New: In partial Kit form Designed to eliminate the probability of poor quality modules Discrete design allows for simple build, repair and excellent long term reliability No worries of parts going obsolete, since there are multiple manufacturer sources HS is fitted for STK-0025 through to STK-0105 Not for beginners. Specialized tooling and skills are required Prior Audio Electronic knowledge and interpretation is required We will ship these kits internationally All shipping charges will be calculated by eBay Upon shipping you will receive a message providing the links to the Mouser shopping cart to order the parts and the online documents with pictures Note: No returns, all sales are final. If you change your mind after sale and item has not shipped, we can refund if asked Electronic Components are not included in this kit, you are responsible to source and purchase as the buyer There are other STK kits listed that contain the all the parts for you to assemble. There is also fully assembled & tested STK's made available Weigh your options based on time, ability, cost, ease Listing is for, two blank PCB's (of your choice), two heatsinks and M3 screws as shown in the main photo We now have two pcb designs available using the same heatsink STK-0050 STK-0050-II Please make a note to seller to indicate when you order which pcb type you require? Both types have been tested in a Pioneer SX-780. STK-0050-II offer slightly better THD performance and parts are a bit more expense tested in a SX-680 Heatsinks are tapped for M3 x 0.5 screws, provided Limited support Refer to the images of the completed modules once they are assembled and installed The completed modules will cost around $75.00 in materials, total for two modules. Add ~$5 for STK-0050-II The module will improve the amplifier's reliability and operational specs for sets using the STK modules up to ~90 watts Outputs are spec'd for using TO-3PN devices, either 150W or 200W devices can be used, Toshiba or OnSemi Bias adjustment included in circuit, making modules adjustable for matched performance These designs have been successfully used in other Pioneer, Fisher and many other models that use STK types modules. Output transistor bias adjustment and temperature sensing is included in the circuit design This allows for the modules to be adjustable for matched performance You can use this design to replace STK-0040, 0050, 0070, 0025, 0029, 0039, STK-0040-II, 0050-II, 0070-II The integral heatsink part is larger than the original STK footprint but uses the same mounting holes. Please verify for fit in your application The HS is 96mm wide x 37mm high. The top of the heatsink is 15mm from the mounting holes Heatsink is tapped for M3 x 0.5 screws, supplied Expected Performance: STK-0050 Total Harmonic Distortion: ~< 0.02%, 20-20KHz, 4-8 ohm, 31mA bias STK-0050-II Total Harmonic Distortion: ~< 0.01%, 20-20KHz, 4-8 ohm, 31mA bias Gain = 19.37/1.25=15.5 (23.8 dB) (SX-780 design) Emitter resistors are 0.22ohm, that would be 0.22 *0.031A = 7mV across each emitter R or 14mV across the two of them, Emitter to Emitter. Increasing the bias current will make the o/p's run a bit hotter, but lower the THD slightly and increase the class "A" region. Note II: Reference and component subs: Google: "STK-0050 Replacement for SX-780 and others" :Audiokarma site Read before ordering |