Here's a variety of Headphone amp suggestions from our VP Mark Cohen as of July 2017– keep in mind he has his own biases. Some units are amps only; others combine both DAC and amp. Prices in USD, and may not be accurate. This is not meant to be the Holy Grail of information; just to help point the buyer in the right direction. In no particular order.
NOTE: if you have a 200 Ohm LCD-4, then you need a more powerful amplifier than normal. Take a look at the Headamp GS-X MkII, Bryston BHA-1, Chord Hugo TT, Chord HUGO 2, Pathos Acoustics Inpol Ear, etc.
Other special use case products:
If you need Linux OS support, get the Prism Sound Callia
If you have a Windows desktop computer (with PCI card slots), then get the Matrix Digi X-Hi USB PCDIe card for much, much better sound from your Windows machine than the built-in USB ports.
Cyrus ONE is a great integrated 50 watt amp, with phono preamp, and a very good sound headphone amp for a very reasonable price. Nice if you need a “complete” product.
Chord Hugo TT – Excellent. Different DAC sound than others due to their own FPGA implementation. $4,500. We’re big fans of their DACs. The Chord Hugo 2 and Mojo are great, too. If you have the financial resources, then give the DAVE a listen. If you have an LCD4 and need a portable amp/DAC, then the Hugo 2 is your best choice (sounds amazing with the LCD4). And you should try the LCDi4 with it.
Pathos Aurium – Hybrid tube and soild state (MOSFET), more analytical sounding than the WOO (see below), has great features like Gain & Balance controls and balanced in/out. $1400. Amp only, no DAC. Maybe partner this with the Matrix X-Sabre DAC ($1,099).
Pathos InPol Ear – great fully balanced amp to drive anything, but also functions as line level preamp and DAC with streaming. Uncheap at $4500+, but very nice.
Burson Conductor Virtuoso 2 DAC and headphone amps. Like the Benchmark listed below, this is a DAC/preamp/headphone amp in one box, and is sonically excellent. $1995. It will drive just about anything! And it has a really cool front panel display with remote control. Just add a power amp and speakers, and you’ve got a great home system.
SPL Phonitor 2 – has a great feature - spatial controls! Plus, 3 inputs, and balanced in/out. $2k, and can be used as a line stage preamp. I’d use this with the Audeze XC for studio mixing. Cannot drive the LCD4. But the new Phonitor E in balanced mode can.
Nagra HD DAC. Frighteningly good. It you have too much money, you seriously need to demo this product. Don’t say we didn’t warn you.
Headamp GS-X mkII. Great balanced amp for driving the LCD4s!
Questyle CMA-800R. Very good amp. But we also love the new CMA 400i driving the LCDi4 in-ears in balanced mode.
Pass Labs HPA-1. A great headphone amp with line level preamp. Beautiful sounding. Maybe not quite enough gain for the LCD4 if you like playing REALLY LOUD.
Prism Sound Callia DAC/amp – Great product. Linux support! About $2000.
Cavalli Audio – An excellent choice, but we haven’t heard the latest versions.
WOO Audio WA6-SE – great tube sound if you want to be in SET heaven, not very expensive. $1200. We haven’t heard their WA-7 Fireflies yet.
Matrix M-Stage HPA-3 U – a best buy at under $400 (via Amazon). This appears to be similar in circuit design to the Lehmann headphone amp from Germany.
Mytek Brooklyn & Manhattan II. Great products. They also do MQA.
Matrix Audio Quattro II Amp/DAC – Once again, a best buy at only $899. This is probably your best choice for a balanced output headphone amp with DAC at less than $1,000.
Cyrus Audio Cyrus ONE – a great headphone amp and integrated amplifier (even a phono preamp and Bluetooth are included!). About $1000.
Bryston BHA-1. Choose this if you want a better balanced output amp than the Matrix Quattro listed above.. $1,395. This is also one of the few amps with a balance control (like the Pathos & SPL) – more necessary than you might think as everyone’s left and right ears are different. And this is a powerful amp for the LCD-4.
Lehmann Audio Linear – A very good sounding amp, $1100
ALO – check them out if you’re a tube fanatic and don’t want the WOO WA6-SE
Oppo HA-1 – It has a great DAC and headphone amp built-in! And we really like the HA-2 amp/DAC – good product!
Norma Audio – Very good, and has DAC and line level preamp.
Schiit Mjolnir – If you can pronounce the name, then this is a very good balanced amp. $749 direct from them.
Audiovalve Luminare – Excellent, especially if you have both high and low impedance headphones and/or Stax Electrostatics. No DAC. About 3,000 Euros.
Benchmark DAC3 HGC (2017 version) – unlike many of the other units, this is a full-function analog preamp, headphone amp, and DAC. $2k.
PS Audio DirectStream Jr DAC
Resonessence Labs Mirus DAC
…these are the models we use at our trade show demos.
Portable battery powered headphone amp+DAC
Sony PHA-3 – Excellent (ESS Sabre 9018 DAC), AND balanced outputs! $995
Sony PHA-2 – Very good, if you don't want to invest in the PHA-3 – does DSD. $500
Oppo HA-2SE – An elegant solution in a slim package.
Chord Mojo and Hugo 2 – We love their DACs, they use a unique topology, and the amps sound great too.