Vacuum Tube Sound for the 21st Century

Mapletree Audio Design offers a unique range of products designed and hand crafted by Dr. Lloyd Peppard, a retired electronics engineering professor. The goal is to increase your enjoyment of recorded music through the use of vacuum tube amplification and signal processing. 

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Other Products (download User's Manuals from home page or contact Mapletree Audio for more information)

Power Amplifiers

Stealth Max Monobloc Power Amplifier - 50 W with KT88s running class AB1 ultra-linear with fixed bias. Triode mode switch. Built on a stainless steel Dynaco Mk III chassis  with Mullard  topology driver circuitry (6SJ7 voltage amplifier and 6SN7GT long-tail phase inverter) and Dynaco spec output and power transformers. WIth premium passive components and a very stiff power supply, the sonics are effortless and open, espeicially noticable on high level transients. Available for 240 VAC ( $30 additional).



Super Stealth monobloc power amplifier. Using the EH 6V6GT tubes in class AB ultra-linear push-pull, the Super Stealth delivers a clean 8 W, making it suitable for a wide range of speaker systems.
• 20-20 kHz -1 dB at 5W
• Mullard topology driver circuitry using 12SJ7 pentode and 12SC7 cathode-coupled phase inverter.
• Supplied with EH 6V6GT matched pair output tubes.
• Quiet, ultra high speed diode power supply and DC heater supply for all tubes.
• Ultra-low output noise–less than 025 mV (90 dB below rated output) makes it suitable for high-efficiency speaker systems.
• Input level control for optimum sensitivity adjustment; input sensitivity 0.5 V.
• Compact chassis 7" x 12" x 6" overall.

Super Stealth SE
monobloc power amplifier
. The special edition of the Super Stealth includes provision for 12 V or 6 V driver tubes, dc balance adjustment for output tubes, and bias adjustment.

Special Red octal driver module for Dynaco Stereo 70 power amplifiers. A drop in, point-to-pointwired driver board using Mullard driver topology with 2-6SJ7 and 2-6SL7GT tubes. 

Line and Speaker Routers

LR 1 Line Router

• Any combination of 6 or less I/O lines is possible. Design it yourself to suit your needs.
• Ideal for switching line sources between headphone amplifier or preamp or adding additional line inputs to preamp.
• Appearance as shown for LR 1 Pro below.

LR 1 Pro Balanced Line Router

• Any combination of up to 3 inputs and/or outputs.
• Neutrik XLR connectors.

SP 1 Speaker/Amplifier Router

• Two power amplifiers to one speaker system or one amplifier to two speaker systems.
• Bi-directional (either configuration can be used in reverse direction if needed).
ETO (Engineered To Order): Expanded I/O capability can be provided . Prices available on request.