Components

and DOWN points in the MOTM-820. These allow the MOTM-820’s own pots to be used as input attenuators whilst being able to set the absolute rise and fall times with the OMS-820. Feel free to make any changes to the circuit to improve or alter the performance. If you do, do drop the Oakley-Synths mailing list an e-mail and tell us all what you have done.

Most of the parts are easily available from your local parts stockist. I use Rapid Electronics, RS Components and Farnell, here in the UK. The OMS-820 module was designed to be built mostly from parts obtainable from Rapid Electronics.

The BC550 and BC560 devices are discrete low noise transistors. The former is NPN, while the latter is PNP. You can replace the NPN with BC549, and the PNP with BC559. Quite often you see an A, B or C suffix used, eg. BC550C. This letter depicts the gain or grade of the transistor (actually hfe of the device). The OMS-820 is designed to work with any grade device although I have used BC550C and BC560C throughout in my prototype.

The board mounted pots are Spectrol 248 conductive plastic types and are held onto the board with specially made Oakley pot brackets. Three pot brackets and an extra set of nuts are required and these are provided with the ‘pot bracket kit’. You could use any pot type you want, but not all pots have the same pin spacing. Not a problem, of course, if you are not fitting them to the board.

In the UK, Farnell, CPC and Rapid Electronics sell the Spectrol pots for a reasonable price.

For the resistors ordinary 5% 0.25W carbon types can be used for all values. In other Oakley modules I recommend the use of 1% 0.25W metal film types and because 5% types use a different colour code to the newer 1% types it may be prudent to use only 1% types to avoid confusion.

All the electrolytic capacitors should be radially mounted. The working voltage (WV) of the capacitor is not critical, but chose one that will fit on the board. I would use 25V for the 22uF and 63V for the 2u2 capacitors.

The pitch spacing of the polyester capacitors is 5mm (0.2”). These types come in little plastic boxes with legs that stick out of the bottom. Try to get ones with operating voltages of 50V, 63V or 100V. They may be called polyester film or metallised polyester capacitors.

L1 and L2 are leaded ferrite beads. These are little axial components that look like little blackened resistors. They simply consist of a single piece of wire going through the middle of a ferrite cylinder. They are available from most of the mail order suppliers. Find them in the EMC or Inductor section of the catalogues. Farnell sell them as part number: 108-267.

All ICs are dual in line (DIL or DIP) packages. These are generally, but not always, suffixed with a CP or a CN in their part numbers. For example; TL072CP. Do not use SMD, SM or surface mount packages.

MOTM-820, OMS-820 specifications

The Oakley OMS-820 and MOTM-820 stand out as exemplary models in Oakley's extensive range of performance eyewear, designed for both sports enthusiasts and everyday users. These models capture the essence of Oakley's commitment to innovation, superior optical technology, and stylish design.

One of the main features of the OMS-820 is its advanced lens technology. Utilizing Oakley’s High Definition Optics (HDO), the lenses provide exceptional clarity and optical fidelity. This technology minimizes distortion, ensuring that users have an unobstructed view, whether they are on the golf course, cycling, or participating in other outdoor activities. The lenses also come with Oakley's PRIZM technology, which enhances color contrast and visibility in various environments, allowing users to detect changes in terrain or obstacles more readily.

The MOTM-820, on the other hand, emphasizes adaptability and comfort. It features a lightweight frame crafted from Oakley’s proprietary O Matter material, which provides flexibility and resilience. This ergonomic design conforms to the shape of the wearer's face, ensuring a secure yet comfortable fit during extended use. The adjustable nose pads and temples further enhance comfort, making it ideal for an active lifestyle.

Both models incorporate Oakley’s innovative lens treatment technology, which includes anti-fog and anti-scratch advancements. This ensures that the eyewear remains clear in challenging conditions, whether users are facing misty weather or rugged terrains. Additionally, the UV protection offered by these lenses shields wearers from harmful rays, a critical feature for outdoor activities.

A striking characteristic of the Oakley OMS-820 and MOTM-820 is their customizable aesthetics. Available in a myriad of colors and styles, users can express their individuality while enjoying high-performance eyewear. This attention to style combined with functionality makes these models popular choices among both athletes and casual wearers alike.

In summary, the Oakley OMS-820 and MOTM-820 are distinguished models that integrate cutting-edge technology with comfort and style. Whether for competitive sports or daily wear, these eyewear options exemplify Oakley’s commitment to enhancing visual performance and user satisfaction.