forget my cobramatic speaker-now tube question

monkfish1 · by **monkfish1** » Mon Feb 22, 2010 5:18 am

OK.. I took part of my cobramatic apart- got the speaker working.. but I think I have to find some new tubes! Does anyone know what the tubes for a zenith cobramatic are?? I see on line that there are a few places to acquire tubes.. does anyone have any recommendations?

Thanks!

martyfreeman · by **martyfreeman** » Mon Feb 22, 2010 5:34 am

There are likely more than one model of zenith cobramatics, which may use different tubes. There is often a paper tube chart glued to the inside or back of the cabinet with a drawing of the chassis showing the tube numbers.

However, unless the amplifier has been rebuilt by having the paper and electrolytic capacitors replaced, new tubes are unlikely to remedy the sound problems. The new tubes and also transformers can be damaged if the coupling capacitors are bad.

monkfish1 · by **monkfish1** » Mon Feb 22, 2010 6:12 pm

Thanks for the info! I had to look up what a coupling capacitor was and what the electrolytic capacitor is.. I did recognize the electrolytic. That was nifty. The reason that I thought it might be the tubes is that the speaker didn't work and then I made sure all the tubes were in properly and it did work, albeit not to the volume that it used to.
Thanks for your info!