I have a echolette b40n head that sounds like I play it through a ring modulator or something similar. This usually starts 10-15 minutes into band practice (when the amp is getting warm?)I have cahnged the three preamp tubes and the two el34s. The only tube I havent switched is a gz34. I was told where I bought the tubes that this wasnt necessary to change as long as sound came from the amp. Anyone know what it can be?
Is it possible that you could be experiencing extremely bad microphonics with your tubes....were your replacements new?? What Brand...Russian tubes tend to suffer this problem OCCASIONALY. Have your tubes been checked for microphonics??? Does amp start to hum/ hum louder as it warms up? I'm getting a little out of my league here now, but I THINK the capacitors in your amp could cause this. let me know what you find out for my future reference. Zappa jr.
Thanks for your help. I switched the tubes with new ones. The preamp tubes are russian. I dont know what the EL34 tubes are, but I bought them new I think. It may very well be the capacitors though. It is an old amp and I dont really know what is`s been through. Just to mention it there are four inputs on the amp, and when I switch input the problem seems to go away for a few seconds.