Soundstream P204e USA problem

Hello, I have amplifier Soundstream P204e USA series. Recently it stopped working, when checking found that burned down two transistors part no ndp6060 and two transistors 2SA1562. Can't find the analogues of those of these transistors, what can be replaced and may have circuit for this amplifier?
 

DeHchik

Member
2016-03-14 10:57 pm
Russia
Hi,
I replaced the transistors on 2sa1562 Russian analogue КТ639В, 2 pieces part no ndp6060 replaced the IRFZ48N. Instead of fuses connected the lamp, when switched on, the amplifier is operating normally, nothing is heated, but if you turn up the volume, then begin to heat output part no tip102 and TIP107 transistors on the first channel and the lamp starts to light up.
 
That's up to you. I recommend against it. It insulates the windings which can make the transformer run hotter. It also make repairing minor problems more difficult. Unless the amp is going to be mounted where it's audible, I wouldn't do anything other than maybe move the windings slightly to see if that helps.

I'm assuming that there is no problem with the drive circuit, snubbers, etc... making the transformer noisier than normal.
 
Hi all, not had time to write. I have one more question from the past owner on this amp the fuses are blown, he replaced them, but they immediately burned out. He gave this amp to repair shop after repair it worked for half a year and came to me with the breakdown described in the beginning of this post. When I opened it it turned out that in the fourth channel there is no complementary pair part no TIP102 and TIP107 and is not regulated by a high pass filter (photo attached). Does anyone know why this was done in the repair shop?





 
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If the missing transistors are parallel to the installed transistors and the channel is functioning, the channel will not be able to withstand lower impedance loads reliably. If you replace the missing transistors, you also have to replace the transistors that are connected in parallel with them. Parallel transistors are going to share the load more evenly if they are closely matched. Having matching date codes generally means that they are relatively closely matched.