In Norway that had been a well known problem. Most 557 delivered to N had the voltage set to 220V. Whereas we have a nominal voltage of 230-240V.
Meridian uses TO-92, paralleled to avoid TO-126/TO-220. The latter are more expensive. As can be seen from the pictures the small transistors are dropping too much voltage and getting too hot. Instabilities occur and the amp shuts down.
We used to exchange the boards, but with the age that has become more costly compared to street value of the amp.
You can try exchanging the transistors, but many times it just doesn’t work.
R
Meridian uses TO-92, paralleled to avoid TO-126/TO-220. The latter are more expensive. As can be seen from the pictures the small transistors are dropping too much voltage and getting too hot. Instabilities occur and the amp shuts down.
We used to exchange the boards, but with the age that has become more costly compared to street value of the amp.
You can try exchanging the transistors, but many times it just doesn’t work.
R
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Hi
This amplifier is in the UK and has been in use for years. I have not removed the PCB's yet but see no evidince of overheating.
I do not know the TO92 reference what transistors are you talking about?
"Q" what, and part number MPS// BC** etc.
thank you
P
This amplifier is in the UK and has been in use for years. I have not removed the PCB's yet but see no evidince of overheating.
I do not know the TO92 reference what transistors are you talking about?
"Q" what, and part number MPS// BC** etc.
thank you
P
As I said the amp is not stripped down just the top cover is off at the moment.
I wanted the transistor numbers you refer to as they are on the circuit
thanks anyway.
I wanted the transistor numbers you refer to as they are on the circuit
thanks anyway.
Phil, I made this comment based upon my experience with the 557. I have provided pictures to show discolouring in the area of interest. You, on the other hand, haven`t even taken the trouble to take the amplifier apart to verify if my hint can be applied to your specific amp. When, and if you do so, you will very soon see what transistors I was referring to.
Don`t expect me to hand you a solution.
R
Don`t expect me to hand you a solution.
R
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