I bought the original ELEKIT TU-8600 AMP KIT a year ago and I installed ELECTRO-HARMONIX 300B GOLD GRID tubes. When I put together the kit it worked perfectly from the moment I turned it on. A few weeks ago the tube on the left side failed. I turned off the amp within a few seconds of the tube failing. I purchased 2 new ELECTRO-HARMONIX 300B GOLD GRID tubes and replaced them. When I turned the amp on I got a hum for about 15 seconds or so then it stoped. The amp did not do that before... Both tubes glowed (after about a couple of seconds) when I turn it on. Then the side that failed stops glowing for a second, the humming stops, and then the tube glows again. It turns out that the humming stops because the channel was not producing any sound at all.
I contacted Elekit and then Elekit connected me with Victor. Victor KINDLY helped me troubleshoot the issue. After taking the voltage readings we were able to identify the general area on the board that had the failed component. I desoldered the transistors FETs and diodes in the area and using this tool from Amazon (https://www.amazon.com/Multifunctio...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==) I was able to identify the component that failed.
When I replaced the part (a transistor) I tested the voltage again only to find that further into the circuit I had another failed component. I tested the components around the next area again with the above mention tool to find that a diode had also failed. Once I replaced that part the amp worked perfectly.
Apparently the original tubes that I purchased were inexpensive but don’t have a long life and can cause these types of issues. I have replaced those tubes with the Cossor LINLAI, i changed the driver 12AX7 to Gold Lion ECC83/B759 and the 12AU7 tube to Brimar ecc82.
After a week or so of using the amp I am thrilled with the results. I can’t wait to build another one of these. I thoroughly enjoyed putting this kit together the first time and I learned a ton troubleshooting the repair. Overall excellent experience.
THANK YOU VICTOR FOR ALL YOUR HELP!
I contacted Elekit and then Elekit connected me with Victor. Victor KINDLY helped me troubleshoot the issue. After taking the voltage readings we were able to identify the general area on the board that had the failed component. I desoldered the transistors FETs and diodes in the area and using this tool from Amazon (https://www.amazon.com/Multifunctio...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==) I was able to identify the component that failed.
When I replaced the part (a transistor) I tested the voltage again only to find that further into the circuit I had another failed component. I tested the components around the next area again with the above mention tool to find that a diode had also failed. Once I replaced that part the amp worked perfectly.
Apparently the original tubes that I purchased were inexpensive but don’t have a long life and can cause these types of issues. I have replaced those tubes with the Cossor LINLAI, i changed the driver 12AX7 to Gold Lion ECC83/B759 and the 12AU7 tube to Brimar ecc82.
After a week or so of using the amp I am thrilled with the results. I can’t wait to build another one of these. I thoroughly enjoyed putting this kit together the first time and I learned a ton troubleshooting the repair. Overall excellent experience.
THANK YOU VICTOR FOR ALL YOUR HELP!