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 understandIf 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.
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.
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