I don’t particularly have anything against Op-amp based amplifiers, but all discrete is cool both for bragging rights and for sonic reasons. Burson Audio is a big fan of fully-discrete, and the Burson HD-160 is an all discrete headphone amplifier equipped with Burson’s discrete op-amps as well as Burson’s own stepped attenuator unit.
The HA-160, which sells for $699 (and less if you live in Australia), is actually a very good value for money in terms of solid state amplifiers. I’ve been enjoying the sound of the Burson with both the Sennheiser HD800 and the Beyerdynamic T1 headphone, and I truly think that it’s a great amplifier that can compete with amplifiers priced upwards of $1,000.
Operating the Burson is fairly simple, as you basically have one sets of RCA inputs at the back, and two headphone outs at the front. The left headphone out is for high impedance headphones, and the right headphone out is for low impedance headphones.
I’ve been very impressed with the Burson HA-160, and I think that my freshly built 2-ch Beta22 looks like a good benchmark to measure the Burson HA-160 against. The Beta22 is equipped with the same Burson Stepped Attenuator that is used on the HA-160. The Beta22 also gets a nice treatment of Whiplash Audio’s SCSCAg wire for the input signal, WBT silver solder, and high quality 18AWG Japanese copper wire for the power and output wires. The Beta22 is built using the recommended AMB parts supplied by Glassjar Audio. To avoid damaging the output mosfets, the value of R34 and R35 has been changed to 1Ω, following AMB’s recommendation, using high quality Kiwame resistors. The Burson HA-160, on the other hand, is fully stock. Although I’m itching to do some parts upgrades for the Burson, I really have to wait until the review is finished before I can do that.
The system used for the comparison is an Onkyo ND-S1 Ipod transport, Grace m902’s DAC, and the headphone used is the Sennheiser HD800 using a single ended Whiplash TWAg cable terminated in 1/4″ Viablue connector, as well as a Beyerdynamic T1 headphone.
One of the reason that I pitched the two amplifiers together is because the Beta22 has been my long time favorite amplifier. Another reason is how similar the two amplifiers cost. The Burson HA-160 costs $699 shipped to the US. The 2-ch Beta22 build is the cheapest configuration, and depending on parts and enclosure used, would roughly end up costing about the same amount of money.
Of course $700 for the Beta22 is for a self-built amplifier, because a professionally built single ended Beta22 would cost upwards of $1,000. On the other hand, I do think that the Burson HA-160 is a good value at $699, and it would still be worth the price at $1,000 (don’t tell Burson I said that).
The Burson is overall a very nicely built amplifier, and no DIY effort can ever match the quality of the enclosure of the Burson amp. That by itself is a very good selling point, because case work is a very challenging part of a DIY amplifier project. I probably spend more time fabricating the half naked case of the Beta22 than I do soldering the parts on the PCB.
There are also other factors that come into mind in terms of convenience of use. The Burson comes with two different headphone outputs, where the Beta22 only comes with one. One of the biggest worry in using the Beta22 is everytime I want to plug and unplug the headphone. The high power output of the Beta22 makes the output Mosfets liable to damage everytime you slide the headphone jack in and out the socket. Scary stuff, I know. The Burson HA-160 is much more convenient to use on a day to day basis, since you’re never scared that the output Mosfet will blow when you’re evaluating different headphones and need to plug and unplug the headphones frequently.