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Help needed with Lectron JH 50 Amp

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astro_nut

Member
Joined 2004
Hello,

I have a Lectron JH 50 amp which I love but recently has stopped working. Opening up I noticed that the power supply board under the power transformer has burnt out (see the attached picture). There is an ic chip with the number erased. I believe that this power supply board eventually fails. I have tried to contact the Swiss manufacturers of the Lectron JH 60 amps and Nick Doshi who I believe modifies these amps but have had no reply to my queries.

I believe that other members have had similar problems. Does anyone have a schematic for this amp? Or if anyone has a working replacement for the damaged board in question I would be glad to follow your design with kind permission. Any suggestions are welcome.

Many thanks.
 

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A

astro_nut

Member
Joined 2004
HollowState, yes you are probably right about it being a 555. It is a timer for the relay.

Jose, thank you for the info. Unfortunately the eBay seller does not have a schematic. I wonder if anyone has a copy of the old French magazine L'Audiophile. Apparently there was a schematic in issue #41 or 42 (I forget which). If someone has a copy I will be glad to purchase this.

An alternative is to redesign the whole power supply.
 
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