it worse. But i would bet most people never even hear it. Just saying... I have music on cds that is quiet enough for me to max the c5 and have it no be loud. At this volume using the volume knob gets loud too.If your music is so quiet that you must turn the volume near max, then the recording itself is responsible for generating background noise and that should be present with any amp. C5's volume control features zero-crossing detection, which basically eliminates switching noise as long as there's an active audio signal. If the music is exceptionally quiet, it's challenging for zero-crossing detection to work, and thus, you may hear a slight click during large volume transitions at high volumes. So the "4%" of music figure you quite sound accurate. Personally, I've never run into these issues. Volume is always below 70% for my personal library and various headphones.
[size=medium] I now have my C5. It's a stunning piece of equipment. The finish is superb and I love the contrast with red and black. I took a photo, but I don't think it does it justice as to how the color and sheen show in the light.
It sounds excellent. I love the bass boost with some of my music. I had mine set to a 3db boost which is plenty. I also appreciate the fine volume control and that I don't need to reset it each time I turn it on.
I just don't know if I can appreciate the sound quality improvement over the direct output from my iPhone 5. I haven't yet spent hours listening to the same music with and without the C5. So far, I've compared a number of uncompressed music files with an A/B selector. I have the line out from the iPod Touch 5 (through Apple's lightning adapter) connected to the C5 on A and the headphone out of the iPhone 5 on B. I set the sound of each to the exact same volume and I start both players at the same time, so when I switch sources, there's no detectable change, except for any differences in sound quality. So far, I don't hear any significant difference. I've tried with both the Sennheiser HD598 headphones and with the Westone 4R earphones. Both are very sensitive and low impedance at 103db/32ohm and 118db/31ohm. Is it possible that for these phones, an amp is just not going to make much of a difference? Has anyone else heard a significant improvement with either of the HD598 or 4R? I'll spend more time listening without switching and see if I enjoy listening more with C5.
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Significant, no. But a difference yes. I'm not sure what music you listen to, but I can give you some song examples that show a clear difference between at least the ipod touch 5g line out and headphone out...
It is almost all of the time for me too. But it's not switching noises or anything i'm hearing. I put a digitally silent audio file i made on my ipod and sansa and mac with interface. Played the silent file at the same volume i listen to a really quiet song at and there is clealy audible noise. But again, at or near max volume. I'm not saying it's common. It's not. But there are some classical songs and soundtrack music that pushes the c5 to it's limit. That's all. Plus with any player, if you use any eq, you need to cut the gain via eq app to prevent clipping. This makes it worse. But i would bet most people never even hear it. Just saying... I have music on cds that is quiet enough for me to max the c5 and have it no be loud. At this volume using the volume knob gets loud too.
If the c5 switches when no audio is detected then mine is broken my digitally silenced file plays continuous noise at or near max volume. If i understood you correctly...
In this experiment, you're effectively disabling zero crossing detection.
Zero crossing detection can only work when the amp sees an audio signal. The chip waits up to 50ms for the signal to cross the voltage axis (noise * 0 = 0). Playing pure silence means there's never a reasonable voltage transition, so zero crossing doesn't happen. And at max amp volume, you're multiplying the source noise floor by the amplifier's gain. That's not going to be silent with any amp, unless you have an amazingly quiet source. When playing "silence" at max volume, random source voltage fluctuations near V=0 remain unpredictable within the 50ms detection window (Noise * small voltage = noise). Thus, zero crossing has no opportunity within 50ms to make a silent transition. Try listening to music, or a sine wave while changing volumes. C5 will observe the music signal and volume transitions will be clean. Hope this all makes sense. There's a great pictorial explanation somewhere, which I can't seem to dig up...
This theory is only interesting if you listen to nearly silent recordings at near max volume. Such recordings are often close to their own noise floor, so avoiding noise is challenging regardless of the source/amp/headphones.
Alright, enough engineering talk for tonight