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Manley Laboratories

Manley Neo Classic 300B Preamplifier

Manley Neo Classic 300B Preamplifier

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Regular price $7,999 In stock now!
Regular price $7,999 Sale price $7,999 In stock now!
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The Neo-Classic 300B preamplifier is the first and only preamp to feature the classic directly heated 300B Triodes. Manley Labs been designing the 300B into small power amps for many years and always had great respect for the smooth natural sound of this tube. However, a single 300B provides truly appropriate power and voltage swing for headphones and makes a remarkable line driver. Here is where the impedances are not too low and the power requirements are not too high: ideal for this kind of tube in a single-ended configuration. This was the genesis of a new preamp.

Manley Labs combines the historic 300B with another classic, the large octal based 6SL7GT, for the input stage - all triodes running in pure Class A operation. To complement this 'retro' feel, vacuum tube rectification and regulation in the power supply along with plenty of capacity are employed. An additional (and innovative) ripple rejection circuit is then added to filter out power supply noise making this an incredibly low-noise preamplifier - especially critical for headphone users.

Complementing this lovely and rich sounding line-driver is a motorised ALPS audiophile volume control, gold plated RCA connectors, high purity silver wire, mil-spec printed circuit boards with extra thick copper and plating, and custom designed output transformers which we wind right here in our own magnetics department. It all adds up...

Call Upscale Audio today at 909-931-9686. We're happy to take your call and answer any questions you may have.



  • Inputs: 5 stereo pair unbalanced RCA jacks
  • Outputs: 2 stereo pairs MAIN out same as SUB out unbalanced RCA jacks
  • RECORD output: 1 stereo pair pre-volume control unbalanced RCA jacks
  • HEADPHONE Outs: 2 front panel 1/4" headphone jacks
  • Optimized headphone impedance switching: 30-400 ohms to 300-4000 ohms
  • MUTE: Selecting HEADPHONE operation mutes LlNE outputs
  • Output Vacuum Tubes: 2 x 300B
  • Input Tubes: 2 x 6SL7GT
  • Rectifier Tubes: 2 x 5U4G or 5AR4
  • Regulator Tubes: 2 x OD3
  • Gain: 12 dB
  • Internal Variable Feedback: 8.5 dB of global NFB is used @ 12 dB of gain, adjustable trim -1.7dB to +1dB
  • Noise Floor: typically -70 dB (1 Hz - 100 KHz)
  • S/N Ratio: typically 105 dB (A WGT, 20 Hz - 20 KHz)
  • Frequency Response: 5 Hz to 50 KHz ±1dB
  • THD: 0.08 % @ 1KHz at 1V rms out
  • Distortion THD+N: -80 dB (.01 %) zero "crossover" distortion, mostly 2nd harmonic
  • Input Sensitivity: 250mV (-9.8dBu) yields 1V out
  • Input Impedance: 100 Kohm Noble volume control
  • Maximum Input Level: 5.5dBu or 1.459 Vrms @ 1KHz, volume control at maximum
  • Output Impedance (LINE STAGE): 100 ohms
  • Maximum Output Level: 17.2dBu or 5.636 Vrms @ 1KHz, volume control at maximum
  • Output Power (100 ohm Headphones): 1W (10 V RMS) (28 V P-P)
  • Output Power (600 ohm Headphones): 1W( 25 V RMS) (70 V P-P)
  • REMORA REMOTE: controls motorised volume control UP/Down; uses 9V battery
  • Power Consumption: 170 Watts (1.4 A @ 120VAC)
  • Operating Mains Voltage: Factory set for 100V, 120V or 220-240VAC operation for original destination country's mains voltage.
  • Mains Voltage Frequency: 50~ 60Hz
  • Dimensions: W=19" x L=13" x H=11"
  • Shipping Weight: 28 Ibs.