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Although I reviewed the original version of this elegant South Korean streamer not too long ago, in the December 2021 issue, it has already been updated. The RS250A ($2695, footnote 1) replaces the RS250's ESS ES9038Q2M two-channel DAC chip with the higher-performance ESS Sabre ES9028PRO chip and now supports PCM data formats up to 32/768 and DSD formats up to DSD512.

MoFi Distribution sent me a sample of the new RS250A. I installed the Rose HIFI app on my iPad mini and connected the RS250A to my NetGear…

After break-in, I plugged my studio's monitor controller into the balanced analog inputs on the primary speaker using standard XLR cables. (The Neutrik universal-balanced sockets on the 4329Ps, which are common on pro and prosumer equipment, also allow a ¼" TRS connection.) I switched the input to balanced analog and cranked the volume up all the way to listen for hum or hiss. Hearing none, I turned the volume back down to a civilized level and listened to some music played back from the studio computer.

My downstairs space is about 10' × 20', with an 8' ceiling. I set up the…

Description: Two-way bass-reflex, standmount digital loudspeaker system with integrated D/A conversion, class-D amplification, and on-board DSP. Drive units: 1" compression-horn tweeter, 8" paper-cone woofer in a front-ported enclosure made of ¾" MDF finished in wood veneer. Crossover frequency: 1675Hz. Frequency response: 28Hz–25kHz (–6dB). Dispersion: 90° horizontal, 60° vertical (2kHz to 15kHz). Digital inputs: Bluetooth 5.3, Wi-Fi, Ethernet, S/PDIF (TosLink), USB2 Type B, USB-A (for attaching a thumb drive). Analog inputs: One pair balanced (XLR/ TRS combo…

Analog sources: Technics SL-1200MK7 Anniversary Edition turntable, Shure V-15 Type III cartridge, Pro-Ject Phono Box RS2 preamp.
Digital sources: Apple iPhone 7S, Lenovo ThinkPad L530 laptop, Oppo DV-981HD universal disc player.
Preamplifier: Benchmark LA-4.
Power amplifiers: Benchmark AHB2, LSA Warp 1.
Loudspeakers: Amphion Two18, B&W 808.—Tom Fine

I used DRA Labs' MLSSA system with a calibrated DPA 4006 microphone to measure the behavior of one of the JBL 4329Ps in the farfield and an Earthworks QTC-40 mike for the nearfield responses. Before I started the testing, I connected the 4329P to my network router with an Ethernet cable and opened its local webpage. The review sample was running firmware version 0100.1685.0x1010f. I performed a factory reset and checked to see if a firmware update was available. It wasn't.

The Roon app's audio settings window indicated that the network-connected speaker had…

I like this goodwill greeting because it sets a mindful tone. I presume that sentiment was issued by one Mr. He Qinghua, because farther down the page, it states, "All Audio-GD's products are designed and developed under the leadership of Mr. He Qinghua." When I began my auditions, I took this salutation as an advisement, making it my plan to study Audio-GD's Vacuum HE1 XLR line-level preamp with as much wisdom as I could muster and the enthusiasm of high…

Compared to the HoloAudio Serene
For this next part, I connected the HE1 to my solid state reference power amplifier, the Parasound Halo A 21+. This and all subsequent comparisons were made single-ended because the Lab 12 Pre 1 has only single-ended inputs and outputs and I wanted to use the same Cardas Clear Beyond cables for all comparisons.

Driving the Falcon Gold Badge speakers, the powerful Parasound offers a more balanced, evenly rendered contrast structure, never too soft or hard. Music does not get loose or blurred at the frequency extremes.

With the Parasound…

Description: Fully balanced stereo, tube-rectified, line-level preamplifier with 11dB maximum gain, a regenerative power supply, and a 100-step volume control with an exponential characteristic. Tube complement: six 6H2N-EB twin triodes, four 6U4N-EB half-wave rectifiers, all Russian. Inputs: 3 balanced (XLR), 2 single-ended (RCA). Outputs: 2 balanced (XLR), 1 single-ended (RCA). S/N ratio: >96dB (2V input, 2V RMS output, unweighted). Output impedance: <300 ohms (RCA). Power consumption: 40W.
Dimensions: 17" (430mm) W × 5" (132mm) H × 18" (450mm) D incl…

Analog sources: Dr. Feickert Analog Blackbird turntable with My Sonic Lab Ultra Eminent Ex moving coil cartridge. Sutherland Engineering SUTZ transimpedance step-up device. Tavish Design Adagio phono stage.
Digital sources: Roon Nucleus+ music server; Denafrips Terminator Plus DAC.
Preamplifiers: HoloAudio Serene, Lab 12 Pre 1, PrimaLuna EVO400.
Power amplifiers: Parasound Halo A 21+, Elekit TU-8900.
Loudspeakers: Falcon Acoustics LS3/5a Gold Badge.
Cables: Digital: AudioQuest Diamond USB. Tonearm and interconnect: Cardas Clear Beyond.…