Manley Mahi Power Amplifier

Company Profile

Manley Laboratories in recent years has expanded and thrived under EveAnna Manley's leadership. Our 11,000 sq. ft. building houses our own machine shop, printed circuit board manufacture, audio transformer winding, engraving, and silk-screening facilities.

All custom design, R&D, assembly, testing, and quality control processes are performed with precision and pride at the Manley factory, located just 35 miles east of Los Angeles.

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These cute little guys produce around 40 watts RMS in Ultra-Linear mode or around 20 watts in TRIODE from a quartet of EL84 / 6BQ5 tubes driven by a 6414 dual triode driver and a 12AT7EH input dual triode. The EL84 has been one of our very favorite tubes for many years, extremely long lasting and reliable, and can be considered the smaller brother of the much beloved EL34: really quick-sounding both in the bass and especially in the top end. And of course this has a lot to do with our Manley Output transformer, the same one we build for the Manley Stingray.

Mahi

We have been building EL84 amplifiers for well over a decade. The Manley-branded Tiny Triodes were much acclaimed in the early 1990's. In 1993 after the Manley company split off from VTL, the Manley Tiny Triodes underwent a chassis rework to become the Manley 35 watt Monoblocks soon followed by the 50 Watt Monoblocks. The more powerful Ultra-Linear mode operation became the standard with hard-wired Triode operation or Triode/UL switching available upon special request.

After the introduction of the Stingray Integrated amplifier in 1998, we then went back and incorporated the Stingray's new circuitry design refinements into the 50 Watt Monoblocks. Finally, big bass out of a small amplifier! So, topology-wise, the post-1998 50 watters were the monoblock version of the stereo Stingray, with the additional variable feedback feature. After the introduction of the fabulous Manley Snappers in 2002, it was obvious that we had to update our classic EL84 50 watt monoblocks both cosmetically and feature-wise. Make-over time!

Everyone was always asking us for Triode/Ultra-Linear switching. We listened to ya and put on the Triode-UL switch as standard for the new MAHI's. As are the beautiful german WBT binding posts. Also we increased the B+ rail capacity in a major way. The 50 Watt monos only had around 49 Joules or energy storage in the B+ rail. Now the MAHI's have nearly 180 Joules of energy storage for the B+ rail. You can hear this improvement in the especially in the bass region: tighter, faster, deeper. More is more in this case.

The chassis design is like a mini-Snapper. They are so cute! And of course they come standard as a pair so you get.... "Mahi-Mahi." We believe the MANLEY MAHI's give a lot of value for an affordable price and we think you will be surprised at just how big these little guys sound.

Features and Specifications
• Input Tube: 1 x 12AT7EH large plate Eletcro-Harmonix Russian
• Driver Tube: 1 x 6414 JAN NOS GE or Raytheon branded
• Output Tubes: 4 x EL84M - 6Pi14Pi-EB NOS Russia
• Output Tube Quiescent Standing Current: 20mA
• Set Bias for 200mVDC measured across each 10 ohm cathode resistor
• Gain: 29dB
• Negative Feedback: MIN= 3dB; STD=6dB; MAX=10dB of global NFB
• Input Impedance: 110 Kohm
• Signal to Noise Ratio Ref. 1W: Typically 82 dB A-WGT 20-20K
• Noise Floor: Typically 150µV = -74dBu A-WGT
• Noise Floor: Typically 650µV = -62dBu unweighted
• Dynamic Range: 83dB
• THD+Noise @ 5W: less than 0.15%
• Frequency Response at full power UL mode w/MAX NFB: 20 Hz to 20 kHz FLAT
• Frequency Response at 5W into 5 ohms: 10 Hz to 30 kHz FLAT, -3.75dB @ 100KHz
• Recommended Speaker Load: Optimized for 5 ohms
• Power Consumption (idle): 102 Watts (0.85A @ 120VAC)
• Maximum Power Consumption (at Full Power): 168 Watts (1.4A @ 120VAC)