HistoriCAL Introduction
California Audio Labs is a child of the digital age. Originally, they made a noise by offering modified CD players with tube output stages, a practice for which I found no intellectual justification. On the other hand, the results were successful, even if (probably) due to the CAL units' softening of the harshness of early digital sound.
As digital reproduction has matured, CAL (no relation to me) has consistently offered a wide array of well-received digital products, culminating in the CL-10 (Stereophile, Vol.19 No.11) and CL-15 (Vol.21 No.11) CD…
Sidebar 1: Specifications
Description: Digital/analog converter with 24-bit/96kHz DACs, 8x-oversampling digital filter, and direct-coupled tube output. Digital inputs: S/PDIF on TosLink and RCA. Frequency response: 5Hz-22kHz, ±0.5 dB. Signal/Noise Ratio: 105dB (A-weighted). Total Harmonic Distortion: less than 0.005%. Maximum output voltage: 2.0V RMS. Output impedance: 2k ohms. Minimum load requirement: 10k ohms. Power Consumption: 18W.
Dimensions: 8.5" W by 4" H by 12.5" D. Weight: 10 lbs.
Serial number of unit reviewed: 22020.
Price: $750 (2000); no longer available (2004).…
Sidebar 2: MusiCAL Companions
Main System
Digital sources: Meridian 508.24 CD transport, Meridian 800 DVD/CD transport; Mark Levinson No.360 D/A processor.
Preamplifier: Sonic Frontiers Line-3.
Power amplifiers: McCormack DNA-1 (with Rev.A modifications), Sonic Frontiers Power-2, Power-3.
Loudspeakers: PSB Stratus Gold-i, Revel Ultima Studio, OLS Kharma Ceramique 2.
Cables: Speaker: Straight Wire Maestro II (with PSBs), Harmonic Technology Pro-9 biwire (with Revels), AudioQuest Granite (with OLS Kharmas). S/PDIF digital: Apogee Wyde-Eye, Illuminations D-60. Interconnects, DAC…
Sidebar 3: Measurements
The maximum output level of the California Audio Labs Sigma II was 1.92V, a hair under the CD standard's 2V, and it didn't invert polarity. The source impedance was much lower than specified, at a low 24 ohms across the band, but the processor still wasn't happy driving low impedances. The bottoms of the sinewave clipped at -17dBFS into the admittedly punishing 600-ohm load. I wouldn't recommend using the Sigma with a preamp offering less than a 10k ohm load. In addition, when I played the low-frequency raised-cosine signal that I use to diagnose signal polarity…
EDUARDO PANIAGUA GROUP: Danzas Medievales Españolas
Eudardo Paniagua, flautas de bisel, nay, fujara, psalterio, tromba marina, darbuga, tar, címbalos, caraqueb, cascabeles; Cesar Carazo, canto, viola de brazo; Wafir Sheik, laúd árabe, darbuga, pandero, sonajero; Jaime Muñoz, axabeba, kaval, chalumeau, dulcimer, sonajas; Enrique Almendros, flautas de tres agujeros, gaitas, gaita charra y tamboril, tar, címbaols, campanas; Luis Delgado, zanfona, laúd, dutar, vihuela de péñola, santur, fujara, cántara, darbuga, zarb, bendir, pandera, tambor, tar
M•A M034A (CD only). Todd Garfinkle, prod…
There's an aesthetic dimension to the Manley Laboratories Stingray that transcends high-end audio and borders on modern sculpture—not unlike the E.A.R. V20, which I auditioned in the October issue. Still, the Stingray is by no means an exercise in gimmickry. Form has clearly followed function at every step in the design process, the ultimate goal of which was to fashion a vacuum-tube integrated amplifier with real-world power that defined the outer limits of high-end performance in a functional, affordable, bare-bones package...with a touch of style.
Still, while the Stingray's…
During this time I also experimented with speaker cables with each integrated-amp/speaker combo, alternating between the more passive, linear, midrange-oriented JPS Superconductor Singles and the remarkably rich, triodelike contours of the new, more subjectively voiced Monster Cable Sigma Retros. And, most significantly, I got to upgrade the performance of all my analog and digital components with the new Synergistic Research Designer's Reference2 Master Couplers. These are, for my critical listening purposes and sheer aural exhilaration, an absolute reference point of sonic integrity. The…
Sidebar 1: Specifications
Description: Vacuum-tube integrated amplifier with ultralinear, push-pull output stage. Tube complement, per channel: four EL84s, one 6414, one 12AT7. Line inputs: CD, Video, Tuner, Aux (Record Out, Subwoofer Out available on request). Power output: 50Wpc, optimized for 5 ohm nominal load (15dBW); 25W triode configuration available on request. Damping factor: 10 (equivalent to a source impedance of 0.5 ohms with a 5 ohm load). Bandwidth: 15Hz-40kHz (no limits given). THD at 5W: 0.25%. S/N ratio: 87dB (A-weighted).
Dimensions: 19" W by 6.5" H by 15" D.…
Sidebar 2: Associated Equipment
Analog sources: Rega Planar 3, Dual CS 5000 turntables; Grado Reference Master, Ortofon X5-MC cartridges; Audio Refinement AM/FM tuner.
Digital sources: California Audio Labs CL-20 DVD player, Delta CD transport; Audio Refinement CD player, California Audio Labs Alpha 24/96 tube DAC.
Preamplification: E.A.R. 834P tube phono preamp.
Loudspeakers: Celestion A3, Joseph RM22si, Soliloquy 5, PSB Alpha, Cabasse Aria (by Zalytron Industries, designed by Joe D'Appolito).
Cables: Interconnects: Synergistic Research Designer's Reference2 Master Coupler,…
Sidebar 3: Measurements
Unless otherwise noted, all measurements were made at level settings that resulted in a 1W output with an input of 100mV. This was approximately 1:30 on the Manley Stingray's volume control, at which position the voltage gain into 8 ohms was 29dB. The Stingray's gain at the maximum setting of the volume control was 39.5B.
After one hour of operation at 1/3 power the Stingray was running no hotter than is typical of tube amplifiers. The Manley's input impedance measured a comfortably high 47.2k ohms. The output impedance, however, was also high, ranging from…
