Amplifier 擴音機 / MANLEY / Mahi
Mahi

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

Introduction

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.

Specification

Manley Mahi:

Input Tube: 1 x 12AT7EH large plate Eletcro-Harmonix Russian
Driver Tube: 1 x 6414 JAN NOS GE or Raytheon branded
Output Tubes: 8 x EL84 Ships with Russian NOS EL84M (aka 6Pi14Pi-EB) We are out of Ei 6BQ5.
Output Tube Quiescent Standing Current: 25mA
Set Bias for 250mVDC measured across each 10 Ohm cathode resistor
Input Impedance: 110 kOhm
Negative Feedback: MIN= 3dB; STD=6dB; MAX=10dB of global NFB
Gain:
TRIODE/UL
FB MIN: 30.7 dB 32.1 dB
FB STD: 28.5 dB 29.1 dB
FB MAX: 26.1 dB 27.1 dB
Input Sensitivity for Maximum Output Power: defined as input voltage required in order to produce maximum power output reaching 1.5% THD @ 1KHz
TRIODE/UL
FB MIN: 175mV 155mV
FB STD: 312mV 340mV
FB MAX: 480mV 566mV
Input Sensitivity for 1W into 8 Ohms: 61mV 53mV
Maximum Output Power: defined as power output reaching 1.5% THD @ 1KHz
into 5 Ohms: TRIODE UL
FB MIN: 18W 20W
FB STD: 27W 42W
FB MAX: 28W 46W
into 8 Ohms: TRIODE UL
FB MIN: 14W 24W
FB STD: 24W 40W
FB MAX: 25W 41W

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
Will Scratch Your Floor: Use pennies under pointed feet to avoid marring cabinetry. Try quarters if you are in upper tax brackets. The bargain performer would be nickels. Paper currency does not function as well. Euro coins work 1.54 times better. Concrete pavers or wooden chopping blocks serve fine for amplifier platforms.
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
Output Impedance:
TRIODE / UL
FB MIN: 2.43 Ohms 3.10 Ohms
FB STD: 1.47 Ohms 1.67 Ohms
FB MAX: 0.90 Ohms 0.95 Ohms
TRIODE / UL
FB MIN: 3.29 2.58
FB STD: 5.45 4.78
FB MAX: 8.90 8.43
Damping Factor:
TRIODE / UL
FB MIN: 3.29 2.58
FB STD: 5.45 4.78
FB MAX: 8.90 8.43
Power Consumption (idle): 102 Watts (0.85A @ 120VAC)
Maximum Power Consumption (at Full Power): 168 Watts (1.4A @ 120VAC)
Operating Mains Voltage: Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.
Operating Mains Voltage: changeable with power transformer re-wiring and fuse value change.
Mains Voltage Frequency:
Mains Fuse 100-120VAC operation: MDA 3 Amp SLO-BLO Ceramic Time-Delay fuse
Mains Fuse 220-240VAC operation: MDA 2 Amp SLO-BLO Ceramic Time-Delay fuse
B+ Fuse: MDA 400 mA SLO-BLO Ceramic Time-Delay fuse
Badge Illumination: Units produced before 3/2003 use 8V, 0.3A "Fuse-Lamp" 1/4" X 1 1/4" - Serial numbers after MAHI036 use LED illumination which probably won't burn out
Dimensions: 11" deep x 10" wide x 5" tall
Shipping weight each: 18 pounds