I was startled. It seemed crazy cheap. At 55 lbs and 55Wpc, that's about $25 per watt and per pound—bargain-basement for a tube amp. Then (I'm not proud of…
I was startled. It seemed crazy cheap. At 55 lbs and 55Wpc, that's about $25 per watt and per pound—bargain-basement for a tube amp. Then (I'm not proud of…
Description: Two-channel, tubed power amplifier. Tube complement: four KT77 (or EL34), two 12AU7, two 12AX7. Maximum output power: 55Wpc into 8 ohms (17.4dBW). THD: <0.1% typical, <1% at rated power. Input sensitivity: 1.0V RMS.
Dimensions: 18" (460mm) W by 5.5" (140mm) H by 17" (435mm) D. Weight: 50 lbs (22.7kg) net, 55 lbs (25kg) shipping.
Serial Number Of Unit Reviewed: ATL-0604.
Price: $1395. Optional cover, $100. Approximate number of dealers: 55. Warranty: 3 years (6 months for tubes).
Manufacturer: Rogue Audio Inc., 3 Marian Lane,…
Analog Source: VPI HW-19 Mk.4 turntable, VPI JMW Memorial tonearm, Clearaudio Victory H cartridge.
Digital Sources: Krell SACD Standard SACD/CD player, Simaudio Moon CD 5.3 CD player.
Preamplification: Audible Illusions Modulus 3a used as full preamp and as phono stage only, Krell KAV-280p line stage.
Power Amplifier: Krell FPB-400cx.
Loudspeakers: Verity Audio Parsifal Ovation.
Cables: Nirvana.
Accessories: Bybee Technologies Signature power purifier, Monster Cable AVS-2000 voltage regulator, Black Diamond Racing Mk.4 Cones, Mapleshade…
Before performing any measurements on the Rogue Audio Atlas, I checked the bias of its four KT77 output tubes. All were running at around 40mA bias current, close to the 35mA recommended by the manufacturer. I tested the Atlas with its output transformer hooked up for 8 ohm operation, as usually supplied by Rogue, and also as wired for 4 ohm operation, as ultimately used by Fred Kaplan in his auditioning. To my surprise, the voltage gain into 8 ohms was the same from both output-transformer windings—26.5dB—despite the 8 ohm tap's greater intrinsic gain. This is…
My experience with Joseph Audio speakers had been limited to show demonstrations, as their prices have always far exceeded my self-imposed ceiling for "…
Description: Two-way, reflex-loaded, stand-mounted loudspeaker. Drive-units: 1" Sonatex soft-dome tweeter, 7" metal-cone woofer. Frequency response: 42Hz–20kHz, ±2dB. Sensitivity: 86dB/2.83V/m, 4 pi (anechoic). Impedance: 8 ohms nominal, 7 ohms minimum.
Dimensions: 15" (381mm) H by 9" (228.6mm) W by 12" (304.8mm) D. Shipping weight: 55 lbs (25 kg)/pair.
Finishes: wood veneer.
Serial Number Of Units Reviewed: 70821 L/R.
Price: $2299/pair. Approximate number of dealers: 32.
Manufacturer: Joseph Audio, Inc., P.O. Box 1529, Melville, NY 11747. Tel: (…
Analog Sources: VPI TNT IV turntable, Immedia RPM tonearm, Koetsu Urushi cartridge; Rega Planar 3 turntable, Syrinx PU-3 tonearm, Clearaudio Virtuoso Wood & Aurum Beta S cartridges.
Digital Sources: Lector CDP-7T, California Audio Labs Icon Mk.II Power Boss, Creek Destiny, Creek CD53 Mk.II CD players; Pioneer DV-333 DVD player.
Preamplification: Vendetta Research SCP-2D phono stage, Audio Valve Eklipse line stage.
Power Amplifier: Audio Research VT100 Mk.II.
Integrated Amplifiers: Creek Destiny & 5350SE.
Loudspeakers: Amphion Helium2…
My estimate of the Joseph Audio RM7XL Special Edition's voltage sensitivity on its tweeter axis was within experimental error of the specification, at 85.5dB(B)/2.83V/m—slightly below the average of 87dB for the 630 or so speakers I have measured over the past 17 years. Its impedance remains above 8 ohms at almost all frequencies, dropping to a minimum value of 7.15 ohms at 200Hz (fig.1). This, in combination with the generally low electrical phase angle, will make the RM7XL a very easy load for an amplifier to drive.
Fig.1 Joseph Audio RM7XL…
But…