Bush SRP31
 

Hi. I have a lovely old Bush SRP31 record player, used nearly every day, mostly for LPs. It has a bit of distortion on the sound. Could this be valves, or the cartridge? Valves look OK, and seem to be bright enough. The cartridge is a Ceramic F-2111 (?). Is this the right one for this player? Please help, as I love this old player, and would love it to sound just a bit better than it does! Ta muchly. Steve .

Re: Bush SRP31
 

Possibly a cartridge (or stylus) problem, but could, posibly more likely be to to capacitors in the amplifier circuit, particularly if waxed paper types were used. Read threads about 'that capacitor' and follow the advice given. Basically such capacitors should be replaced to avoid expensive, possibly irreparable damage to the output ransformer and other components.

Re: Bush SRP31
 

Not capacitors in these but low HT due to rectifier or speaker worn out cone are likely things

Re: Bush SRP31
 

Never heard of that cartridge. Sounds odd. How can valves "look" OK - do you mean they glow? Edward

Re: Bush SRP31
 

I had very poor volume and bad quality sound on one of these. I replaced the selenium rectifier with a diode, 1N4004 or 1N4007 I think it was, plus a resistor in series. I'm a bit of a novice with electronics and soldering so you don't have to be an expert to do this and You should be able to find threads about it on the web. I believe it is a routine improvement for these vintage machines and I would recommend it.

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

Re: Bush SRP31
 

Thanks for all the advice. You guys are top notch. S.