AkitikA PAT-4 Скачать руководство пользователя страница 20

Page 20 of 24 

Specifications 

Frequency response – typically within a 0.5 dB error band between 20 Hz and 20 kHz, 
with the exception that the response is -0.5 dB at 20 Hz in support of the high pass filter. 

 

High Pass Filter (with respect to 1 kHz) 

 

-0.7 dB at 20 Hz 

 

-7.4 dB at 10 Hz 

 

-19 dB at 5 Hz 

 
Low Pass Filter (with respect to 1 kHz) 

 

-0.5 dB at 20 kHz 

 

-4.4 dB at 100 kHz 

 

-10 dB at 500 kHz 

 

-22 dB at 1 MHz 

 
Gain at 1 kHz – 33.4 dB 
 
Distortion 

 

5 mV rms input at 1 kHz produces 230 mV RMS with only 2nd harmonic, which 
is -87 dB (0.0044% distortion) 

 

10 mV rms input at 1 kHz produces 460 mV RMS with only 2nd harmonic, which 
is -80 dB (0.01% distortion) 

 

40 mV rms input at 1 kHz produces 1.84 Volts RMS with just 0.044% distortion. 
40 mV is probably 4 times as much as will ever come out of your phono cartridge. 

Содержание PAT-4

Страница 1: ...Page 1 of 24 PAT 4 PHONO PREAMP REPLACEMENT PAT4PPR ASSEMBLY MANUAL 2017 AkitikA LLC All rights reserved Revision 1p08 January 25 2017...

Страница 2: ...Converting to Accept 5 high level inputs and 1 phono input 14 Inspection and Preliminary Reassembly 16 Final Sanity Checks 16 Prepare to Reconnect your PAT 4 to your Music System 16 Record Playing Rem...

Страница 3: ...3 of 24 Figure 10 Phono Preamp Schematic Page 1 18 Figure 11 Phono Preamp Schematic Page 2 19 Figure 12 Shield wire end prep completed right channel 23 Figure 13 demonstrating the resistor color code...

Страница 4: ...nd order lowpass filter that makes it much less likely to pick up external signals like switching transients and radio stations The PAT4PPR is installed much farther from the power supply so picks up...

Страница 5: ...the phono preamp section of the original preamp circuit boards to the new phono preamp 4 Fastening the new phono preamp in place and performing a few sanity checks 5 Reassembling the preamp Important...

Страница 6: ...rrect loading impedance The original PAT 4 design used a form of feedback biasing that made its input impedance look inductive falling to 10K ohms or less at low frequencies This kit presents an input...

Страница 7: ...e Resistors In general you install the resistors by placing the body on silk screen side of the board and the leads through the indicated holes Bend the leads over on the back of the board to keep the...

Страница 8: ...e Marking Done R4 158 Brown green white black brown R17 158 Brown green white black brown R2 1k Brown black black brown brown R3 1k Brown black black brown brown R10 1k Brown black black brown brown R...

Страница 9: ...3 C22 3 3 F 3 3k63 The following capacitors are electrolytic capacitors The polarity is important Be sure to look at the polarity as marked on the silk screen and make it agree with the capacitor mark...

Страница 10: ...lete installation of the input wiring Figure 3 Shielded cable installation right channel shown here Connect the wires as follows 1 Right channel signal wire red to the eyelet labeled INRIGHT 2 Right c...

Страница 11: ...ift off the mark Figure 5 Locating the mounting holes Locate the drill holes near the selector switch as follows 1 The front mounting hole should be on a line with the front hole that holds the cover...

Страница 12: ...pictured Figure 7 Connecting Left Channel input jack and 0 01 F capacitor Move Power Wires At this point 17 5 V 17 5 Volt power and ground wires run from the PAT4PWR board to the phono section of the...

Страница 13: ...onnected to eyelet 5 of the front preamp PCB 2 Re attach the end of that wire to the OUTRIGHT eyelet of the new PCB Cut it to a reasonable length Insert the wire from the solder side and solder it on...

Страница 14: ...s refer to Figure 8 Done Identify the wire that connects to terminal 5F of the front deck of the selector switch De solder its far end it will typically be connected to eyelet 1 of the front PC 16 Ide...

Страница 15: ...Page 15 of 24 Figure 9 Back Panel Re wiring...

Страница 16: ...f the new phono preamp should measure between 17 and 18 Volts DC with respect to ground The voltage on eyelet 12 of both original preamp PCB s should measure between 36 and 40 volts DC with respect to...

Страница 17: ...d the cartridge body in one hand o Rotate the push on connectors around the input pin using needle nose pliers This will clean the crud and also let you tell if the connections are so loose as to also...

Страница 18: ...Page 18 of 24 Schematics Figure 10 Phono Preamp Schematic Page 1...

Страница 19: ...Page 19 of 24 Figure 11 Phono Preamp Schematic Page 2...

Страница 20: ...Pass Filter with respect to 1 kHz 0 5 dB at 20 kHz 4 4 dB at 100 kHz 10 dB at 500 kHz 22 dB at 1 MHz Gain at 1 kHz 33 4 dB Distortion 5 mV rms input at 1 kHz produces 230 mV RMS with only 2nd harmoni...

Страница 21: ...of the hole that you re trying to clear Heat the solder land on the component side of the board until the solder flows Insert the toothpick from the component side of the board while pushing and twis...

Страница 22: ...le 3 4 back from the end Hold the blade perpendicular to the cable and draw it across the cable lightly as you rotate the cable along its long dimension This creates a scored line through the plastic...

Страница 23: ...ed wire for RIGHT channel signals 8 To make a shielded cable for a LEFT channel application pull the red wire out of the shielded cable and leave the black wire for LEFT channel signals 9 Remove 1 4 o...

Страница 24: ...bers Color Number Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Gray 8 White 9 The color band positions have the following meaning Position Meaning 1 Left most Digit e g most signifi...

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