Few pickups have seen the kind of resurgence that the Filter’Tron has experienced recently. In the past, the Filter’Tron was championed only by staunch Gretsch devotees. But today, many guitar and pickup manufacturers are utilizing the Filter’Tron’s unique sound and look more often.
When Fender took over operations at Gretsch in 2003, the beloved pickup made its way out of traditional hollow-bodied guitars and into all manner of Telecasters (such as the popular Cabronita models), Stratocasters, boutique builds, and brand new Gretsch models.
Pickup maker TV Jones brought new life to the pickup and, soon after, Seymour Duncan and Lollar were producing their own flavors of the classic Gretsch sound as well.
History
According to Chet Atkins’s 2001 autobiography, Chet Atkins: Me and My Guitars, it was his friend and inventor Ray Butts who devised the Filter’Tron to combat the 60 cycle hum inherent in early single coil pickups.
Gretsch was utilizing DeArmond pickups at the time. Chet was constantly battling the hum as his popularity and volume increased. Butts wired two coils out of phase, creating what could be considered the first humbucker.
Gibson’s Seth Lover was working on a similar design at the same time and filed his patent first. However, the Gibson humbucker and its descendants have key differences from the Filter’Tron in both design and sound.
The 1970s were an unpopular time in Gretsch history, with Baldwin obtaining ownership of the company from 1967 to 1985. The period is highlighted by a dramatic decrease in sales, unpopular designs, and an overall decline in quality.
During this period, the recipe of the Filter’Tron changed various times, too. Magnets changed to ceramic, and the covers and pole pieces also evolved. A number of pickups of differing quality also began replacing the Filter’Tron altogether, such as the Blacktop Filter’Tron, HiLo’Tron, Mega'Tron, Super'Tron, and other iterations bearing the 'Tron name.
When Fender took charge of Gretsch recently, many of the Filter’Tron specs attempted to return to the original ‘50s models, such as with the return to alnico magnets.
Gretsch has also introduced the Broad'Tron on recent budget models. This pickup is much closer in sound and construction to a traditional humbucker.
TV Jones has been considered to make the most accurate recreations of Filter’Trons with Gretsch using his models in their own high-end instruments. Jones also makes updated versions, which help capture new sounds with the technology.
The uniqueness of the Filter’Tron compared to the PAF humbucker is rooted in the details. A Filter’tron is much narrower than a PAF, so the coils are closer together. The pole pieces are also 1/16” closer together than a traditional humbucker.
Early Gretsch pickups were also not soldered in place. The hook-up wire was simply clipped to the pickup. Filter’Trons also use a magnet that is nearly twice as large as a traditional PAF magnet. The bobbins are also taller than PAF bobbins, which contributes to brighter tone.
While fundamentally a humbucker, the Filter’Tron and the PAF humbucker are miles apart sonically.
Tone
The tone of the Filter’Tron is what has kept this unique beast around and successful for so long. It is hard to separate the sound from the “Great Gretsch Sound” where these pickups began. It is worth noting that these pickups were conceived and chiefly employed in fully hollow guitars usually equipped with a Bigsby.
Simply put, the Filter’Tron has the warm humbucking tone of a PAF and the brightness and clarity of a single coil. Many have tried to explain how this is achieved. The leading contending ideas are lower output, a narrower string window, and narrower coil construction. These will be discussed further when we dive into adjustment.
A wide array of players embrace the Filter’Tron’s signature sound, spanning from Jazz to New Wave. Players such as Chet Atkins, George Harrison, Brian Setzer, Malcolm Young, and Billy Duffy have extremely different tones and play in different genres but still are devoted to the same pickup.
Clean, the Filter’Tron has a beautiful jazz sound without the inherent muddiness that a PAF sometimes exhibits. When slightly overdriven, it is the sound of rockabilly. These pickups have a treble snarl that is just on the pleasant end of strident without becoming too harsh. These factors combine to make the Filter’Tron a great bridge between the Fender and Gibson sound, carving out its own signature sonic space.
Adjustment
Adjustment of a Filter’Tron is a bit more tricky than a traditional PAF-style humbucker, as there are 12 adjustable pole pieces in addition to the overall height adjustment screws. With Filter’Trons, less adjustment is considered more when dialing in your sound. The two key points are with addressing pickup adjustment are output and height.
Output
The pickup industry uses DC resistance (DCR) to represent the output or strength of a pickup. The higher the ohms of DCR, the stronger the pickup is considered. While this does not tell the complete story of the sound of the pickup, it is a useful reference point.
For example, a Seymour Duncan JB Humbucker has an DCR of 16k (fairly high) and Fender Stratocaster “Fat '50s” pickups have a DRC of about 6k (medium low). Filter’Trons typically have a DCR of 3k-5k, which seems very low.
However, due to the size of the magnet and the tall and narrow configuration of the coils, Filter’Trons are considered to be on the louder side of the pickup range. This lower output allows the pickups to keep the single coil clarity, while the construction allows for humbucker warmth.
Height
Filter’Tron master TV Jones actually recommends not adjusting the pole pieces on your Filter’Trons, as the large magnet is the source of the tone of the pickup. As the magnet is further away from the strings in a traditional humbucker (as a result of the taller bobbins), Filter’Trons sound best when very close to the strings. I find this especially true when using heavier strings, especially if you are using a wound G for classic rockabilly sounds.
TV Jones recommends the neck pickups to be 3/16” from the strings and the bridge to be 5/32” from the strings. This is the top of the pickup, not the pole pieces. For my Gretsch Center Block model with set up with 0.10 gauge strings, I have the bridge pickup set to 0.050” from the strings and the neck at 0.110” from the strings. I do raise the pole pieces under the wound strings a bit to add more clarity to the bass frequencies.
Filter’Trons are a great pickup to experiment with and are becoming easier to install, with companies like Lollar offering them in traditional humbucker casings. TV Jones also makes mounting rings that will fit traditional-sized models into any guitar. These aftermarket solutions have made Filter'Trons one of the easiest pickup swaps out there that will give you an entirely different palette to work with.