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. 

 

Click on tubes for more information!


   
July News and Specials


•  VACUUM TUBE VALLEY magazine: complete set of issues 1 to 20. Excellent condition, stored in binder. $250 USD incl. shipping to N. American locations.

•  Demo Ear+ HD available for immediate shipment. $650 with free shipping to N. America. Only a few hours running time on this red and black unit in mint condition.





Mapletree Audio Design Product Overview
Go to:   Preamps  •  Headphone Amps  • Power amps  •  Other products

NOTE: All MAD components, with the exception of the Super Stealth and Stealth Max power amplifiers, are available for 230-240 VAC 50 Hz at no extra cost. Super Stealth and Stealth Max monoblocs for 230-240 VAC are available at a slightly higher price.  

Chassis colors include RCA red, textured black, Sylvania yellow, eggshell white, cobalt blue, and sage green. Solid maple side panels are finished in ebonized black or natural.



Preamplifiers




Line 2A SE Line Preamplifier (kit and assmebled)

Review of Line 2A SE by John Hoffman in Affordable Audio July/07 issue
Review of Line 2 by Chris Thompson on
Head-Fi

• Line 2A SE Preamp wins "Affordable$$Audio 2007 Big Bang, Little Bucks Award". See the January Issue of Affordable$$Audio (www.affordableaudio.org).

Premium passive components include Auricap coupling capacitors.
• Optimized circuitry for lowest distortion and noise.
• 3 inputs, 2 outputs, volume and individual channel level controls.
• 2 x 12SN7GT with switch for 6SN7GT tubes.
• Separate PS 2 power supply (with 6X5GT tube/HEXFRED hybrid rectification) included.
  More Information  •  Customer Comments




Ultra 4A SE Phono/Line Preamplifier

"MAD [Ultra 4] is my vote for best bang for the buck, heck maybe even best product contention at any reasonable price". 

NEW! Customer Review of Ultra 4A and Ear+ Purist 
Reviewof Ultra 4A  by Pat McDemott on Audio Asylum
Review of Ultra 4A SE by JR Cody on audioweb.com
Reviewof Ultra 4A by Scott Faller (TNT-Audio
Reviewof the Ultra 4 by Tom Mitchell on AudioCircle



• Premium passive components include Auricap coupling capacitors
and Black Gate bypass capacitors.
• 48 dB phono gain, two 18 dB line inputs, two line outputs.
• Individual channel level controls plus volume control for optimum gain adjustment.
• 2 x 12SN7GT (switchable for 6SN7GT) and 2 x 12SC7.
• Separate PS 2 power supply included.
(Shown in custom grey hammertone finish)

More Information  •   Customer Comments





PS 2  Power Supply (included with Line 2A SE (kit and assembled) and Ultra 4A SE) 

•  Provides 12 VDC@1A (regulated) and +200 VDC@15 mA.
•  Power cable and detachable IEC line cord included. 
•  Employs high-speed diodes with 6X5GT rectifier tube in hybrid bridge.
•  Soft startup relieves stress on tubes and filter capacitors.
More information



Headphone Amplifiers



"Now I have to listen to all my CDs all over again. I have a decent stereo system but with the Ear+ it sounds like a $20,000 setup".

Review of the Ear+ by Steve Albers on Audio Asylum
Review of the Ear+ by Nicholas Schell on Head-Fi
Comments on Audiogon
Designing the Ear+ by Lloyd Peppard
User Comments
 



Ear+ HD High Definition Headphone Amplifier (kit and assembled)


• Outstanding headphone performance for a wide range of headphone impedances and drive requirements.
• 2 x 12B4A NOS and 1 x 5751/12AX7/ECC83 tubes.
• High and low impedance headhone jacks.
• Premium passive components include Tantalum film plate resistors and Black Gate capacitors in signal path.
• Ultra high-speed rectifier diodes and Alps volume control are standard.
• Passive line output for use as a passive preamp.
• Dual inputs for easy patching into system.
  More Information   •  Customer Comments


Ear+ HD Super Headphone Amplifier (assembled only)

Based on experience with the high-voltage power supply of the HD200 Special Edition, the new HD Super offers increased  power output plus the benefits of soft-start tube rectification.  It will drive two or more sets of headphones simultaneously. Other specs and features are the same as the Ear+ HD including dual inputs and passive output. A Black Gate filter capacitor for the driver stage plate supply is standard. Options include an all-Black Gate power supply ($60), locking Neutrik headphones jacks ($30), and a DACT stepped attenuator ($230). Chassis is 12" x 8" with rock maple side panels.


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).


               

                     
Download the User's Manual for detailed information.

Super Stealth monobloc power amplifier (kit and assembled). Using the new 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. Available as a kit or factory assembled.
• 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.
More Information
Super Stealth kit manual









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. 

More Information
Installation Manual


Other Products

 

 The "Thingy" crossover and multi-channel driver.






Based on the concepts described in the Branches newsletter issue 4 , the MAD Thingy is in production. It features buffered high and low pass filters to implement a 500 Hz high-level crossover for driving multiple speaker systems or bi-amp aplications, plus  outputs for ambience and subwoofer channels. For more details, you can download the user's manual.

User comments.







Eyes for your Ears! The Viper Magic Eye Monitor. Left and right channel levels are displayed by two 6E5C cathode ray tubes. Includes response speed and sensitivity controls with built in 12SC7 voltage amplifier stage.
More information.

New! Viper 4+ deluxe magic eye monitor and line router. Separate peak and average eye tubes for each channel with individual sensitivity controls. Internal voltage amplifier allows monitoring signals from line level sources, preamp outputs, or power amp outputs. Includes a 3-input, 3-output line router with selected input signal monitored. Router functions without power applied. Dimensions 12"  x 8". With 1629 cathode ray indicator tubes priced at $750 ($700 with Russian 6E5C tubes). Available for 240 VAC at no extra cost!

Download the User's Manual for detailed information.


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.
LR 1 Pro model features 3–2 switching with balanced I/O and XLR connectors.





Dr. P spins some 78s on his mini system. Photo by Christian Keresztes
For more information or to place an order, please telephone or email Lloyd Peppard at
(613) 387-3830
info@mapletreeaudio.com

Lloyd Peppard
Mapletree Audio Design
158 Seabrooke Rd
R.R. 1, Seeley's Bay, Ontario, Canada K0H 2N0

Credit card payments through PayPal are highly recommended. Registered PayPal email address is lloyd.peppard@sympatico.ca.