That behaviour in a NE5532 is not normal at all. If you have an oscilloscope available you should check what is happening, either HF oscillation, a defective solder injecting signal from a nearby transmitter, or even a PSU regulator that is oscillating in HF too and passing through the bypass capacitors. Also check your layout and distance of the decoupling caps to the IC. You should check too for (lack of) ground loops.
On Friday, February 20, 2015 at 7:42:10 PM UTC-3, Mihai wrote: > > Well, in the mean time I received the IN-13s and they work absolutely > fine. Moreover, for one channel I put the LPF in front of the driver and > surprisingly enough it has no effect what-so-ever. I am working on the PCB > now and I hope I can do it one side only and a few straps on the top side. > PS: it seems there is a huge difference between LM358 and NE5532 dual op > amps. With the 1st it works fine but with the latter, though rated as newer > and better, the behavior is a bit hectic, the most notable is that with no > audio input the tubes stay lit all the way to the top. > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/446ffc44-81cc-4bf2-9aae-ea7e4240c600%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
