JFT Assembly Guide

For recommended tools and safety precautions, refer to the Colour Pallet Assembly Guide.
Identify and Sort Components
Before you begin stuffing the board, it's a good idea to sort the components using the JFT Component Sorting Sheet (PDF). Note that the actual value of R5 is 820, not 680 as marked on the PCB.
1. Stand Offs and Connector
Begin by snapping in the white nylon standoffs. Make sure you are inserting the the flat side into the Colour PCB. You should feel it snap in. Note that the other side is more rounded, which goes into the Pallet Motherboard for easy inserting and removing. In order to keep the connector in place and level, snap in the stand offs before soldering.
2. Solder Connector
Solder the 8-pin connector with the short leads facing up.
3. Insert and Bend Resistor Leads
Bend the resistors and put them into the spaces shown on the PCB legend. Flip the PCB over and bend them against the PCB to keep them in place for easy soldering.
Note: As indicated in the component sorting sheet, R5's actual value is 820, not 680 as marked on the PCB.
4. Solder Resistors
Make sure to keep your tip clean and apply a small amount of solder while placing the tip where the bent lead meets the pad.
5. Trim Resistor Leads
Let the freshly soldered resistors sit for a few seconds to cool completely. Then trim the excess leads at the tip of the solder joints.
6. Capacitors, Transistor and IC Socket
Note that the first revision of PCBs contains an error on the PCB legend: C1's actual value should be .1uF instead of 10uF. Repeat the same process as the resistors for the capacitors. Once all they are bent and held into place, insert the 8-pin IC socket into position, making sure to align the notch in the plastic with the notch on the PCB. Optionally, tape the socket to the PCB to keep it in place when you flip the board for soldering. Insert the transistor with the flat side facing the same way as noted on the PCB and bend the leads. Solder then trim the leads of the capacitors, socket, and transistor. Note: Due to a momentary lapse of reason, we did not install RLED during the making of this guide. That's a mistake. You should install it with all the other resistors.
7. Trim Potentiometers
Note that, although they look almost identical, there are two different values of trim pots. VR1 is marked "301" and VR2 is marked "103."
8. Electrolytic Capacitor
Insert the tall, electrolytic capacitor. This capacitor is non-polarized, so there is no correct orientation for it on the board. Bend, solder, and trim the leads. And that's all for the assembly!
9. Insert IC
Insert the IC into the socket. The TL071 IC's orientation is indicated by a circle next to pin one. Insert the IC with the circle facing the notch in the socket and PCB legend.
10. Distortion and Gain Adjustments
Don't Panic: The steps below require you to adjust a component on the JFT board while the circuit is powered up and working. If you accidentally touch the wrong components with the screw driver, it may damage your JFT, Palette, or even 500-series rack. Take a deep breath, keep a steady hand, and enjoy the experience. This is real DIY, my friend!
No two of the transistors used in the JFT are exactly alike. So to make them behave the way we want, we've got to adjust their surrounding environment a bit. This requires a screw driver, audio interface, and the most sophisticated test equipment known to humankind: your ears. Plug your assembled JFT into your assembled and tested Palette, turn it on, and connect it to your mixing setup so that you can send signals to your Colour and monitor its output. Send some typical program material to your Colour channel--acoustic guitar and piano tracks work well, but you will surely want to try various sources--with the nominal level set to +4dBu. For most professional audio equipment, this is the standard line output level. So, for most interfaces, simply assign the track to the output your Colour is plugged into and set the track's fader at its default level. If your interface includes a volume control for the line outputs, set the control to unity gain, sometimes marked as "line." Now play with the front panel controls and the JFT's distortion trim until it sounds like the tool you want it to be. That's right, what we're going for here is to set the JFT trim where the unit is most useful and inspiring to you for a range of program materials and Saturation settings. Your ears will make the final decision, but here are some general guidelines:
  • With Saturation turned all the way down, distortion should be practically unnoticeable.
  • With Saturation turned all the way up, distortion should be clearly audible, if not crunchy and agressive.
  • With Saturation set to the gap between the two bars on the front panel legend, distortion should register as an "enhancement" of the original signal. That is, it it heard as "warmth" or "color" rather than distortion.
You will most likely need to go back and forth between the gain and distortion trimmers several times before finding the sweet spot. For the final gain trim, turn the Saturation down all the way and push the JFT bypass/engage switch every few seconds. Adjust the trim until you do not hear a difference in volume between having the JFT engaged and bypassed.
That's it! Congratulations on adding another colour to your Palette. If your JFT isn't working, please submit a support request and we will work with you until it is:

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If you have any corrections, additions, or suggestions for this build guide, please let us know with a comment below.