Thread: Bush SRP31
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Old 25th Jun 2016, 10:24 pm   #6
Radio tirana
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Join Date: Nov 2015
Location: Oxfordshire, UK.
Posts: 171
Default Re: Bush SRP31

Hi you will find several recent posts which cover the replacement of the Selenium rectifier on this forum. It helps greatly if you are able to measure the HT voltage first to establish if it is indeed low, if your player is a SRP31D it should be 215VDC. Secondly to establish if you have got the very necessary series resistor value right. You will need a 1N4007 and a series resistor, 330 ohm 10W is the most likely value if you don't have a voltmeter to check it.
Be aware that the resistor will get hot so has to be mounted away from any wires that
could touch it and that the diode has to be connected the right way round. The diode connects between the mains transformer and the smoothing capacitor it has a line marked on it, this end is the cathode and is connected to the smoothing capacitor the other end is called the Anode and connects to the mains transformer. The series resistor can go either between the diode and the transformer or between the the diode and the capicitor. Whatever you do make absolutly certain the mains plug is out when you are working on the amplifier.
These machines are well worth the effort and do sound great when working properly
Regards RT
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