I have built the K8060 kit and connected it as per the diagram in the manual, and performed the light bulb test. On first switch on it worked fine then blew R20 taking out R5/R6 and almost all the transisters on the board. Presuming that it was somthing i did, maybe put too higher input in (its connected to a handheld battery operated MP3 player) I rebuilt it replacing all damaged components with like for like new. Switched on, and for 2 weeks everything ran fine. Today the amp was powered, no input signal (the MP3 had no battery in it) and the 8ohm speaker disconnected as it had been previously without any problems, when T4 blew, taking R19, R16, R17, R4, D2 visibly damaged and i havnt checked the rest as yet. Do you have any thoughts on what may have happened on this occasion? Ive looked through the circuit diagram, and cannot see what may have occoured to cause this damage.
Many thanks in advance for your suggestions/assistance.
Please check other posts on this item. Most likely, the problem is caused by either an assembly problem, poor soldering, insufficient heatsinking or intermittent contact in the transformer wiring. In any case, replace all semiconductors and damaged passive components. Clean the board to remove all carbon traces. Make sure to get exact same types of spare components. Pay attention when mounting the power transistors. Use isolated types. Have a friend take a look at your assembly.
Thank you for your prompt reply.
The heatsink used, is as specified in the instructions, and all soldering has been double checked. All compnants are identical to those supplied in the original kit, and all componants double checked by “a friend”. Transformer has not been checked so far, but does appear to be giving expected outputs.
I have been useing the K8060 poweramp directly after a K1803 preamp stage, and now notice a resonating sawtooth appears between the stages when they are connected together without an input signal. The signal appears to run at approximatly 100kHz. Are these two kits compatable?