If you are changing the tuning machines on your guitar, building a guitar or otherwise rejuvenating an old instrument, then here are some items that I stock for such projects and decided to share...
These rosewood buttons, sold in sets of six, are a classy upgrade to any of the Der Jung sets, but they work best on the premium, 18:1 ratio sets such as the 101, 102, 103, 200 306 and 526 models. Counter-sinking of the screw head will be recommended for adding these buttons to the sets that fasten the buttons with phillips head screw.
These S4 rollers have a bearing on the tip that will be a great upgrade to any of Der Jung's sets. The bearing is 13/32 inches or 10.2mm - slightly larger than the standard 10mm hole. The rollers are sold in sets of 6 and come with 6 extra spring washers to compensate for variations or inconsistencies in plate thickness.
These replacement gears are sold individually for tuners that have experienced excessive ware or complete failure of their gear(s). Choose between 14:1 and 18:1 by counting the teeth on your original gear. Be sure to inspect the machine and headstock for conditions that could lead to more gear misalignment and failures.
Here is a 5mm hex socket for servicing the buttons that are fastened with the decorative, ball tips screw found on the DJ102, 103, 306 & 106. The performance and reliability of these tuners depends upon this screw being tight enough to maintain the position of the worm in relation to the gear. So buy it and keep it on hand.
I have tested some of these string for the manufacturer for the past two years and have been very impressed with the sound that they are acheiving with their proprietory bass string technology. Truly there are still new frontiers in the making of guitar strings and we can never take for granted how that influences the making of our guitars and our techniques in playing them. Paired with normal tension carbon trebles, these "Inspiro" strings deserve test drive on your guitar.
This is my "go-to" humidifier that I provide with all of my new guitars when shipping them to their new homes. Fill them with distilled water and the chrystals inside will retain moisture and humidify your instrument while in the case. Given that moisture molecules travel 1,400 miles per hour and are lighter than the air we breathe, it's best to just use a humidifier and not kid yourself into thinking your case is going to keep your guitar from equilibrating with an excessively dry climate.
Here is an affordable and effective clip-on tuner for your guitar that has a full color LCD display. Battery and directions are included.