Have looked around for a suitable amp to suit my requirement but nothing seems to meet it.
I use a Sennheiser HD414 headphone when listening on my laptop but as they are 600 ohm the laptop will just not drive them loud enough.
So, I need a headphone amp that can be driven from the laptop audio out and will match the 414, any idea's?
I use a Sennheiser HD414 headphone when listening on my laptop but as they are 600 ohm the laptop will just not drive them loud enough.
So, I need a headphone amp that can be driven from the laptop audio out and will match the 414, any idea's?
Use a chip amp (LM3886 or similar) using +/- 30V supplies to get the voltage swing you need.
(Is 1W enough?)
You probably don't need that much heat sinking to drive 600R
My $0.02
🙂
(Is 1W enough?)
You probably don't need that much heat sinking to drive 600R
My $0.02
🙂
They are at least 30 years old and definitely 600 ohms. Even the headphone out on my CD player won't drive them to an acceptable level.
probably not going to find too many portable solutions, not in Li battery/USB power without DC-DC built in - dual 9V batteries would give OK swing but not likely better than a wall powered CD player's headphone out
7.5+ W into 8 Ohms would give the Vswing you might want - 600 Ohms only "absorbs" 8/600 of the power, = the headphone 100 mW power rating - actually several times more could be OK for dynamic peaks if that is a continuous power rating for the headphone
so many desk top computer speaker amps, lower power HT amps could at least get loud enough for cheap
although I wouldn't go with switching outputs with your non standard load
so many desk top computer speaker amps, lower power HT amps could at least get loud enough for cheap
although I wouldn't go with switching outputs with your non standard load
Hi,
I think you can use for example a M³ or a CK²III.
I use myself a M³ with variable gain and a HD800 (and HD580) and it can easily drive the HD800.
For high impedance headphones, I think you can't go wrong with either the M³ (which can also perfectly drive low impedance cans) or a cheaper Cavalli Kan Kumisa.
PS: In case you are interested, I'm building regularly those kind of headphone amps, and at this moment I'm selling an M3 with variable gain. You can see it here: http://www.diyaudio.com/forums/vend...num-case-sigma-11-psu-epsilon-12-diy-amb.html
Hope it helps.
Cheers
Thanks thermal runaway! 🙂
If you have some time, and if you want to keep costs the lowest whereas having a high quality amp which can provide high voltage swing, I suggest you to build a CK²III which is simpler to build (only one board is necessary for amp + psu). Price of parts for CK²III are about half the price of M³ parts. You can then find or build a simple and smaller enclosure to put the board in.
This is just an idea... 😉
Cheers
If you have some time, and if you want to keep costs the lowest whereas having a high quality amp which can provide high voltage swing, I suggest you to build a CK²III which is simpler to build (only one board is necessary for amp + psu). Price of parts for CK²III are about half the price of M³ parts. You can then find or build a simple and smaller enclosure to put the board in.
This is just an idea... 😉
Cheers
My creation here would also work:
http://www.diyaudio.com/forums/headphone-systems/229934-version-o2-desktop-amp-oda.html
but it sounds like you may be looking for pre-built rather than DIY. Someone on the forum here could probably build one up for you though. Parts cost with the case, power adapter and PC board is around $250. That is US cost though with parts coming from Mouser and Digikey. I know they charge an arm and leg for shipping to other countries.
14Vpeak = 9.9Vrms into 600R, which would be 163mW. You phone's sensitivity / efficiency is listed as 94dB/mW. That would give 94dB + 10log(163) = 116dB. Both RocketScientist / NwAvGuy
NwAvGuy: More Power?
and Shure
Understanding Earphone / Headphone Specifications
seem to agree that 115dB or so SPL is just as loud as headphones should ever go. Even then it is short duration/exposure from the charts. They both list 105dB - 115dB as a good low/high range. In fact your phones are listed as 100mW maximum continuous power (peaks above that are OK).
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Thanks guys. Suggestions appreciated but they are high end designs and my requirement is, unfortunately, low budget. Looking to spend no more than £50/$75 on this.
Thanks for the caution on SPL. Just to clarify, I just want to get a reasonable level via the laptop, at the moment it's just way too low.
There are some Chinese products on ebay for no more than my budget or even less. Either DIY kits or assembled boards, looks like I may have to go this route.
Thanks for the caution on SPL. Just to clarify, I just want to get a reasonable level via the laptop, at the moment it's just way too low.
There are some Chinese products on ebay for no more than my budget or even less. Either DIY kits or assembled boards, looks like I may have to go this route.
+1 on Avro_Arrow's suggestion! 🙂 I'll bet that is FredFred over on Head-Fi. He is a zen master of small single-chip CMOYs.
Just one LME49720 chip ($3 or so) in a CMOY would work for both channels. The chip is even specified for 600R loads in the data sheet.
With a peak swing of 12Vdc (maximum swing with +/-15Vdc rails) that would be just 12V/600R = 20mA (peak), which is within the 23mA output current shown for an LME49720 chip into 600R. 12Vpeak = 8.5Vrms = 8.5/600 = 14mA (rms). Somehwere around (15V - 8.5V) * 14mA = 91mW of chip dissipation at the full swing per channel, or 180mW total, well within the 400mW or so for the DIP8 package, even with ambient de-rating.
Just one LME49720 chip ($3 or so) in a CMOY would work for both channels. The chip is even specified for 600R loads in the data sheet.
With a peak swing of 12Vdc (maximum swing with +/-15Vdc rails) that would be just 12V/600R = 20mA (peak), which is within the 23mA output current shown for an LME49720 chip into 600R. 12Vpeak = 8.5Vrms = 8.5/600 = 14mA (rms). Somehwere around (15V - 8.5V) * 14mA = 91mW of chip dissipation at the full swing per channel, or 180mW total, well within the 400mW or so for the DIP8 package, even with ambient de-rating.
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100mW into 600ohms is equivalent to 11Vpk.
You can't get that from +-12Vdc (24Vdc single ended).
You will need +-15Vdc (30Vdc) to get to 100mW.
And that is why all your direct Sources can't drive them to 100mW. They don't have sufficient rail to rail voltage.
You can't get that from +-12Vdc (24Vdc single ended).
You will need +-15Vdc (30Vdc) to get to 100mW.
And that is why all your direct Sources can't drive them to 100mW. They don't have sufficient rail to rail voltage.
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