Description: Two-channel, tubed power amplifier with external power supply. Tube complement: amplifier, two Sovtek 6C45pi, four 300B; power supply, two 6AU4-GTA, two EZ80. Line-level inputs: 2 (RCA). Outputs: 2 pairs each of 3 binding posts—ground, 8 ohm tap, 4 ohm tap. Output power: 20Wpc into 8 ohms (13dBW). Input sensitivity: 1.2V RMS to full output. Input impedance: 100k ohms. Channel balance: 0.5dB. Frequency response: 10Hz–36kHz, –3dB. Minimum load impedance: 3 ohms. Gain: 10dB. Power consumption: 300W.
Dimensions: Amplifier: 17" (430mm) W by 13.5" (…
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Sidebar 1: Specifications
Sidebar 2: Associated Equipment
Analog Sources: Kuzma Stabi S turntable & Stogi tonearm; Thorens TD 124 Mk.I turntable, Jelco 350S tonearm; Denon DL-103, Hana EL, Ortofon 2M Bronze cartridges.
Digital Sources: Apple MacBook computer running Audirvana Plus; LG BD550 BD player (as transport); Halide DAC HD, Mytek HiFi Manhattan, PS Audio NuWave DACs; Western Digital T2 Mirror Drives (2).
Preamplification: Auditorium 23 A23 moving-coil step-up transformer, Heed Audio Quasar phono preamplifier, Shindo Laboratory Allegro preamplifier.
Power Amplifier: Shindo Laboratory Haut-…
Sidebar 3: Measurements
I measured the BorderPatrol P21 EXD using my Audio Precision SYS2722 system (see the January 2008 "As We See It"). I installed the numbered 300B tubes in the correct sockets, as identified in the manual, but I didn't adjust the bias for the two pairs of 300B output tubes, feeling that I should measure the amplifier in the condition it was auditioned by Ken Micallef.
The P21 EXD's voltage gain at 1kHz into 8 ohms was lower than the norm, at 17dB from the 8 ohm tap into 8 ohms, 15.9dB from the 4 ohm tap into 8 ohms, and 14.5dB from the 4 ohm tap into 4 ohms.…
Jason Victor Serinus reviewed the Lamm L2.1 Reference preamplifier in July 2018 (Vol.41 No.7):
Sometimes, great components enter our lives with little fanfare. Thus, by happenstance, did Lamm Industries' L2.1 Reference preamplifier ($22,790) end up in my reference system.
The story began at the 2018 Consumer Electronics Show, in Las Vegas, when John Atkinson and I visited Lamm's oversize suite on a high floor of the Venetian Hotel. Our intentions were twofold: to report on what we heard and saw, and to sniff out products for me to review. We found one likely candidate—AQ…
Soprano/composer Patrice Michaels with Ruth Bader Ginsburg at Glimmerglass in 2016
First there was the epithet, "Notorious RBG," which NYC law student Shana Knizhnik coined in 2013 (in a sly riff on the name of Supreme Court Justice Ruth Bader Ginsburg's fellow Brooklynite and rapper, The Notorious B.I.G.) as the name of her Tumblr site. Then came Derrick Wang's, Scalia/Ginsburg, an opera based on the odd-bedfellows friendship of two SCOTUS justices and opera lovers from opposite sides of the political spectrum, Ginsburg and Antonin Scalia. During the same time period that the opera…
Lovers of high-resolution multichannel sound still don't have it easy. While the two-channel market is replete with snazzy, efficient music servers in stylish boxes, the only multichannel equivalents are Merging Technologies' Merging+Player Multichannel-8, and a handful of stereo devices that are rumored to do multichannel, though no such claims are made in print. To be candid, the latter will play multichannel tracks via USB, Ethernet, or HDMI outputs to suitable DACs (but that's another story), but because they're aimed at the two-channel market, they tend to skimp on the CPU horsepower…
I'm happy to say that DigiBit's Aria Piccolo + is a well-integrated music server that's delightfully capable and easy to use. With suitable attached devices it will play uncompressed (AIFF, WAV) and lossless (ALAC, FLAC) formats up to 32/384 PCM, as well as DXD (32/352.8), DSD64, DSD128, and DSD256 files in glorious multichannel. It was a pleasure to use, and will suit the needs of almost any aficionado of music and multichannel-sound.
Powering the miniDSP U-DAC8
When I reviewed miniDSP's U-DAC8 multichannel USB DAC in September 2015, I found it well worth its price of $299. I used…
Sidebar 1: Contacts
DigiBit, Madrid, Spain. Tel: (34) 915334250. Web: www.ariamusicserver.com. North American distributor: Goerner Audio, 91, 18th Avenue, Deux-Montagnes, Quebec J7R 4A6. Canada. Tel: (514) 833-1977. Web: www.goerneraudio.com
HDPLEX Ltd., 3972 Barranca Parkway, Suite J337, Irvine, CA 92606, Web: www.hdplex.com
Oppo Digital, Inc., 162 Constitution Drive, Menlo Park, CA 94025. Tel: (650) 961-1118. Web: www.oppodigital.com
Sidebar 2: Recordings in the Round
Schubert: Piano Trio 2, Notturno for Piano & Strings
Trio Alba
Audiomax 9032013 (SACD/CD).
I discovered the second movement of Schubert's Piano Trio 2 in E-flat, D.929, in 1975, when it was used as a stately and insistent motif throughout the film Barry Lyndon. Director Stanley Kubrick said that the piece had "just the right restrained balance between the tragic and the romantic without getting into the headier stuff of later Romanticism." Deeply affected by it, I ran from the theater and purchased a recording, though I no…
Stop me if I've said this before (okay, I have): There's much to be said for integrated amplifiers. While separates have long dominated high-end audio, an increasing number of integrated products not only bundle a preamp and power amp, but sometimes add digital inputs of various flavors, phono stages, bass and treble controls (long on life support in audiophile gear), and more.
It's the "more" that interests me—specifically, the access to equalization that can compensate, at least to some degree, for the inevitable problems created by any listening room of domestic size, particularly in…