STATUS - SOLD
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Description :
Consistent with the finest amplifiers, each audio channel of the Proceed HPA2 has its own, dedicated power supply including a separate 663VA toroidal transformer for each channel. The resulting reduction in crosstalk between audio channels provides superior imaging and reproduction of acoustic space. Demands placed on one channel have virtually no effect on the performance of the other channel. A critical factor in the ultimate performance of an amplifier is its "power supply impedance", which can be loosely thought of as the freedom with which the audio circuitry has access to the power it needs, when it needs it. The power supply capacitors (which act as reservoirs of power for the amplifier circuitry) are mounted directly to the printed circuit board rather than using point to point wiring. The layout of the circuitry uses short, thick traces for high current paths. This attention to detail yields an optimal environment in which the Proceed HPA2 may operate to its maximum potential.
Each channel of Proceed HPA2 is individually configurable to receive either balanced or single-ended inputs. This approach allows the user to take full advantage of the greater immunity from noise, RFI, and EMI which balanced transmission of audio signals offers on any preamp-to-amplifier connection where it is supported. At the same time, any or all channels of the amplifier may be configured for single-ended inputs to maintain compatibility with the majority of preamplifiers available today. The gain structure of the amplifier adjusts automatically when different inputs is selected to facilitate this "mix and match" approach. Each channel also uses twelve 150 watt power transistors. These transistors are all individually tested and sorted, and are used in matched sets to ensure that no one transistor bears a disproportionate part of the overall load. The Proceed HPA2 will shut itself down if it senses either the presence of either DC (direct current) or a short circuit at the output, or any unsafe operating temperature. In addition, the AC input to each transformer is fused to protect against any possibility of component-level failure that could draw dangerous amounts of power. Finally, inrush limiting prevents premature aging of power supply components during power-up. Once the power supply has been charged, this in-rush limiting circuitry effectively defeats itself to allow unfettered power supply access to the AC mains.
The Proceed HPA2 is remarkable, and has almost limitless power, outstanding bass response and exceptional resolution. The bass is tight and punchy, yet not overdone. The midrange is well balanced, not too direct nor sunk to the back of the soundstage. Proceed has managed to increase treble extension and detail without the harshness that causes those headaches. The highs have a presence, but do not call attention to themselves. Timbre is true throughout the audio spectrum. The overriding sonic characteristic is the three-dimensional imaging apparent on all types of source material. As a music amplifier, each instrument occupies its own dedicated space within the sound field, making it possible for each note to breathe and be heard with impressive clarity. The soundstage presentation seems to have grown slightly front to back thus allowing previously hidden instruments to gain some of the spotlight. Movie soundtracks are dynamic and riveting with crisp, clear dialogue. Individual instruments sit precisely in space no matter how complex the passage. At 250 watts, the Proceed HPA2 has ample power for any conceivable home listening scenario.
Specifications :
Rated Power Output.........................250 watts per channel RMS at 8 ohms, all channels driven,
.........................20Hz to 20kHz with no more than 0.1% total harmonic distortion
.........................500 watts per channel into 4 ohms
Frequency Response.......................Within 0.15dB from 20Hz to 20kHz
Signal-to-Noise Ratio.......................Better than -80dB (ref. 1 watt, main outputs)
Input Impedance..............................100k ohms (balanced)
..............................11k ohms (single-ended)
Voltage Gain....................................23dB (balanced)
....................................29dB (single-ended)
Input Sensitivity...............................3.17V RMS for full rated output (balanced)
................................1.586V RMS for full rated output (single-ended)
Power Consumption.........................Less than 100 watts in standby
.........................Less than 150 watts when fully on and at idle
.........................Less than 2000 watts maximum
Mains Voltage.................................Determined by the needs of country for which
.................................the unit was manufactured; cannot be reset by dealer or user
Connector Complement....................2 x binding posts per channel
....................1 x 3-pin XLR balanced input connector per channel
....................1 x RCA input connector per channel
....................2 x 0.3cm mini-jacks for remote turn-on and loop-through
....................2 x RJ-45 modular connectors for PHAST communications
....................1 x IEC AC mains connector
Output Impedance............................Less than 0.05 ohms, 20 Hz to 20 kHz
Dimensions(w x d x h)......................45 x 50 x 17 cm
Weight............................................36kg
Miscellaneous :
XLR Inputs.......................................Yes
Made In...........................................USA
Condition.........................................8/10
Product Information :
http://www.proceedaudio.com/ (Manufacturer's Website)
http://www.proceedaudio.com/manuals/HPA2manual.pdf (Manual)
Reviews :
http://www.audioreview.com/cat/amplification/amplifiers/proceed/hpa-2/prd_116100_1583crx.aspx
http://www.audioasylum.com/cgi/t.mpl?f=general&m=111149
http://primeav.audionet.com.tw/0AVReview2002/048/Equipment/Proceed%20HPA2.htm (In Chinese) |
