congrats sir john5479!
heres an article by our "resident surplus guru" the venerable
sandawa :
http://news.yehey.com/news3.asp?c=13&i=137030Friday - March 10, 2006
Hi-fi technology turns to smaller, cheaper chip-based operation
1/3/2006 8:01:00 AM
Source : Business World
DAVAO CITY -- Within five years, the high-fidelity audio industry would be shifting to smaller, lighter, and inexpensive electronics, specifically in the case of stereo and multi-channel amplifiers.
Electronic chips developed in recent years that are capable of producing audiophile-grade sound would eventually put aside high-priced amplifiers into vintage category.
This breakthrough has taken root among electronic do-it-yourself enthusiasts and, in a couple of years, would likely be applied in consumer electronics produced locally.
Since early last year, audiophiles have tested and modified their sonic impact tripath amplifiers, the first commercially available audiophile-grade chip-based hi-fi gear brought in mostly through online sources.
The first generation sonic impact T-amp is small, weighs just a few grams without the batteries, with cheap plastic casing and sold for as low as $20 from e-cost, a United States online retail site.
My two units, which arrived in Davao sometime in April, were bought through Amazon.com and cost an average of P2,500 apiece including forwarding charges.
A good number of Manila-based audio enthusiasts, however, got their units earlier, with the majority applying modifications such as changing the capacitors, improving the connectors, and installing a new potentiometer, or volume control knob in layman’s terms.
Many went for better-looking amplifier housing -- handsomely sculpted wood or transparent glass -- which do not result in sonic improvement but certainly attracts both enthusiasts and non-enthusiasts alike.
The sonic impact T-amp is rated at an average output of eight watts per channel at eight ohms, or 15 watts per channel at four ohms, an output at par with many tube amplifiers.
That rating is adequate for normal use and could even meet the demands of dynamic chamber music at loud volume in a typical room of, say, 20 square meters, provided efficient speakers are used.
Efficient reproducers mean those rated at 90 decibels at one meter listening distance and at one-watt amplifier output.
Since the amplifier’s usual electronic components are shrunk into a small chip -- the Tripath TA2024 -- less than one square inch in size, heat sinks are no longer needed.
Efficiency also improves with the signal travelling a shorter path compared with traditional amplifiers. With low output and a new amplifier topology, power is optimized translated to lower consumption without sacrificing sonic quality.
The T-amp needs a separate power supply, though, since it was originally aimed at the mobile audio market.
It operates using eight penlight batteries, which could last several hours of continuous playing depending on preferred loudness level.
Without the batteries, it needs a regulated 12-volt power supply converter to be plugged into the standard 240-volt power line.
The converter rating should preferably be at three amperes to maximize the amplifier’s rated output.
Such preference is derived using the general formula of voltage multiplied by amperage is equal to output in watts, in this case 36 watts or slightly over the 30 watts total maximum output of the unit.
Initially, local audiophiles claimed it is best to hook the T-amp to a 12-volt lead acid battery to perform best, but in my experience, using a 12-volt regulated converter does not result in sonic degradation.
This is confirmed by latest observation among foreign audiophiles as per posts in audio discussion fora. Since I have two units, one has a regulated 12-volt supply and the other a 13.6-volt converter, which some listeners in the US said results in better low frequency response.
On the first day I received my two T-amps, I tested one unit against a 30-kilogram (240 watts per channel at 4 ohms) Sansui AU-XII amplifier, originally priced at ¥275,000 in 1983.
I arranged them to appear as if I was comparing the Sansui with another amplifier, an Accuphase E-302 (180 watts per channel at four ohms) using similar sounding speakers: ElectroVoice Interface A and Denon SC-104.
My two children who came in from school had common observation: there was no difference at all when the volume of the two units were at room level.
Increasing the volume several notches higher, the children said the Sansui was slightly better sounding, not knowing it was actually a small 15-watt T-class amplifier not the Accuphase, which was compared side by side with the Sansui.
My wife who came in later said even at high volume, the sound quality from the two amplifiers was the same. Later, they were surprised to find the one pitted against the Sansui was a small amplifier that looks more like a child’s toy.
In the succeeding days, friends who would visit me were also amazed by the T-amp’s performance considering they were used to hearing only monster amplifiers.
In my opinion, the sonic impact T-amp’s sound is significantly superior compared with entry- to mid-level amplifiers, whether new production or vintage types.
Its sonic character could be described as in between the solid state’s fast, clinical response and the tube’s sweet and gradual sonic decay.
While it puts out clean and pleasing sound, the drawback is in reproducing the dynamics required by some classical and show-off pieces at loud volume.
A listener into rock, jazz or the usual popular music categories would be happy with this amplifier, especially when hooked to mega-loud performers from Klipsch, Altec Lansing, JBL, ElectroVoice, or Cerwin Vega.
By this year, higher-powered amplifiers using newer Tripath chips would likely achieve what the monster vintage amplifiers -- those with continuous outputs of at least 200 watts per channel -- could do.
The Tripath chip’s ascent as an audiophile-grade amplifier component started last year when a San Diego, California-firm sonic impact technologies marketed its Tripath-driven amplifiers aimed at the mp3 player market, specifically users of Apple iPods.
Some early buyers accidentally hooked their small plastic toys to larger speakers and the rest is sheer serendipity.
Last January, TNT Audio , Europe’s leading audiophile Website, reviewed sonic impact T-amp and found its performance comparable with solid state and tube-based amplifiers costing thousands of dollars. That review resulted in a sudden demand surge causing a temporary supply shortage.
Hundreds of local audio enthusiasts were among the first wave of T-amp buyers early last year with some enterprising groups accepting advanced orders in Manila at P3,500 per unit.
A few realized they could buy cheaper and went straight to online distributors.
That costs less than P2,500 per unit, coursed through a local forwarder, with delivery time from one to two weeks.
Acquiring the original sonic impact T-amp at less than $30 nowadays, however, could be difficult after the company introduced recently a revised version of the original amplifier now priced at $139 P7,367 at $1:P53) per unit.
Except for a better-looking case and improved connectors, all other specifications of the new model are the same as the old unit.
Dr. Adya Tripathi, the Indo-American engineer behind the Tripath chips noted as far back as 2003 that chip-based amplifier technology would dominate the consumer electronics subsector before the end of this decade.
Mr. Tripathi’s company, Tripath Technologies, Inc. based in San Jose, California, started operating in the mid-1990s.
The latest feedback indicates the price of Tripath chips has fallen from over $10 (P530) each for a low-powered amp a couple of years back, to less than $5 (P265) each now for high-powered amps.
The latest of the company’s amplifier chips puts out 400 watts output and designed primarily for subwoofer application.
************************************
by: HERNANI P. de LEON
Mindanao Bureau Chief
Business World Internet Edition
