e-licktronic Forum

Hello,

I think my HT/HC doesn't work because at first I put the 4558 in the wrong way in having forgotten to remove power supply in the same time. So quickly a very bad smell came and I found that I have powered this 4558 inverted and unsoldered, (so maybe some pins were connected and other ones not).

Do you think I have fried it?

Guillaume

AOP generally are fragile. If you have no spare malaysia 4558, you can try with something else, for example a TL072 or JRC4558D.

Thank you!

I found a lot of "TL072" on Conrad, which one do you think is accurate?

Ref: 1011512 - 62
TL72CP is ok, itsn't the original component but it'll work this. I'm building a TR8060 with TL072, it doesn't change much.

This must have less difference between malaysia4558 and JRC4558D.

Merci!

I finally changed the 4558 with a same one from another Yocto kit because the TL072 I ordered doesn't have a similar mark for the good way to insert it and I wanted to be sure. So I put a new 4558 and unfortunately the high tom still doesn't work...

Has someone an idea of which part could have been damaged when I put the 4558 in the wrong way?

I only hear the noise part of the sound in the High Tom sound, plus a little click when the Tuning parameter is high.

Also when it is accented, the click sound is higher, and also present even if Tuning parameter is low.

I finally succeed to resolve the issue with my high tom.

The desoldering of the 4558 was obviously difficult and many solder points were damaged. I did the continuity tests to be sure that every point was well connected to its track. Unfortunately the point 3 corresponding to ground was not visually on a track and I thought it was not planned to be connected, but it was this one which was deconnected!