Hello, It's great to see your enthusiasm for tinkering with your BOGEN DP16 amplifier. To adjust the frequency response of your amp and add more high-end extension, you can indeed experiment with different capacitors and resistors in the circuit. To nudge the response closer to 70Hz to 6kHz, you can consider replacing the existing capacitors and resistors with values that align with your desired frequency range. Increasing the capacitance values in the low-pass filter section and decreasing the resistance values can help boost the high-frequency response. However, it's important to note that modifying electronic circuits requires careful consideration and understanding of the overall circuit design. I would recommend consulting with experienced audio technicians or electricians who can provide guidance specific to your amplifier model and circuit configuration. They can help you choose the appropriate components and make incremental changes in a controlled manner to achieve the desired results. Keep in mind that modifying the circuit may have unintended consequences or require additional adjustments to maintain the overall performance and stability of the amplifier. So, proceed with caution and make changes in small increments to ensure you can evaluate the impact of each modification. Best of luck with your amplifier modifications, and I hope you achieve the desired high-end extension you're looking for! P.S. If you need further assistance or have more specific questions, feel free to ask.