Yeah that sounds crazy. I use senn HD650s and never even approach those levels of drive. Are you hard of hearing?
Thanks,
Nope not deaf, well not yet anyway. I have pretty good hearing.
My go to headphones at the moment are some Sony MDR-10RC.
They do sound very good, some specs are
40 mm dynamic – Dome type
100 dB/mW
40 Ohm at 1kHz
But yeah whilst listening, depending on the mood, normally between 2-3.6VRMS average, and can See voltage swings from 6v to 22v I seen last night on some songs, but that was a quick second burst.
Either I am expecting too much or something isn't quite working correct.
I have tried some B&W P7s and they had a very good bass response, but on the little "make do" amp I am using at the moment, you could tell they would have took a lot more drive. And it is the same with these Sony ones.
Nope not deaf, well not yet anyway. I have pretty good hearing.
My go to headphones at the moment are some Sony MDR-10RC.
They do sound very good, some specs are
40 mm dynamic – Dome type
100 dB/mW
40 Ohm at 1kHz
But yeah whilst listening, depending on the mood, normally between 2-3.6VRMS average, and can See voltage swings from 6v to 22v I seen last night on some songs, but that was a quick second burst.
Either I am expecting too much or something isn't quite working correct.
I have tried some B&W P7s and they had a very good bass response, but on the little "make do" amp I am using at the moment, you could tell they would have took a lot more drive. And it is the same with these Sony ones.
100dB per mW and 40 ohm average impedance.
You're looking at needing 0.2Vrms for 100dB. I listen at an average of probably 75dB most of the time.
3.6Vrms gives you 0.324 mW, which into those 100dB cans = 125dB.
22V peaks are good for ~140dB...
None of that makes any kind of sense unless you are hard of hearing and certainly if you do listen at those levels you will be deaf in no time.
You're looking at needing 0.2Vrms for 100dB. I listen at an average of probably 75dB most of the time.
3.6Vrms gives you 0.324 mW, which into those 100dB cans = 125dB.
22V peaks are good for ~140dB...
None of that makes any kind of sense unless you are hard of hearing and certainly if you do listen at those levels you will be deaf in no time.
I am certainly not hard of hearing, and the levels that I am listening to right now are around 2.5Vrms, and it is barely just louder than an IPod and I don't consider them loud at full power.
The little "bodged" amp I am using at the moment can't deliver that current in to 40 ohm loads, it was designed for 8 and 16.
So either it is the amp that can't drive them, or something else is wrong.
Just coming direct from the PC 3.5mm to RCA, then the "bodged" amp (it is actually the headphone monitor from a Matamp Supernova, but the design is around 40 years old now) and straight to the headphones. Watching the meter voltage now, I can say it isn't what I call loud, loud. The X-Cans V2 I had before certainly went louder.
Does that make any more sense?
The little "bodged" amp I am using at the moment can't deliver that current in to 40 ohm loads, it was designed for 8 and 16.
So either it is the amp that can't drive them, or something else is wrong.
Just coming direct from the PC 3.5mm to RCA, then the "bodged" amp (it is actually the headphone monitor from a Matamp Supernova, but the design is around 40 years old now) and straight to the headphones. Watching the meter voltage now, I can say it isn't what I call loud, loud. The X-Cans V2 I had before certainly went louder.
Does that make any more sense?
Well technically speaking 40 ohms is easier to drive and requires far less current than 8 and 16 ohm loads. 8 and 16 ohms are more loudspeaker territory than headphones. Headphones usually start at around 32 ohms and carry on all the way up to around 600ohms.
What kind of voltage meter are we talking about? The only way to realistically see this kind of things accurately is with a calibrated oscilloscope.
The chips in use on the "bodged" amp are LM380N by TI. This is what I thought but once I get past say six on the pot, clipping all of the time, so it is from what I know to be an impedance miss match. The chip was only designed to be used with 8 or 16 ohm Impedance.
Meter, we are talking Fluke 287 calibrated. Think I agree with the scope comment, but I don't think this little chip will deliver what I am expecting or what the O2 amp can Or the 6120a2.
Meter, we are talking Fluke 287 calibrated. Think I agree with the scope comment, but I don't think this little chip will deliver what I am expecting or what the O2 amp can Or the 6120a2.
Actually the LM380N is capable of considerably more than the TPA6120.
Are you capable of sending sine waves through the headphone amplifier with your source? If you are using a PC listen to some music and set a nice comfortable volume level. Then use a software based signal generator and send through a sine wave, then measure the rms value of the sine wave using the multimeter.
Are you capable of sending sine waves through the headphone amplifier with your source? If you are using a PC listen to some music and set a nice comfortable volume level. Then use a software based signal generator and send through a sine wave, then measure the rms value of the sine wave using the multimeter.
Quick reply as it is late and I am half asleep, doing a quick 20-20KHz frequency sweep (using a software frequency generator), I can acheive at least a clean 6Vrms. It is loud and clean through the cans, listening to the music at half of this seems strained and I can't push it more than around 3v swing before it starts clipping.
Am I missing something here?
Am I missing something here?
Those are deafening levels through 100dB/mW cans. Literally you'd be deaf for any extended period. Even just for short periods.
I was meaning listen to music on the PC, keep the volume control in the same place and then measure the rms volume of a sine wave played through the system at the same volume. Just to get an accurate idea of how loud you actually listen.
I was meaning listen to music on the PC, keep the volume control in the same place and then measure the rms volume of a sine wave played through the system at the same volume. Just to get an accurate idea of how loud you actually listen.
Got, will do that on Monday when I take it all in to work and hook the scopes up. Failing that I am going to build the O2.
The LM380N is designed for 8R loads, if I am putting say a 32R load on it will have say a damping factor of 5 so I would only be looking at getting a 1/4 watt of drive from it.
I understand what you are saying about the levels being deafening, but I can assure you this is in no way loud at all like the readings would suggest it is.
The LM380N is designed for 8R loads, if I am putting say a 32R load on it will have say a damping factor of 5 so I would only be looking at getting a 1/4 watt of drive from it.
I understand what you are saying about the levels being deafening, but I can assure you this is in no way loud at all like the readings would suggest it is.
Okay, think we are getting somewhere now after listening to a FLAC of Johnny Cash Cocaine blues, average output 600mV min to max 0.2v to 1.8v. plenty loud enough, with enough bass.
It confused me slightly how a audio sweep was clean and loud. Think my source music may be a problem. All of my listening is streamed now.
Any sites I could try a uncompressed audio file?
It confused me slightly how a audio sweep was clean and loud. Think my source music may be a problem. All of my listening is streamed now.
Any sites I could try a uncompressed audio file?
I can check this next week, when it is hooked up to scopes, but after doing some further digging around, I am thinking it is source that is the problem.
I do tend to stream songs from you**be for convenience.
It would be interesting to see someone suggest a song and say what Avg, Min-Max Vout they get so I can see just how close of far I am from it.
I do tend to stream songs from you**be for convenience.
It would be interesting to see someone suggest a song and say what Avg, Min-Max Vout they get so I can see just how close of far I am from it.
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