Vacuum Tube Sound for the 21st CenturyMapletree 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 these tubes for more information!
Other Products (line routers,
Dynaco driver boards, power amplifiers, crossovers)
Customer Photo of the Month:
John Healey: Custom Ear+ HD Super II with Grado RS1i.
HD300 Commemorative Limited Edition
Two limited edition HD300 headphone amplifiers are being produced to commemorate reaching the 300th production Ear+ headphone amplifier. They feature an all-octal tube lineup with EF37A (6J7) pentode drivers and a 6AS7G output. Now available for order with a 2-week lead time. Price, including shipping to N. America, is $1100. Only 1 left!
View measurement-based specifications.
HD300 Limited Edition with Mullard NOS EF37A drivers and GE NOS 6AS7G output, toroid power transformers, gold plated sockets, Panasonic polypropylene output capacitors, Philips carbon film resistors, with ebonized walnut and purpleheart trim.
NEW PRODUCT LINE: SugarMaple
Over the next year or so, Mapletree Audio Design Associate, Dr. Al Freundorfer, will be offering new designs and innovative re-working of existing Mapletree products under the SugarMaple banner. The first new product is the OD300 (Octal Duo) Headphone Amplifier. It uses the same output tube as the HD300 above (6080, special 6AS7G) but with a 6SL7 triode driver stage. Polypropylene output caps are standard and circuit adjustments ensure a flat frequency response form 20 Hz to 20000 kHz. The high output power and low driving impedance of the 6080 easily handles any headphone sensitivity and impedance characteristic. As an introductory special, the SugarMaple OD300 with power supply is priced at $900 with free shipping to N. America for the month of November. For more details and complete spcifications, you can download the User's Manual.
Alternate corner design is available as shown below.
|Mapletree Audio Design Product Overview|
Headphone Amps Other products (Power amps,
Dynaco ST70 driver module, Magic Eye monitors, Line
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. Side panels are available in stained oak or ebonized maple (see Ear+ HD photos below for examples).
SE Line Preamplifier
Line 2A SE Preamp wins "Affordable$$Audio 2007 Big Bang, Little Bucks Award". See the January Issue of Affordable$$Audio (www.affordableaudio.org).
Also availableLine 2B HT
with Home Theater bypass. The source input switch is
modified to select Line1, Line2, or HT. In HT mode, Line2
(front channels) is routed to the output completely isolated
from the preamp
circuitry (preamp can be powered off).
NEW! Alternative styling for Line 2B/PS 2/Ultra 4B/LR 1. If wood side panels aren't your first choice, consider an anodized aluminum front panel as shown her for a Line 2B/PS 2. Black chassis only.
L2X Line Preamplifier with PSX Power Supply.
For those who appreciate the concept of the "most bang for the buck", I am pleased to introduce the Mapletree L2X preamplifier with PSX power supply. The amplifier circuit of the L2X is identical to that of the highly respected Line 2A SE. In the preamp itself, the differences are in some of the components used (Alpha carbon potentiometer instead of Alps, Nichicon polypropylene film caps instead of Auricaps) and in some simplifications in the physical layout and appearance. There are two inputs with a selector switch located on the rear panel. The compact PSX power supply employs solid state rectification (with high speed diodes) and a dc heater supply. The basic specs for the L2X are identical to those of the Line 2A/B SE. The price for the preamp + power supply is $600 plus shipping.
Ultra 4B 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
Ultra 4B SE features:
Premium passive components include Auricap XO polypropylene film coupling capacitors and Alps volume control..
48 dB phono gain, two 18 dB line inputs, two line outputs.
Volume and Balance controls.
2 x 12SN7GT (switchable for 6SN7GT) and 2 x 12SC7.
Separate PS 2 power supply included.
(Shown in sage green finish)
PS 2 Power Supply features:
Outputs of 12 VDC@1A (regulated) and +200 VDC@15 mA.
Power cable and detachable IEC line cord.
High-speed diodes with 6X5GT rectifier tube in hybrid bridge rectifier (Soft startup relieves stress on tubes and filter capacitors).
More Information Customer Comments
"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".
Ear+ HD Super II Headphone Amplifier.
The use of 6BQ5/EL84 output tubes in the Ear+ HD250 was popular with customers who appreciated the wide availability of the type. Like the HD250, the new HD Super II utilizes the EL84 with triode connection in cathode follower mode (as is the 12B4A in the Ear+ HD). The 12AX7/5751 drivers are configured in SRPP topology. The power supply is constructed on a separate chassis to obtain the lowest possible noise floor and to minimize heat buildup in the main amplifier chassis, thus increasing component life expectancy. Both units are a compact 5" wide. Appearance is distinctive with brushed aluminum and chrome trim. Wood side panels are not available as both chassis have ventilation holes along the sides. The two chassis can be stacked, positioned side by side or even located on different shelves. A 1 ft power interconnect cable is supplied; longer cables can be requested. Available with 240 VAC wiring at no extra cost.
User's Manual with full specifications
Passive preamp option provides three inputs and a passive output.
Now Available: Remote volume control module for HD Super II.
Bent Audio motorized Alps potentiometer or DACT stepped attenuator options.
Provides 4 inputs, source output, and passive preamp output. Please inquire about price and package options.
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 Audio Note Tantalum film plate resistors and Alps volume control.
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
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