fender sidekick 65 bass amp recurring problem

[robgrif]

Hi all
I have a fender bass amp sidekick 65 that had blown output transistors
sd1046e and were replaced with nte36 transistors
worked great for a while and now it looks as if at least one has blown again showing dc at speaker
what would cause the same output transistor to blow again?
what replacement transistor would be better than the nte36
to replace the original sd1046e that came with the amp?
thanks for any feedback to my questions that you might have
Regards
robgrif

[Twist]

After looking at the data sheets on both, the NTE36 looks more robust. You must have missed some other bad components. Recheck all other transistors, diodes and small value resistors. How long did the amp work after replacing the outputs, seconds....days ?

[olddawg]

Or...you have a voice coil bottoming out. Also high frequency oscillation could cause it. I have never been a fan of NTE subs. It's always best to use the correct parts IMHO.

[robgrif]

the amp functioned in total actual usage time about five to six hours of moderate use spanning about one month of time
i will check all components again to be sure
thanks for the suggestion
Regards
robgrif

[robgrif]

Or...you have a voice coil bottoming out. Also high frequency oscillation could cause it. I have never been a fan of NTE subs. It's always best to use the correct parts IMHO.

hi olddawg
the speaker is crisp and clear and the were no other symptoms noticeably present
when the amp failed and upon inspection every part that was originally replaced
previously is once again damaged perhaps there is some other problem causing the output failure that was not corrected in the circuit in previous repair
I agree original is better but in this case the original has been discontinued
that is why I was looking for a non NTE sub which would do the job for me
a transistor with same or better specs than NTE 38 original 2sd1046e, NTE 374 original 2sb631e , NTE 373 original 2sd600e
also I believe that the non NTE parts are a little less expensive
thanks for your help
regards
robgrif