Sugarmaple Black Buff User manual

Black Buff Amplifier
Users' Manual
Rev May 12/14
Mapletree Audio Design
Al Freundorfer
R. R. 1, Seeley's Bay, Ontario, Canada, K0H 2N0
[phone]
www.mapletreeaudio.com
[email protected]
© Copyright Al Freundorfer 2014
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Introduction
The Black Buff is designed as a stand-alone tube-output-buffer for CD players, DAC or any line level
device. The result is an improved tonal quality, relaxed open musical detail and imaging, reduced
listener's fatigue and enhanced 3D effect of better recordings.
The Mapletree Audio Design Black Buff Amplifier represents a high performance development of an
octal-based buffer amplifier that uses the 6SN7/5692 or 12SN7 and is based on the cathode follower
from the Mapletree Audio Line 2 and Ultra 4 pre-amplifiers. Premium components include metal film
resistors and polypropylene film capacitors.
Many people would like to have the tube sound in their home theater without buying and building an
expensive all tube system. This can be solved by adding three Black Buffs to the outputs of a
DVD/Home Theater player to bring its performance up to a tube level quality. Placing one Black Buff
on the front channel, one on the rear channels and a final unit on the center channel and sub output
(three Black Buffs total), turns your DVD/Home Theater player into a respectable sounding 6 channel
tube output with excellent sound.
Input/Output Connections
There are a single pair of inputs and a single pair of outputs. The input level can be adjusted with the
front mounted gain control (optional). In cases where no preamp is used, this can be used as a volume
control. The RCA jacks allow connection to a line-level stereo source while maintaining the connection
to the regular amplification system. The input impedance is 100 k which is compatible with all sourceΩ
output circuits. The RCA output jacks are also at the rear of the Black Buff and can handle loads as low
as 5K ohms.
The standard IEC line cord is attached to the receptacle on the rear panel of the Black Buff power
supply. It is compatible with a 115/230/240 volts for world wide compatibility. A 0.1A/250 V fuse
provides primary protection for the power supply. It is located under the IEC line inlet. Under normal
conditions, it should not be necessary to replace the fuse. If power fails to come on, you can check the
fuse and replace with a spare if necessary. If the fuse blows a second time, you should not try to operate
the unit. Contact Mapletree Audio Design for information regarding servicing. The power switches are
located on the front panel. The LED pilot light indicates the power on.
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2
Fuse Tray
Power Switch
AC Power
Input
Power Indicator LED
Right Channe
Input
Left Channe
Input
Left Channe
Output
Right Channe
Output
Heater Vo tage Switch
(6.3 VDC down and 12.6VDC up)
Volume Control
Min. Vo ume:
Fu Counter-C ockwise
Max. Vo ume:
Fu C ockwise

Controls
The signal level in both channels is controlled simultaneously by the Alps volume control on the front
panel of the Black Buff amplifier.
Tubes
A tube burn-in period of several hours may be needed to achieve the best sonic performance. Tube life
should be thousands of hours. Aging tubes may result in a reduced gain in one or both channels or an
increase in noise levels. Infrequently, a heater may burn out which is indicated by total loss of sound.
The Black Buff is supplied with 1 – 6SN7 or 12SN7 tube. Replacement tubes can be obtained from
several suppliers in the U. S. and Canada. 6SN7 types are currently manufactured and are also available
as new old stock (NOS). Some listeners enjoy trying different brands and variants of tubes. The
greatest sonic variation will occur with different driver tubes.
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Warranty
Factory assembled MAD components are warranted for 2 years to the original purchaser for failure of all parts (excluding tubes).
Tubes are warranted for 90 days exclusive of shipping cost. Service, including parts and labor (but excluding shipping), is free within
the warranty period.
Additional Notes
This manual is an aid to the user for the operation of the Black Buff. Details of the amplifier and power supply circuits are
subject to change without notice so as to achieve the best possible performance. The schematic is only representative of the
actual amplifier and component manufactures, model and values may vary.
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Front
Back
6SN7 or 5692/12SN7

MAD Black Buff Specifications
Frequency response at 0.2 Vrms output into 4.5k, 10k and 25k Ohms load:
10 100 1000 10000 100000
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
Frequency [Hz]
Relative Gain [dB]
5Vrms output at 1 kHz: 4.5K Ohm load 0.5% THD predominately 2nd order distortion.
Output impedance at 1 kHz: 454 Ω
Input impedance: 100 kΩ
Hum and noise at output: less than 0.1m Vrms
Phase: non-inverting
Power consumption: 4 W, 120 VAC (230 and 240 VAC) 50-60 Hz
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Vout=5.0 Vrms
4.5K Ohm Load
10 K Ohm Load
25 K Ohm Load

MAD Black Buff Head hone Am lifier
Version:1
© Copyright A P Freundorfer 2014
Rev. Apri 2014
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