Hagerman Technology Cornet2 User manual

HAGERMAN
T E C H N O L O G Y
Cornet2
Phonostage Kit Manual

Cornet2 Phonostage Kit Manual
2
Warnings
This product uses dangerous and potentially lethal voltages. Extreme care must be taken
while assembling this amplifier and should only be attempted by a skilled technician.
The instructions in this manual are a suggested guide only and no liability is assumed by
Hagerman Technology LLC.
Copyrights & Trademarks
©Copyright Hagerman Technology LLC 2004. All rights reserved. No part of this
document may be photocopied, reproduced, or translated to another language without the
prior written consent of Hagerman Technology LLC.
Disclaimer
The information contained in this document is subject to change without notice.
Hagerman Technology LLC shall not be liable for errors contained herein or for
consequential damages in connection with the furnishing, performance, or use of this
material. See Chapter 6 for warranty information.

Cornet2 Phonostage Kit Manual
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1 Before You Begin
Description
Congratulations! You have just purchased one of the highest performance-per-dollar
audiophile products available. The Cornet2 phonostage is intended to bring high-end
audio and construction quality into the hands of do-it-yourselfers. It is part of a line of
vacuum tube products based on a common chassis and circuit board architecture. The
design is optimized for both ease of assembly and sonic excellence.
The circuit topology features common cathode class-A gain stages with no feedback,
passive equalization, and cathode follower output buffers with constant current sink
loading. Vacuum tube rectification for high voltage provides a gentle turn-on without the
need for muting circuits. The moderate gain accommodates all moving magnet and high
output moving coil cartridges.
The Cornet2 half-kit consists of these instructions, a blank circuit board, and a 1:1 drill
guide. You must purchase the remaining components from a few other sources.
Electronics are available from DigiKey and Antique Electronic Supply; the chassis from
Lansing Instruments. You may also substitute parts from your own stock.
Features
• All vacuum-tube signal path
• Pure class-A amplifier stages
• No feedback
• Cathode follower low impedance outputs
• Vacuum tube B+ rectification
Tools
This is a kit product and construction should only be attempted by skilled electronic
technicians. Chassis metalworking is also required. You will need an array of shop tools
and a good soldering iron. If you are at all unsure of this, send it back!

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2 Parts to Buy
Kit
If you purchased a factory assembled Cornet2, skip to Chapter 5. The kit does not need
to be built as specified, part substitutions or upgrades can be made at your discretion. It
is recommended you read this entire manual before starting.
Modifications
Here are a few simple modifications and upgrades possible to customize your unit.
 Upgrade signal capacitors to “auricap” brand: Change C203 to AES #CAUD1-450.
Change C200, C206, and C208 to AES #CAU1-450.
 Upgrade to gold plated RCA jacks: Buy RCJ-35 from www.allelectronics.com.
Even better, use AES #S-H267W (white) and #S-H267R (red).
 Change chassis anodize color from clear to black: Use Lansing #B2H12-V01B.
Parts List
Parts should be ordered directly from www.digikey.com and www.tubesandmore.com
(AES), and www.lansing-enclosures.com. See lists on following pages.

Cornet2 Phonostage Kit Manual
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Component Qty DigiKey References
47uF 450V 5 493-1461-ND C103, C201, C207
10,000uF 10V 3 493-1275-ND C106, C209, C210
470uF 10V 2 493-1269-ND C205
0.1uF 50V 2 EF1104-ND C102, C211
1uF 400V 6 PF4105-ND C200, C206, C208
0.1uF 400V 2 PF4104-ND C203
47nF 630V 2 495-1331-ND C202
1nF 630V 2 495-4164-ND C204
0.01uF 2kV 2 490-4217-ND C100, C101
LED R/G 1 754-1235-ND D100
1N5821 4 1N5821DICT-ND D101, D102, D103, D104
Grommet 10* RP456-ND
Power Cord 1 Q120-ND
Heat Sink 8 HS372-ND
Feet 4 SJ5523-0-ND
Standoff #4x1” 10* 4806K-ND
Fuse 2 F2419-ND F100
Dome, LED 1 L30032-ND
Grounding Post 1 J587-ND
RCA-2 2 CP-1435-ND J200, J201
AC Input 1 CCM1647-ND
Fuse Holder 1 WK0011-ND
Terminal 30 1285K-ND
Crimp 30 A27804-ND
Switch, Mono 1 360-1791-ND S200
2N3906 2 2N3906FS-ND Q100, Q101
2SC3942 2 TIP50-ND Q200
220 1W 20 220W-1-ND R101, R102, R103, R201, R208,
R212, R214, R216, R217, R219
680 1W 5 680W-1-ND R104
910 1W 10 910W-1-ND R203, R210, R215, R218
1.8k 1W 5 1.8KW-1-ND R220, R221
3.3k 1W 5 3.3KW-1-ND R213
6.8k 1W 5 6.8KW-1-ND R100, R106, R108, R205
10k 1W 5 10KW-1-ND R105, R204, R211
47k 1W 5 47KW-1-ND R200
150k 1W 10 150KW-1-ND R202, R207, R209
330k 1W 5 330KW-1-ND R107, R206, R222
1.8 5W 1 1.8W-5-ND R223
* Minimum purchased quantity.

Cornet2 Phonostage Kit Manual
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Component Qty AES References
Socket, 8-pin 1 P-ST8-193G
Socket, 9-pin 3 P-ST9-214G
Transformer 1 P-T370BX T100
12AX7 2 12AX7 V200, V201
12AU7 1 12AU7 V202
5Y3GT 1 5Y3GT V100
Screw #10 1* P-H245
Nut #10 1* S-HHN1032
Washer #10 1* S-HLW10
Screw #4 3* S-HS440-14
Nut #4 2* S-HHN440
Lug 1* S-H112
Component Qty Lansing References
Chassis 1 B2H12-V01A

Cornet2 Phonostage Kit Manual
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3 Assembly
Chassis
The instructions below refer specifically to the Lansing Instruments’ enclosure.
Nevertheless, you can still use a low-cost classic “Hammond” style chassis. Follow these
step-by-step instructions to machine the chassis pieces. If you plan to use upgraded RCA
jacks, their mounting holes will not be the same as those specified on the drill guides;
they need to be lowered to prevent interference with the circuit board.
 Use a scissor to notch out the four alignment holes in the printed drill guide.
 Place the drill guide on top of a blank top cover; align so the mounting holes are
centered in the crosshairs. Use a metal punch (sharp nail) to mark the center of
each hole.
Drill guide placed on top cover.
 Cut out the front and rear panel drill guides using a straight edge and razor blade.

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 Carefully drill holes on top cover, front and rear panels. Large holes are best
done using punches, but a step-drill also works fine. A file may be needed to get
a clean rectangular cutout on the rear panel.
 Wash the top cover with dishsoap to remove fingerprints and grime.
Finished chassis pieces.
Circuit Board
Assemble in the following order, solder and clip leads before continuing.
 Solder sockets onto the backside of circuit board. Insure rotation of octal socket
is correct (see dimple).
 Add six standoffs to bottom of circuit board using #4 nuts.
 Add two grommets.
 Install quick release terminals (for transformer wiring).
 Install all resistors.
 Install diodes.
 Install the 2N3906 transistors.
 Install all capacitors.
 Install fuse holder.
 Install RCA jacks.
 Install mono switch (optional).
 Mount the 2SC3942 transistors to heat sinks using #4 hardware. Install.
 Install heat sink shields near RCA connectors and transformer wiring.

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 Install LED onto backside of circuit board. Keep leads as long as possible (about
one inch). Tab on side labeled “LED*”.
 Soak and brush assembly in 99% isopropyl alcohol to remove solder flux residue.
Blow dry.
Completed circuit board.
Integration
If built properly, everything should fit together like a glove.
 Install rubber grommets to top cover.
 Install LED window to top cover.
 Mount transformer to top cover using the #10 hardware with primary wires
towards outside.
 Mount circuit board assembly to top cover, routing transformer wires through
grommets.
 Cut length of transformer wires to 5 inches above circuit board. Save the scraps!
 Add crimp terminals to all of the transformer wires.
 Plug in the transformer wires to the terminals on the circuit board. Use the
silkscreened chart for proper voltage selection.

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 Add crimp terminals to both ends of scrap wires colored brown, blue, and
brown/yellow.
 Add crimp terminals to one end of scrap wires colored green and green/yellow.
 Solder both open ends of the green and green/yellow wires to the eyelet lug.
 Install the ground jack to rear panel with above eyelet lug secured under the nut.
 Install ac input connector.
 Connect the brown/yellow wire from the L terminal to a switch terminal. Connect
the brown wire to the other switch terminal. Connect the blue wire to the N
terminal, and the green/yellow wire to the E terminal.
Rear panel showing wiring.
 Connect L (brown), N (blue), and E (green) wires from rear panel to terminals on
circuit board.
 Secure rear panel to assembly using #4 screws on the RCA jacks.
 Add chassis side panels.
 Install front panel.
 Add fuse.
 Install vacuum tubes
 Add feet to bottom cover. Do not install until after testing.