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I measured the Jadis JA200 Mk.II with my Audio Precision SYS2722 system (see the January 2008 As We See It"). One point to note is that with 10 KT150 tubes packed closely together on the amplifier chassis, the JA200 Mk.II gets very hot. After a couple of hours, the temperature of the top panel by the output transformer was 169°F (76.2°C)!

The voltage gain into 8 ohms was 30.5dB, and the Jadis preserved absolute polarity (ie, was non-inverting). The input impedance was very high, at >500k ohms at low and middle frequencies, and still 300k ohms at the top…

As Nelson Pass, founder of Pass Labs and the XA25's designer, writes in that manual: "The signal path from input to output has been simplified to fewer components. Degeneration, 'the other form of feedback' has been eliminated…

This is what high-quality audio is supposed to do: make the energy coming out of the speakers resemble the energy that went into the microphones, so that wooden instruments sound…

Description: Stereo power amplifier using JFETs and MOSFETs. Inputs: 1 pair single-ended (RCA). Outputs: stereo pair of Furutech binding posts. Power output: 25Wpc into 8 ohms (14dBW), 50Wpc into 4 ohms (14dBW). Peak current: 10A (200W peak into 2 ohms). Bandwidth: DC to –2dB at 100kHz. Input impedance: 47k ohms. Voltage gain: 20dB. Distortion: 0.1% at 25W, 8 ohms, 1kHz. Noise: <50µV output, unweighted, 20Hz–20kHz. Damping factor: 500. Slew rate: 100V/µs. Idle power draw: 2.0 amps at 120VAC (240W).
Dimensions: 17" (430mm) W by 6" (150mm) H by 17.3" (…

Analog Sources: AMG Giro G9, MoFi Electronics Ultradeck turntables/tonearms; AMG Teatro, EMT TSD 75, Hana EL, Koetsu Rosewood Standard, MoFi Electronics MasterTracker cartridges.
Digital Sources: Mytek HiFi Manhattan II, Schiit Audio Yggdrasil DACs; Integra DPS-7.2 DVD player (used as CD transport).
Preamplification: Auditorium 23, Bob's Devices CineMag 1131, Dynavector SUP-200, Lounge Audio Copla JFET-MC step-devices; Lounge Audio LCR Mk.III RIAA, Parasound Halo JC 3+, Tavish Design Adagio phono preamplifiers; Linear Tube Audio microZOTL2.0, Pass…

I measured the Pass Laboratories XA25 with my Audio Precision SYS2722 system (see the January 2008 As We See It"). Before performing any tests, I ran it at one-third its clipping power (see later) into 8 ohms for an hour. At the end of that time, the top panel was warm, at 102.3°F (39°C), and the heatsink fins were hotter, at 122.2°F (50.1°C). The gain at the speaker terminals was to spec at 20.4dB, and the output preserved absolute polarity (ie, was non-inverting).

The XA25's unbalanced input impedance was the specified 47k ohms at low and middle…

Yes, oh yes, Walsh not only had a very successful solo career in the mid-to-late 1970s, in the days of "Rocky Mountain Way," but he also played in a band, now rapidly fading into history, called the James Gang.

Formed in Cleveland in the late '60s, the JG went through a number of lineup changes until becoming a trio in 1968. Signed to ABC Records that same year, they released their debut, Yer Album, in 1969. While that album did moderately well, it wasn't until their second effort, James Gang Rides Again —like the first produced by Bill…

Sir Arnold Bax (1883–1953) completed his fifth symphony in 1932 and dedicated it to Sibelius. Its first performance was conducted by Sir Thomas Beecham in 1934. Have any of our major orchestras ever played it? Not to my knowledge, and after over 40 years, it's about time. At least we have it on disc now, in addition to The Garden of Fand and Tintagel. Lyrita has even more Bax in their catalog.

By now, Raymond Leppard's name…