objective 2 and beyerdynamic dt 990 pro 250 ohm

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Hello there.

My name is Benjamin Alexander and I'm new to the high-quality audio world. I recently bought the Beyerdynamic DT 990 pro 250 Ohm and I'm in the market for an amp. While I was surfing on the web searching for one I stumble across the objective 2.

So, my questions: Does O2 goes well with my headphones? And if yes, what gain should I choose while I customize my order to get a good amount of volume without loosing quality. The options are: Low (1.0x,2.5x) Medium (1.0x,3.3x) and Standard (2.5x,6.5x).

I currently driving them through my Lexicon Alpha.

If you have other suggestions for an amp I'm open to them.

Thanks in advance :)

PS: I'm listening to music from my PC and rarely I'll listen from my cell phone or pick-up vinyl.
 
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In terms of drive voltage and current your DT990/250 is well within the capabilities of the O2, even when it is running on nearly-dead batteries.

Even at 110dB SPL they only need 2.5Vrms and 10mA per channel, from the spreadsheets below. The O2 on nearly dead batteries is good for around 3.5Vrms. On AC the O2's maximum is around 7Vrms. Either way the O2 can handle a maximum of around 140mA per channel.

You may want to consider getting NwAvGuy's ODAC DAC to drive your new O2:

http://nwavguy.blogspot.com/2012/04/odac-released.html

The same vendors that have the O2 should have the ODAC.
 

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Depends on what kind of preamp you're using with this turntable (and the levels to be expected from the pickup in the first place - seems a typical pickup is the EPC-P24, nominal output level 2.5 mV). Gain for a plain MM phono stage tends to range from about 34 to 40 dB (sometimes more), a full preamp tends to add another 10-20 dB to that.

So best case, total gain about 56 dB --> 1.5-ish volts nominal, not much lower than the Alpha. A 2.5x gain would then net you up to 4 Vrms, which is plenty for a headphone like the DT990-250 (these tend to be perfectly happy with 2 Vrms unless you're semi-deaf).
Worst case, a lil' TC-750 or something with only 34 dB --> 125 mV nominal. There you could easily use the 6.5x setting, yielding output levels that are still going to be more than adequate (is a Clip+ loud enough for you? that's the same ballpark, 800-ish mV).
 
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Keep it simple Benjamin :)

Its pretty much impossible to guess at 'how much gain' you will need. Just be reassured that the O2 can be very easily altered to give as much or as little gain as you need and that it will easily cope with any normal line level signal or signal from a preamplifier.

You mention a Technics turntable. To use that with the O2 (and any other similar amp) means you also need a dedicated phono preamplifier as has been mentioned above.
 
I have no idea what are most the terms you use. :p Clip+ ? :p
A little MP3 player (DAP) made by Sandisk that just about everyone and their dog bought a few years ago. Can run Rockbox, which is super-handy, and by far the cheapest player to do so; technically not bad at all. Sadly now discontinued, presumably critical parts ran out.

Alternatively, I could also have written "Samsung smartphone" or "iPod shuffle/nano".

Anything else unclear, just ask.
 
Can I use the Lexicon Alpha to preamp the pick-up? So, I'll go for the option 1.0x,3.3x to find a middle ground and if it's needed I'll modify it.

sgrossklass you meant if the volume of a mp3 player is loud enough? It was before I got the headphones but after I used them it wasn't. The sound was so nice and clear and and and...compared to my previous headphones and speakers that even though it was pretty much the same dB, it wasn't tiring or painful to my ears.Btw, It's the first good headphones I buy :D
 
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Not familiar with the Lexicon at all I'm afraid. The user specifications should tell you if it accepts a phono cartridge as an input. If it does then it will have a dedicated pair of input sockets that are just for that and nothing else. Cartridges need a lot of amplification as they only but out a very tiny signal (a few millivolts) and also the frequency response of the preamplifier has to conform to a special curve.

https://en.wikipedia.org/wiki/RIAA_equalization
 
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