Wheel Volume Control for BTE Hearing Aid
Hearing Aid Volume Control PJ 77 for BTE, Model 7500

Hearing Aid Volume Control PJ 77 for BTE, Model 7500

We also offer the following hearing aid volume accessories:

Model No.Description
7000Volume Control PJ 185
4mm VC, Leaded Style Volume Control with Switch
01052.54mm Trimmer, Miniature Trimmer
1900Trimmer PJ 63 200Kom
1.9mm Trimmer, Ultra Miniature Trimmer
2500Button D 2800/PB 95
2.5mm Button Switch
1*0.18, 7*0.05, 7*0.032, 5*0.05, etc.Litz Wire Compliant RoHS, Structure can be customized

If you are interested, Please click the “Request a Quote” button in the lower right corner, contact our experts, and communicate the style, size, and quantity you need.

Hearing Aid Volume Control PJ 77 Features

  • Controls can be purchased with or without knobs
  • Choice of terminal lengths and styles
  • Choice of axle styles
  • Choice of resistance values and tapers
  • Knobs are changeable
  • Select from a variety of printed numbering styles

Hearing Aid Volume Control PJ 77 Specifications

Mechanical Data

Operating Torque<0.1 Ncm (0.05-0.09 Typ.)
End Stop Force.>2 Ncm
Mechanical Rotation260° + 10º
Pull Off Force for Number Wheel.>5 N
Electrical Rotation230º ± 20º

Environmental Data

Rotational Life>25,000 cycles
Soldering Temperature.260°C/500°F for 3 sec. or 315°C/600°F for 1 sec.
CleaningAqua wash (Alpha 2110), Ligroin, Ammonia, 10% solution with demineralized water

Electrical Data

Power Rating.<1 mW (max.)
Resistance TapersSee the “Electrical Taper” chart
Standard Resistance Tolerance±20%
Noise ResistanceRr <20 dB
Insulation Resistance>1 MΩ


Knob, HousingThermoplastic
BaseReinforced glass epoxy
Terminals.Gold-plated copper alloy
Resistive Element.Polymer
WiperGold-plated copper alloy

Model 7500 Wheel Volume Control Body style

Dimensions are shown in millimeters (inches in parentheses).
Potentiometers are shown in the center position.

Model 7500 Wheel Volume Control Dimensions

Terminal Length

[A] Threaded M1 x 1.2 mm
[B] Threaded M1 x 1.5 mm
[C] Unthreaded Ø 0.3 x 1.2 mm
[D] Unthreaded Ø 0.3 x 1.5 mm
[X] Special

[A] Ø 0.3 x 1.2mm
[B] Ø 0.3 x 1.5mm


The value is expressed by 4 characters, 3 of which represent significant digits. 4th K or M is a dual-purpose letter designating both value range (K for K ohms) and decimal point location.
Examples: 560K = 560 KΩ
25K0 = 25KΩ

Note: If less than 1 K ohms is required, specify exact number.

Electrical taper

To determine taper, see diagrams in “body style”.
Positive tapers are measured from a to b.
Negative tapers are measured from c to b.

Model 7500 Wheel Volume Control Electrical Taper

Number stamping

The knob style diagram shows the placement of the number on the knob.

Model 7500 Wheel Volume Control Knob Style
Placement on knob   a0III14
Without Numbering[00]
With Black Numbering[01][02][05][06]
With White Numbering[21][22][25][26]
Special Color Numbering[41][42][45][46]

Color Dot 1&2

Color marking identification of resistance values on the reverse side of parts.

Wheel Volume Control Color Dot

[01] BLACK
[02] BLUE
[03] BROWN
[04] GREEN

[06] PINK
[07] RED
[09] WHITE

Other Hearing Aid Volume Adjustment Accessories

Product PhotoModel No.Description
Leaded Style Volume Control with Switch 70007000Volume Control PJ 185
4mm VC, Leaded Style Volume Control with Switch
Miniature Trimmer 010501052.54mm Trimmer, Miniature Trimmer
Ultra Miniature Trimmer 19001900Trimmer PJ 63 200Kom
1.9mm Trimmer, Ultra Miniature Trimmer
Button Switch 25002500Button D 2800/PB 95
2.5mm Button Switch
Push Button Switch 24002400Push Button Switch PB-100-H01-T01-210
1.9mm Button Switch
Litz Wire for Hearing Aids10.18, 70.05, 70.032, 50.05, etc.Litz Wire Compliant RoHS, Structure can be customized

How to Order Hearing Aid Volume Accessories

Please read the parameter information above, fill in your choice in the form below, and submit, our professional partners will contact you as soon as possible.


    Your Choice


    Body Style

    Center Terminal Length

    End Terminal Length


    Electrical Taper

    Number Stamping

    Knob Color

    Standard Colors Available: 26, 27, 28, 29, 32, 33, 37.
    Additional Colors Available, See Color Chip Chart In Appendix.

    Base Plate Color

    12 Natural

    Custom Color Available Upon Request

    Color Dot 1

    Color Dot 2


    [ S] Standard
    [xx] Special

    Your name *

    Your email *

    Your message