[sdiy] Yamaha CS30 repair

[Doug Jackson]

These two diodes simply form a bridge rectifier.

Your choice on 1N4001 is completely appropriate.

There is nothing remarkable with the power supply.  A 1.6 amp fuse suggests
that the supply doesn't provide more than 1amp.

On Fri, 26 July 2024, 9:25 am Michael E Caloroso via Synth-diy, <
synth-diy at synth-diy.org> wrote:

> Schottky diodes have a lower reverse peak voltage than silicon diodes, and
> the reverse leakage current increases with increasing reverse voltage.
> Once you exceed the maximum reverse voltage, the component is permanently
> damaged.
>
> Not a good idea for a rectifier in a power supply.
>
> MC
>
> On Thu, Jul 25, 2024 at 1:52 PM Oren Leavitt via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>> I'd go with standard 3 amp diodes. e.g. 1N540x, et al
>>
>>
>> - Oren
>>
>>
>> On 7/25/24 12:13 PM, Kevin Walsh via Synth-diy wrote:
>>
>> Hi all,
>> I have a Yamaha CS-30 in for repair that was dead on arrival. It only
>> needed the dual diodes (D1 & D2) on the PSU replaced to get it working
>> again.
>> I got it working by using two pairs of 1N4001's:
>>
>>    - One pair configured in common cathode
>>    - One pair configured in common anode
>>
>> Both secondary fuses were replaced with 1.6A fast blow fuses as per the
>> service manual instructions. Given this, I figured any 2 or 3 amp diodes
>> should work fine.
>> Being such a nice synth, I'd prefer to have the best long-term solution.
>> Should I replace them with Schottky diodes for their lower forward voltage
>> drop and efficiency, or stick with regular silicon diodes and opt for a
>> higher current rating?
>> Any tips or recommendations for specific diode models would be most
>> welcome.
>> Thanks,
>> Kevin.
>>
>>
>>
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