anyone know of a good headphone amp splitter layout?

[Hav]

hi all,

as it says in title...

would be greatly appreciated!

thanks!

[PBE6]

Headphone amps need to deliver power to the headphones, so unfortunately a simple signal splitter won't work by itself. You'll need to split the signal and then send the outputs to separate power circuits.

The LM386 chip was designed as an easy-to-use headphone amp solution for battery powered units, but by all accounts you get what you pay for in performance (did I mention that it's cheap?). There may be improved chips out there that are just as easy to use. Alternatively, you could build multiple copies of a simple circuit like this:

http://sound.westhost.com/project113.htm

Stereo outputs will require two of these for each channel, but mono only requires one and might be just fine for monitoring purposes. You can also try adding a small trimpot (1k?) in line with the headphone amp output as suggested to get the best sound from headphones with varying impedances.

[PRR]

Insufficient information.

Some headphone amps will easily drive multiple headphones. For example, the LM386 can easily drive 16 ohms, so can drive *two* of the now-common 32 Ohm headphones. In old days we used 100 Ohm phones and drove dozens of them with a 4 Ohm loudspeaker amplifier. Just need Y-cables.

What amp? What phones? Links?

[bool]

There are other solutions, more or less advanced - but since the LM386 is so popular among guitar-diy'ers, google look up the "headbanger" headphone amp and mod/reapply to suit your needs. It will most likely drive 3 (three) nominal 32-Ohm phones.

If you want to drive 16-Ohm ear-buds, you will most likely have to use build-out resistors for each stereo output pair (cca. 10 Ohm should do).

Other "easy" solution is a TDA2820 chip. Or two LA4140's. Depending on where you live and what you're after. If you want overkill: TDA2004 or TDA 1510 running at 15 or 16 volts.

[PBE6]

If you run several headphones off of one amp, how do you adjust the volume for each pair individually? I suppose a *very* tiny pot (10 ohms or less) could be used in front of each pair as a voltage divider for volume control. Do they even make those? A quick scan on eBay doesn't seem show anything below 100 ohm, and that's in trim pot form.

Is there a better way? There must be.

[PRR]

> how do you adjust the volume for each pair

That requirement is not in the original question. (One reason I was poking for more info.)

> Is there a better way?

At today's prices, a dual power-amp is cheaper than a dual power pot. So you buffer, split to a lot of small stereo pots, to a lot of small stereo amps.

You can buy this pre-made cheaper than you can collect-up the box knobs and jacks. Sad but true.

[PBE6]

Ah! Good to know.

[bool]

...
You can buy this pre-made cheaper than you can collect-up the box knobs and jacks. ...

"Yes" if you aren't demanding any "special" feature.

"No" if you want f.e. a high-powered driver or a custom eq-ed high-powered driver.

You will pay extra for "high performance". So there's room for DIY, but for anything else, there are ART, Samson and Beer-ringers.

If you DIY, check your grounds meticulously and take care with PSU.

[FUZZZZzzzz]

http://headwize.com/?page_id=105