Bourns has expanded the standard resistance values of its PDB182-GTRB Series 17 mm blend‑balance guitar potentiometers, extending the range from 10 kΩ up to 1 MΩ according to the manufacturer datasheet and press release.
This gives instrument makers and audio equipment designers more tonal and signal‑routing options without changing the mechanical layout or requalifying the potentiometer footprint.
Key features and benefits
- Broader resistance range on one platform – Standard values now span 10 kΩ to 1 MΩ on the same 17 mm mechanical platform, simplifying design reuse and giving OEMs a wider choice of tone and blend characteristics without PCB changes.
- Blend/balance focused design – Dual‑gang construction with a center detent provides a clear mid‑position and repeatable adjustment for pickup blending, channel balance or wet/dry mixes.
- Compact 17 mm package – The L17 mm form factor suits densely packed control cavities in guitars and basses as well as compact mixer and synth front panels.
- Carbon resistive element – A carbon track is used for smooth, consistent wiper contact, which helps reduce scratchy noise and improves perceived feel during rotation.
- Mechanical robustness – Metal shaft and metal bushing construction supports repeated actuation, which is important in stage instruments and pro‑audio gear that see frequent use.
- Flexible shaft and termination options – Plain or knurled shaft variants support different knob designs, while rear solder lugs or PC pins allow either hand‑wired harnesses or PCB mounting.
- Standard audio tapers – Availability of M and N tapers across the resistance range is suited to common audio volume, tone and blend curves without resorting to custom parts.
- Environmental compliance – The series is RoHS compliant based on the applicable directive, which eases adoption in global designs.
Typical applications
The PDB182-GTRB Series is targeted at audio and musical‑instrument controls where a precise center position and smooth transition between two signals is required.
- Electric and bass guitars with pickup blend controls in place of a conventional three‑way switch.
- Guitar and bass amplifiers for channel blending, effects loop mixing or presence/contour controls.
- Studio and live sound mixers for pan, balance or group blend functions in a compact mechanical format.
- Synthesizers, drum machines and grooveboxes for mixing oscillators, layers or effect sends/returns.
- Pro‑audio and broadcast equipment where front‑panel blend/balance controls require a tactile center detent.
- Consumer audio and multimedia devices, such as powered speakers or small mixers, needing simple left/right or wet/dry balance.
- General‑purpose audio control circuits that benefit from dual‑gang, center‑detent behavior.
Technical highlights
The most relevant electrical parameters for design‑in are:
| Parameter | Typical value / notes |
|---|---|
| Resistance range | 10 kΩ to 1 MΩ standard values |
| Resistance tolerance | ±20% |
| Taper options | M and N audio tapers |
| Power rating (dual section) | 0.06 W |
| Operating temperature | −10 °C to +50 °C |
| Rotational life | 15,000 cycles (typical for this series) |
| Construction | Dual‑gang, carbon element, metal shaft and bushing |
| Mechanical size | 17 mm potentiometer body length (series designation L17) |
A resistance range up to 1 MΩ allows these potentiometers to interface comfortably with high‑impedance guitar pickups and line‑level audio stages without excessive loading. At the lower end, 10 kΩ values can be useful in low‑impedance or buffered stages where designers want tighter control over signal levels.
The ±20% resistance tolerance is typical for carbon‑element panel controls and is generally acceptable in audio applications where exact absolute resistance is less critical than taper consistency and tracking between gangs. The 0.06 W dual‑section power rating is adequate for control‑level signals rather than direct power handling, so the devices should not be used where significant dissipation across the track is expected.
The operating temperature range from −10 °C to +50 °C covers typical musical‑instrument and indoor pro‑audio environments; if extended industrial or automotive temperature ranges are needed, a different product line would be more appropriate.
Design‑in notes for engineers
For circuit designers and hardware engineers, the main value of this update is the ability to fine‑tune pickup or channel interactions without redesigning the mechanical interface.
- Match resistance to source impedance – For passive guitar pickups, higher resistance values (typically 250 kΩ to 500 kΩ or 1 MΩ) help preserve high‑frequency content and sustain, whereas lower values introduce more loading and darker tone.
- Choose taper based on user interaction – M and N tapers differ in how quickly the level changes around the center; select the taper that gives the desired perceived “sweep” during a blend from one source to the other.
- Use the center detent intentionally – The mechanical detent should correspond to an acoustically meaningful balance point; in many designs this is the equal contribution of the two sources, but in some cases a slight offset is acceptable.
- Check dual‑gang tracking requirements – For precise stereo balance or two‑channel control, verify in lab builds that the tracking between gangs is sufficient, especially near the center detent.
- Confirm thermal limits in unusual use cases – While these potentiometers are intended for low‑power audio signals, verify that any DC bias or series resistance in your design does not cause excess dissipation beyond the 0.06 W dual‑section rating.
- Account for rotational life in high‑use controls – With a specified rotational life of 15,000 cycles, these parts are well suited for typical instrument and audio controls; however, extreme high‑duty applications (for example, training or rental equipment) may warrant verification of wear margins.
- Standardize mechanical variants – To simplify both manufacturing and field service, limit the number of shaft and bushing options used per product line and clearly document knob compatibility in the mechanical drawings.
- Treat environmental specs as indoor‑focused – Given the −10 °C to +50 °C operating range, avoid placing these parts in enclosures with poor thermal management in outdoor or high‑temperature environments.
From a layout perspective, the ability to keep the same 17 mm footprint and panel hardware across multiple resistance options makes it practical to design one PCB and enclosure set that serves different SKUs, differentiated only by the installed potentiometer configuration.
Source
This article is based on information provided in the official Bourns press release for the PDB182-GTRB Series and the associated product documentation and datasheet, with additional independent commentary for design engineers and component buyers.
