What is the fine-grained topic of the following text: The 3-way Oak Grigsby switch allows for 'Tone Bypass' in Position 1, 'Tone Enabled (NOS Russian PIO .047 Cap)' in Position 2 and a 'Fixed Notched Tone (Sprague Vitamin Q .0015 Cap) in Position 3. Only return the topic.
Oak Grigsby switch settings