Related Manuals for AkitikA PAT-4
Summary of Contents for AkitikA PAT-4
- Page 1 PAT-4 PHONO PREAMP REPLACEMENT (PAT4PPR) ASSEMBLY MANUAL © 2017 AkitikA, LLC All rights reserved Revision 1p08 January 25, 2017 Page 1 of 24...
-
Page 2: Table Of Contents
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 Reminders ................... 16 Gain Tweaks ......................... 17 More Tweaks ........................ - Page 3 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 .............. 24 Page 3 of 24...
-
Page 4: Section 1: About This Manual
The PAT4PPR is installed much farther from the power supply, so picks up much less of the stray hum fields inside the PAT-4. This makes it very quiet and free of hum. The only hum you will pick up comes from the phono cables outside of the PAT-4. -
Page 5: Recommended Solder
5. Reassembling the preamp. Important Safety Notes By purchasing, using, or assembling this kit, you have agreed to hold AkitikA, LLC harmless for any injuries you may receive in its assembly and/or use. To prevent injuries: Wear safety glasses when soldering to prevent eye injuries. -
Page 6: Section 2: About The Phono Preamp Upgrade
The preamp won’t clunk when you switch it in and out of the phono position. Your cartridge will see the correct 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. -
Page 7: Component Order
Begin by carefully emptying the contents of the parts envelope into a broad soup bowl, as shown below. In general, you’ll start with the components that lay closest to the board, working your way towards the taller components. You will: 1. - Page 8 resistor with the fat brown band on the right, then you can read both the Color Code column and the resistor from left to right. Here are two assembly hints: 1. Finding the components: The PC Board has two essentially identical layouts, one for each channel: a.
- Page 9 Now you’ll install the non-polarized capacitors. We start with the smallest capacitors, and work toward the larger capacitor values. These capacitors are not orientation sensitive. Desig Value Marking Done☑ 100 pF 101, axial □ 100 pF 101, axial □ 220 pF 221, axial □...
-
Page 10: Prepare And Add Shielded Cables To The Inputs
Prepare and Add Shielded Cables to the Inputs For lowest hum, you must use shielded cable between the PHONO LOW RCA Jacks and the inputs on the PCB. Prepare two 4” lengths of shielded cable: 1. One for the right channel, using the red conductor and the drain wire. 2. -
Page 11: Preparing To Install The Assembled Pat4Ppr Circuit Board
Drilling Mounting Holes in the PAT-4 Chassis You’ll need to add two 9/64” mounting holes to the PAT-4 chassis. 5/32” holes are also ok, and may give you a bit more margin if you drill slips a bit. It’s a good idea to use a center-punch to locate the centers of the two mounting holes. -
Page 12: Move Power Wires
Make the following connections between the shielded cables and the RCA jacks: 1. Right channel signal conductor (red) to center of right channel RCA jack. 2. Right channel ground conductor (drain wire covered with a bit of reserved gray jacket insulation) to the ground lug of the right channel RCA jack. 3. -
Page 13: Move Selector Switch Wires
1. Identify the wire that connects to terminal 8 of the front deck of the selector switch. De-solder the opposite end of that wire from its current location. a. If your PAT-4 phono section was stock, that end was connected to the center terminal of the right channel PHONO LOW RCA jack. -
Page 14: Converting To Accept 5 High Level Inputs And 1 Phono Input
Converting to Accept 5 high level inputs and 1 phono input These modifications will give you 5 high level inputs and 1 phono input. After performing these modifications, TAPE HEAD and SPECIAL will both accept normal high level inputs. Ground Changes, refer to Figure 9. Done ... -
Page 15: Figure 9-Back Panel Re-Wiring
Figure 9-Back Panel Re-wiring Page 15 of 24... -
Page 16: Inspection And Preliminary Reassembly
PCB will slide in there nicely. Final Sanity Checks Here are a few last tests before you reconnect your PAT-4 to your music system. With the top still off, plug in the AC mains. Turn on the power switch. Set your meter to DC volts. -
Page 17: Gain Tweaks
I think you’ll find that the phono preamp has just the right amount of gain for you, which will put the PAT-4 volume control at a nice play when you play LP’s. However, if you find that the phono preamp has too much gain for your setup (cartridge and power-amp), you can drop it by up to 6 dB by increasing the value of both R4 and R17 to 300 Ohms. -
Page 18: Schematics
Schematics Figure 10-Phono Preamp Schematic Page 1 Page 18 of 24... -
Page 19: Figure 11-Phono Preamp Schematic
Figure 11-Phono Preamp Schematic Page 2 Page 19 of 24... -
Page 20: Specifications
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) ... -
Page 21: Appendix 1: The Toothpick Trick
Appendix 1: The Toothpick Trick This appendix describes an easy way to clear the solder from a hole in the PCB. It can also be used to clear the solder from terminals on pots or jacks. Doing so makes it easier to install a new component, or reinstall wires that were temporarily removed to allow access to some other component. -
Page 22: Appendix 2 - Preparing A Shielded Cable End
Appendix 2 - Preparing a Shielded Cable End This section tells how to prepare the ends of the shielded cable. This process will be repeated four times, at both ends of both input cables (although the cables will have different overall lengths). 1. -
Page 23: Figure 12- Shield Wire End Prep Completed (Right Channel)
5. Separate and twist the drain wire. 6. Peel back and remove the foil. Remove the plastic wrap from the red and black wires. The drain (bare wire), red, and black wires are exposed now that gray insulating jacket, foil shield, and plastic over-wrap have been removed. 7. -
Page 24: Appendix 3 - Resistor Color Code
Appendix 3 - Resistor Color Code Figure 13-demonstrating the resistor color code Here’s an extreme close-up of a ¼ W metal film 20K (20,000) Ohm resistor, designated by the standard resistor color code. The colors map to numbers: Color Number Black Brown Orange...
Need help?
Do you have a question about the PAT-4 and is the answer not in the manual?
Questions and answers