This amplifier has full rail voltage on the both speaker terminals .None of the outputs are shorted out ,what am i missing ? leaking outputs maybe
P.s. -amp powers on fine and idles nice 1.5-2 amp current draw
P.s. -amp powers on fine and idles nice 1.5-2 amp current draw
Confirm that you have both positive and negative rail voltage as well as positive and negative regulated voltage on the op-amps.
If you do, post a photo of the inside of the amp.
If you do, post a photo of the inside of the amp.
i do have both positive and negative rail voltage on the outputs ,but the op amps have 18v on leg8(Vcc) and 10v on leg 4(Vee)
there are 3 missing zener diodes -board location zd70 ,zd1 and zd2
do u have any info on those
One of the op amps is broken of the board its BA4558n can i use Njm4558L instead ?
do u have any info on those
One of the op amps is broken of the board its BA4558n can i use Njm4558L instead ?
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Does it appear that something was in the locations ZD1 and ZD2 or could they have been left out by the manufacturer (intentionally)?
The other missing diode (ZD70 is probably the same as ZD170 (?) on the other side of the green transistor.
The other missing diode (ZD70 is probably the same as ZD170 (?) on the other side of the green transistor.
It looks to me like the someone removed zd1 and zd2 ,not sure why ?Amplifier power on ,idles fine and produces good audio output the only small issue is that one of the channels have slightly lower power output that the other .Is it possible to be due the missing zenners or am i going crazy🙂
I don't know what the regulator circuit is in this amp. It could be that the board was designed for more than one model.
I'm assuming that the large resistors feed the collectors of the transistors standing near them and ZD170/70 are connected to the bases of those transistors.
I'm also assuming that ZD1 and ZD2 are connected between the large resistors and ground. That would make them useful as pre-regulators (with the transistors) or standalone regulators (if the transistors were not being used).
You say that one channel is lower. Is that due to the gain or does one channel clip at a lower amplitude than the other?
I'm assuming that the large resistors feed the collectors of the transistors standing near them and ZD170/70 are connected to the bases of those transistors.
I'm also assuming that ZD1 and ZD2 are connected between the large resistors and ground. That would make them useful as pre-regulators (with the transistors) or standalone regulators (if the transistors were not being used).
You say that one channel is lower. Is that due to the gain or does one channel clip at a lower amplitude than the other?
I have new one just got and the parts that are missing you are mentioning were not installed at factory I have ten plus 4558 jrc's, it is cheaper to order from china and wait the time for parts to arrive I bought like 20 for a deal, I do lots of repairs and just got one of these amps does anybody know the resistance of the level control pot closest to the rca inputs, I need to buy a new one it is missing.
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