January 26, 2020 § Leave a comment
The Parasound Halo JC 1+ is remarkably quiet and is the first commercially built product to employ active high-frequency noise filtering with Bybee Music Rails, eliminating input stage noise that compromises sound quality. Curl’s newly-designed driver stage employs a cascode circuit with greater open-loop bandwidth and increased linearity. In another first for the JC 1+, the input and driver stages reside on FR-408 printed circuit board material. Until now FR408 was used in super-computer and aerospace applications. The input-stage power supply is totally independent from the main power supply. Its R-core transformer isolates sensitive circuitry from high-frequency power line noise. This input stage power supply employs quiet high speed/soft recovery diodes and 22,400 uF filter capacitance, to deliver +/- 112 VDC rail voltage, virtually eliminating distortion. Premium Wilson Audio REL capacitors use a proprietary design, which resists micro vibrations that typically degrade the sound quality of other caps. The addition of an XLR Loop Out as well as a 12V-trigger/delayed-turn-on improve the connectivity and utility when multiple JC 1+s are used in bi, tri, and quad amp configurations.
January 25, 2020 § Leave a comment
“The power amplifier is, well, a power amplifier. Aside from a large front-panel meter, with some fun color options, it has no special controls. The only practical feature I’d flag is that the amp has XLR inputs only, but few audiophiles today are going to use RCA cables in any case. Like all good power amps, you put it in place, hook it up, turn it on, and forget about it, although you will want to run a mini-cable between the preamp’s 12V trigger output and the power amp’s trigger input so that the amplifier turns on automatically with your preamp.
This is not just an ordinary power amp, however. When D’Agostino uses the word “power,” he is not kidding. The Progression stereo power amp is a 125-pound unit that can deliver 300 watts into 8 ohms and 600 watts into 4 ohms. Its gee-whiz technical features include 42 output transistors, a nearly 3000VA power-supply transformer, and 400,000 microfarads of power-supply storage capacitance, and it can optionally be hooked up to a 240V AC socket.”
January 16, 2020 § Leave a comment
“The Adcom amplifier’s bass quality is more of the “rolling thunder” variety, making it difficult to hear individual bass strings vibrating. The $4495 Cary SA-200.2 ES and $2999 Benchmark AHB2 amplifiers far outperform the Adcom in the bass, being much more resolved and linear into the deepest bass. The 12 Watt single-ended Valvet amplifier also has greater resolution down low, although it does not offer a challenge to the macro dynamic prowess of the Adcom’s 300 Watts. The Magicos are 4 Ohm speakers.
The GFA-555se offers excellent dynamic performance. One can clearly appreciate the pop or attack when a drum stick hits the snare or hear a rim shot. Low level dynamics, the quiet shifting of intensity of a voice, or the way Brad Paisley changes the force with which he plucks almost every guitar string, is apparent and enjoyable.”
January 14, 2020 § Leave a comment
Across the frequency spectrum, the Tung Sol KT-150 output tubes produced lightning-fast transients and startling dynamics. Soundstaging was immense in size and imaging within the sound stages was precise and clearly delineated. With high quality 2-channel stereo recordings, wandering into the walk-through 3-dimensional musical landscapes produced by the VT80 SE was a breathtaking pleasure.
Shortcomings…? The VT80 SE’s 4Ω outputs are grounded. In the owner’s manual, ARC notes: “Avoid wiring and speaker switching systems that have a common ground wiring or switching of the amplifier output.” After connecting the 4Ω taps to half dozen different pairs of speakers, I consistently heard a low-level ground hum. Although the hum didn’t overpower the music, it was still *there*; and not in a good way.”
January 9, 2020 § Leave a comment
The back panel is recessed, which does make plugging in cables and interconnects a little trickier, but not by much. Honestly, the unit is so compact that I found it easy enough to spit it around, make the connections from the front, then spin it back, although if you don’t have enough slack in your wiring, this might not be an option.
Front panel controls are minimal, consisting solely of navigational buttons, Enter, and back, as well as a power button and one that cycles through inputs. All of these buttons save the power button are touch-sensitive, which adds a touch of class that’s honestly a few steps up from what I would expect in a $1,000-ish stereo integrated amp.”