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Start up and shut down noise
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Posted on August 2, 2016 at 10:45:31 | |
Posts: 669
Location: Guber Ohio Joined: December 30, 2005 |
Kevin, Been a while since I have posted. I have been working on several PPP and CFSEP projects. I have been able to achieve some good results sonically but I have had some interesting oscillations (weird sounds) on start up and shut down. My PPP amp employs cathode feedback through the primary of the OPT. I get a weird oscillation on start up when I use old stock EL84s in the output stage but only on certain speaker drivers. This does not happen using new stock EL84s. Interestingly, when the new stock EL84s are used, I get a loud sound that sounds like a slow cork pop on shut down. This does not happen with the old stock EL84s which have issues on startup. On Cathode follower build, I get a motor boating sound on startup only when I use old stock 6L6 but not with old stock EL34s... Short of serious trouble shooting with multiple valve complements and much hair pulling, I would like to short the outputs with an "On delay" on startup and short the outputs prior to shut down to cover all scenarios. I see you have delay kit. Could this be implemented to cover most of this? Stuben |