Hi all,
Just trying to wrap my head around this. I build an amp using LM3886 and it can get quite loud when feeding it from the PC line out.
But sounds subjectively quieter if using phone's output on max volume. Are phones not using the Line Out spec?
Is this expected?
Just trying to wrap my head around this. I build an amp using LM3886 and it can get quite loud when feeding it from the PC line out.
But sounds subjectively quieter if using phone's output on max volume. Are phones not using the Line Out spec?
Is this expected?
PC as in mains supply?
Check the earthing.
Also, bit rate and so on of the software, set it to highest.
Set sound level on PC and sound (levels in settings) to max., control volume using the software used to play.
It is usually SMPS and sometimes rendition noise.
The phone does not allow so many controls, so it less easy to make a mess.
Check the earthing.
Also, bit rate and so on of the software, set it to highest.
Set sound level on PC and sound (levels in settings) to max., control volume using the software used to play.
It is usually SMPS and sometimes rendition noise.
The phone does not allow so many controls, so it less easy to make a mess.
Be realistic 🙂 : Phones are fed from a 3.4 to 3.7V DC battery, that SEVERELY limits available voltage out, doubly so if intended to drive significant current/power into a *speaker* load (Phones).
Typical Phone earphone out is around 200mV RMS, at least 100mV guaranteed, but not higher.
Dedicated low voltage rail to rail Op Amps in theory might deliver up to 900mV RMS or so into a highish impedance, say 10k or higher, but won´t drive phones, so they will not be used.
A PC supply has +/-12V available, so a dedicated Line Out (not an earphone one) can easily supply, say, 4 V RMS if asked to, even using "normal" Op Amps, think generic TL072 and such.
Typical Phone earphone out is around 200mV RMS, at least 100mV guaranteed, but not higher.
Dedicated low voltage rail to rail Op Amps in theory might deliver up to 900mV RMS or so into a highish impedance, say 10k or higher, but won´t drive phones, so they will not be used.
A PC supply has +/-12V available, so a dedicated Line Out (not an earphone one) can easily supply, say, 4 V RMS if asked to, even using "normal" Op Amps, think generic TL072 and such.
2b:00.3 Audio device: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) HD Audio Controller
Subsystem: Micro-Star International Co., Ltd. [MSI] Family 17h (Models 00h-0fh) HD Audio Controller
Flags: bus master, fast devsel, latency 0, IRQ 69
Memory at f7800000 (32-bit, non-prefetchable) [size=32K]
Capabilities: <access denied>
Kernel driver in use: snd_hda_intel
Kernel modules: snd_hda_inte
[ 4.061011] snd_hda_codec_realtek hdaudioC1D0: autoconfig for ALC887-VD: line_outs=1 (0x14/0x0/0x0/0x0/0x0) type:lin
Motherboard website says Realtek ALC887
Ah that might be the reason then. I got worried that my 20x gain is not enough and that I created a pants amp.
I was thinking of a pre-amp / input selector project after I finish the gainclone amp.
Put a preset to set the gain...
My PC is set up as above, try that before starting on a new project.
ALC887 is a 7.1 chip, install new drivers while you are at it.
My PC is set up as above, try that before starting on a new project.
ALC887 is a 7.1 chip, install new drivers while you are at it.
Commercial amplifiers use separate simple preamp for mobile phone as source.
Check Cambridge Audio Azur 340A SE schematics.
Check Cambridge Audio Azur 340A SE schematics.
Cellphones are mostly used to drive headphones (not line) directly. There is concern that everybody and our kids are going deaf. Apple and others limit the maximum output of the headphone jack. Yes, often lower than what we call Line. Even if there is a Parental Override on volume limiting, as JM says you can't make real "line" with a 3 volt battery.
Well there are actually quite a few 3.3V DACs that can output 2Vrms, they have internal -3.3V rail generators...
I've used the WM8524 which is one example. But if you have one output jack in a phone for audio which has to
drive headphones, what are you going to do?
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Holy Big Brother Batman! Are we all children now?
I guess my hi fi system would earn me a prison sentence in the EU.
The rules allow personal intervention to increase the levels, its just the out-of-the-box levels that are legislated for, which seems reasonable as the issue was due to reported hearing loss in children and adolescents, whom we have a duty to protect (from themselves).
The alternative would be age-restricting personal stereos and phones, which really is draconian. Come on, think this through people!
The alternative would be age-restricting personal stereos and phones, which really is draconian. Come on, think this through people!
I agree, although there was no such mentality when I was a youth.
A very popular item here is volume restricted headphones for children. I think that's a great idea.
I listened to loud music since I was 12. I used power tools without hearing protection. I worked in the engine room of a ship with zero protective equipment; large, loud turbocharged diesels and compressed air everything. I was young and it was loud.
Predictably, I'm pretty deaf in my old age.
A very popular item here is volume restricted headphones for children. I think that's a great idea.
I listened to loud music since I was 12. I used power tools without hearing protection. I worked in the engine room of a ship with zero protective equipment; large, loud turbocharged diesels and compressed air everything. I was young and it was loud.
Predictably, I'm pretty deaf in my old age.