yes bulb is also not glowing at all and some sound is audible without output transistors. so they are maybe bad . could it be that i get on one transistor 26v and on other 7 a proof ?
also sound is amplified with them but i have distortion so maybe because of bad one and good one is doing that amplification ?
If you are playing without output transistors - which is actually a VERY good initial check out step - it can’t properly drive an 8 ohm speaker. It CAN and should be able to drive a higher impedance load - say, 100-200 ohms. Put a 100 to 200 ohm resistor in series with a speaker and play it. It should sound clean, just low in volume. You can measure the true AC voltage at the output with a meter or scope. If you can get it up and running PROPERLY in this mode then it will almost always be safe with the outputs installed.
so you suggest that i measure voltage on output for transistors or ? i dont understand
You measure (or look at on a scope) the output voltage at the normal place. You should still be able to develop a couple volts RMS of clean signal driving a high z load. The tiny voltage across the speaker in series with it doesn’t matter much, but you should be able to hear clear vs. distorted.
i tested transistors again so so i guess that you guys can tell if its ok or not btw first i use black on collector and later i reverse it for each transistor
The iffy meter can still show a couple of volts RMS, as in the presence of a “large” signal. Monitoring through a speaker (attenuated by the 100-1k ohm “load”) can tell you what it sounds like. BTDT. Got a little better when I managed to score an old green screen uncalibrated scope for $30 at a hamfest.
To me these transistors are OK. Thanks for the clip.
And I think your meter is more then good enough for this project.
This is a 10% amp, not something that needs to fly to the moon 🙂
Hugo
And I think your meter is more then good enough for this project.
This is a 10% amp, not something that needs to fly to the moon 🙂
Hugo
if transistor works what is a issue then xdd i thing we are really close to fixing it so what is a issue now 😀
Mount the transistors and record a short clip with some music so we can hear how it plays.
Don't play it too loud, just normal level.
Don't play it too loud, just normal level.
sure i will do it but i will record audio with my studio mic not with phone and go pro so quality should be accurate 😀
Make sure the mic level is not too high to avoid distortion.
Make it simple music, like some piano and / or a female voice.
Make it simple music, like some piano and / or a female voice.