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Reviewer:
Srajan Ebaen
Financial Interests: click here
Source: 1TB iMac (AIFF) into Weiss DAC2
Preamp/Integrated: Wyred4Sound STP-SE [on loan]
Amplifier: FirstWatt F5 and J2, Yamamoto A-09S, MiniWatt N3
Speakers: ASI Tango R, Voxativ Ampeggio [on reivew]
Cables: Complete loom of ASI Liveline
Stands: 2 x ASI HeartSong 3-tier rack, 2 x ASI HeartSong amp stand
Powerline conditioning: 2 x Walker Audio Velocitor S
Sundry accessories: Furutech RD-2 CD demagnetizer; Nanotech Nespa Pro; extensive use of Acoustic System Resonators, noise filters and phase inverters, Advanced Acoustics Orbis Wall & Corner units
Room size: The sound platform is 3 x 4.5m with a 2-story slanted ceiling above; four steps below continue into an 8m long combined open kitchen, dining room and office, an area which widens to 5.2m with a 2.8m ceiling; the sound platform space is open to a 2nd story landing and, via spiral stair case, to a 3rd-floor studio; concrete floor, concrete and brick walls from a converted barn with no parallel walls nor perfect right angles; short-wall setup with speaker backs facing the 8-meter expanse and 2nd-story landing.
Review Component Retail: $2.299 | €1.439 each including postage to US and EU respectively

"The very best we make." That's how Burson Audio in Melbourne solicited me for their 160 components. At present that range consists of an impedance buffer in either XLR or RCA configuration; and one each head, integrated, pre and power amplifier. Since 1997, DIYers have known this Australian team for its fully discrete op amp. By 2003 a low-noise super regulator followed. The original op-amp upgrade* for inferior IC chips that are so prevalent in consumer hifi has now morphed into its 2nd generation. So has the all-discrete super regulator.
  *Burson's can replace the dual op-amps AD712 and 827; C4570; JRC4580, 5532, 5532D and 5534; LF353 and 833N; NE5532, C4520, C4570; NJM2068D, 2114, 2214D, 4558, 4558D, 4560, 5532 and 4558P; OP275; OPA2132, 2134, and 2604; RC4558D 4558P; TL052 and 072; and single op-amps like NE5534, LT1122, OPA627 and 604; and AD811 and 844.
Eventually Burson launched its own 100 Series components. Those were bound to showcase their in-house solutions which had enjoyed success with DIY and OEM for years. Today's more upscale 160-Series machines contain the latest implementations of all which Burson as manufacturers of discrete circuit modules have learned from OEM and user feedback.
Overall parts pedigree for Burson's best separates is high. Here one gets 0.1% tolerance military-grade Dale resistors; Elna, Silmic and Wima capacitors; and over-spec'd ultra low-noise custom toroidal power transformers. The class A preamp runs a very high input-impedance FET buffer for optimized low-level sensitivity and offers 15dB of voltage gain.
RMS voltage swing is a potential 25V/80V peak. Output impedance is 20 ohms. For signal attenuation, Burson has built its own dual-mono 24-step volume control which places a single resistor into each side's signal path for any given level. The power supply runs dual voltage rails and one power toroid per channel. Input sensitivity for a 1V output is a high 285mV.


A-weighted S/N ratio for the overall circuit is better than 100dB and THD is <0.002%. There are three inputs and a single output, all of them RCA. Dimensions for the clear-anodized case are identical to that of the matching power amplifier—430 x 100 x 360mm WxHxD—and weight is a substantial 12kg (15kg for the amp).
The 160 preamp is bare-boned on creature features. There's only one pre-out and no remote. But, it retaliates with an attractive sell price of €1.439—delivered to the EU; $2.299 to the US—and class-leading construction that belies the sticker.


It bolts together 6-mill lipped aluminum extrusions with 90° metal brackets on the lips just like picture-hanging channel frames. The end result are plain-looking vault-type cases with good self damping and monolithic heat dissipation which far exceed the thin bent sheet-metal affairs that are ubiquitous into much higher price ranges.


The differential class A/B dual-mono stereo amplifier is unusual by providing high-level inputs. These auxiliary speaker terminals tap into the current power buffer and bypass the class A FET input. Thus connected, the PP 160 becomes a booster amplifier for low-power tube amps. Burson asserts such transparency for their output stage that the harmonic fingerprint of the preceding amplifier—most likely a SET but up to 25 watts of input power are permissible—will be passed unaltered yet 'turbo-charged' to 95/180wpc into 8/4 ohms. The Nelson Pass FirstWatt F4 amplifier with current but no voltage gain proposed a similar application. The F4 could necessitate that a SET's output be stabilized with a small load resistor. The PP160 implementation does not.


Simply connect the speaker outputs of your low-power tube amp to the speaker inputs of the Burson amp, select the latter with the rear-mounted toggle switch, then connect your speakers to the regular output terminals. As proud owner of Shigeki Yamamoto's stupendous—and for many applications under-powered—A-09S direct-heated 300B SET, I was all set to boost its 8-watt output and put Burson's confident claim to the test.


Due to low-noise Burson custom regulators and an ultra low-noise 380-watt power toroid with less than 1% core loss, the PP160 is said to achieve an impressive 118dB S/N ratio (the line input offers 96dB). Each unit undergoes five stages of tuning on the bench and over 100 burn-in hours before it leaves the Burson facilities. Frequency response is 10Hz to 120kHz ±3dB, gain 29dB.


In toto, the no-nonsense design brief for both components was extreme transparency. That relies on circuit speed aka bandwidth, very low noise floors and over-spec'd power supplies. Burson's contention is that once these basics are handled discretely—they harshly reject chip-based op amps and off-the-shelf regulators as third-rate operators and fit only for cost savings—solid-state circuits will sound as they should: very good.


Lucky for shoppers, Burson's DIY roots enforce a mind set that's clearly adverse to frills, bling and steep stickers. As even a cursory glance at their components suggests, these folks are about stripping the fat and slashing excess. Power remains conservative, chassis are stereo rather than mono, power supplies are internal and displays, remotes, standby switches and multiple color options don't exist. One might even conjecture that the men from Down Under deliberately filled a niche that was vacated when the original hair-shirt Brit integrated went under and was reborn with fuller features, fancier industrial designs and higher prices.


Classic Brit-Fi from Oz then? Considering the first Anglo Saxon settlers on this continent, it's perhaps not as farfetched as it reads. How would it all translate into listening impressions?