Transparent headphone amp with balanced pre-outs?
Feb 24, 2013 at 7:46 AM Thread Starter Post #1 of 5

sandslash

New Head-Fier
Joined
Feb 24, 2013
Posts
24
Likes
12
Long story short, things I'd like to have:
  1. Near-zero output impedance and enough power to run most full-size headphones, ie. compatible
  1. Low distortion, flat frequency response, low noise floor, no potentiometer rustling. ie. transparent
  2. Separate volume adjustment for headphone output and pre-amplifier
  3. Maybe more than one input?
  4. Balanced pre-amplified outputs for active monitors, or some method of decoupling inputs and outputs as to not cause switching computer PSU's or component interference to get to the monitors. According to my experience balanced interconnects are the best at it, even though the differential amplification adds a bit of a noise floor in the indistinguishable under -100dB range
 
The DAC I want is the ODAC, as per excellent performance and no-nonsense approach, I'd very much like to support labs offering such a product. However, if it turns out there is no separate headphone amplifier of this quality for a reasonable price (under 500€), I might consider the Cambridge Audio DacMagic Plus as it performs on an excellent level comparable to the ODAC, and has a built-in balanced pre-amp and headphone amplifier. It has a relatively bad 55 ohm headphone output and amplifier though, so it neither might be the Holy Grail I'm looking for, so as for now keep the recommendations to separate analog pre-amp/amplifiers as my intention is to still go with ODAC.

So, open to suggestions! As far as genre preferences etc. go, they don't matter as I don't believe in synergy, my choice of gear will be perfectly synergetic with all kinds of waveforms in the audible range :wink: I generally listen to chill, down-tempo, ambient, instrumentals, trance, house, electronica, breakbeat, progressive metal. If it has melody or meaningful lyrics, I very likely enjoy it.

Oh and of course, if it's some obscure brand nobody else has ever heard of, that's a plus.
 
Feb 24, 2013 at 8:24 AM Post #2 of 5
That's quite the wishlist you have.  I don't think such an amp exists.
 
I'm curious as to why you want balanced outs but are using a SE source, such as the ODAC.  There's only a few amps I know of that take a SE source and convert it to balanced.  One such is the Schiit Mjolnir.
 
Feb 24, 2013 at 8:36 AM Post #3 of 5
Quote:
That's quite the wishlist you have.  I don't think such an amp exists.

 
 
Actually the product exactly like I'm talking about does exist, and it's the Benchmark DAC1 HDR. Unfortunately it's a wee bit out of my price range, so I'm looking at a possible combination of devices that'd reach audibly similar performance for less.
Considering that budget options like Cambridge Audio DacMagic Plus come close and would be perfect with a stronger headphone amp with smaller output impedance, and that the O2 headphone amplifier fullfills all but the pre-out wish, I don't think it's impossible at all! Furthermore, I might not want to go with Schiit as I've heard very negative things about them. Thanks for the reply anyway!

In worst-case scenario I'm ready to go with separate DAC, separate headphone amp, and separate pre-amp. If that's my case, I'm ready to take pre-amp only recommendations too, maybe with a remote. I'd prefer the devices to have some numbers to back up claims, like Ken Rockwell's review on DacMagic Plus and the such.
 
 
Quote:
 
I'm curious as to why you want balanced outs but are using a SE source, such as the ODAC.

 

I would be willing to use an unbalanced DAC and balanced pre-amp, because I don't believe it'd cause any issues. The ODAC in itself has a good power-supply rejection and is transparent with even dirty-ish USB power sources (bad PSU, budget mobos), so my only concern is eliminating ground-loop hum and ground-loop related issues between all three, computer/USB DAC, pre-amp and monitors/speaker amplifiers, which so far only manifests in the speaker-end, and as such is eliminated when speakers are fed balanced. The headphone out has always stayed clean during these issues. I've heard bad PSU and budget motherboard cause audible chirping when connected to gear with their own power supplies and grounds respectively, but not headphones even at full blast. Those issues however have disappeared with balanced interconnects, even if only the last part of the interconnects was balanced.
 
Feb 25, 2013 at 12:40 PM Post #4 of 5
Would the Matrix Mini-i work? Can't find the specs on the amp section, but has multiple inputs (USB, toslink, BNC, AES), coaxial digital out, and both unbalanced RCA and balanced XLR outputs.
 
Feb 25, 2013 at 3:19 PM Post #5 of 5
I thought about it for the longest while. If I recall correctly, it only does 16-bit through USB, which is a bother. I'd have to suffer from emphasized noise floor with digital volume control, or use a S/PDIF output on the motherboard for 24-bit and it's cumbersome firmware. I don't doubt it's a good product on the DAC section too, but without measurements to back up anecdotal claims I would prefer to have an analog input to use a more proven DAC.

It's really difficult finding a headphone amplifier with a balanced pre-amplifier in it with analog inputs (ie. not forcing to use the internal DAC). If you include measurements or objectively proven merits as a requirement, the Benchmark DAC1 and DAC2 seem like the only choices with all of it (I approve of it even though it does have a DAC too, because it measures equally or surpassing transparent requirements).

Well, better start saving I suppose!
 

Users who are viewing this thread

Back
Top