Dual 100W High Power Two-Channel Pure Final Stage Dasiter Ocl Amplifier Board Second, the installation and production The printed circuit diagram of this circuit is shown in Figure 3. It includes a two-way OCL power amplifier circuit and a DC power supply circuit. A heat sink is required between the body of the 4 high power tube 2N3055 and the printed circuit board, and is fixed by screws. The resistors are installed horizontally. The capacitors and triodes are installed vertically and close to the circuit board. The soldering requirements are firm and reliable. There are two jumpers on the circuit board, which can be soldered with iron wires. Third, debugging The power transformer used in this circuit needs to be prepared by itself. It adopts a center-tapped dual output transformer (AC: 1 5VX2), the power is not less than 40W, and is connected to the AC~ and the upper part of the printed circuit board. After being energized, it is generated at both ends of C9 and C10. With a DC voltage of 18V, the voltage across the speaker is zero volts. First adjust the current of the differential amplifiers vt l, vt2, in order to avoid the large current flowing through the power tube, first short the base of vt4, vt5 with a wire, so that vt4 ~ vt7 cut off. Then solder one end of the resistor r6 to the ground and solder it to ground. The total emitter current of the differential amplifier stage is determined by r4. The R4 is adjusted so that the total emitter current of vt 1 and vt2 is 1 mA. After the resistor r6 is restored, the voltage across the speaker should be o. If there is an offset, adjust r3. Package Included: 1 x OCL Amplifier Board DIY Kit Product Features Circuit Board Size: Glass Fiber Board 22.4cm*7cm, Working Voltage: Double AC 12V Fully Separated Components, Four High-power Triodes, Two Stereo Channels, Each Channel can Reach to 100W. The Power Amplifier Circuit of Household Power Amplifier and Active Speaker has a Good Effect. This Power Amplifier Uses a Typical OCL Circuit, Which Has the Advantages of High Stability, Wide Frequency Response Range, Good Fidelity, etc. This Circuit is Often Used in High-Fidelity Sound Reproduction Equipment. This OCL Stereo Amplifier is Suitable for the Assembly and Uuse of Electronic Enthusiasts and Audiophiles. Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!