Faulty DAC advice please

[Fandango Andy]

I purchased an SMSL SU-1 about 15 months ago and have been very happy with it. Unfortunately it has developed a fault. I have sent a message to the seller but don't anticipate a response for a few days so thought I would post here in case anyone has any ideas.

It powers on as normal, and scrolls through the inputs as normal it just doesn't sound right. The sound is quiet and crackly, imagine an FM radio just a off tune.

I have checked everything I can think of:

• Different source
• Changed optical cable
• Changed RCA's to the amp
• Checked all cables are correctly fitted.

Finally I tried a different DAC just to make sure the issue wasn't with a different component.

Any ideas what the problem could be and what the fix could be?

 

[Gray]

You've tried it with different sources Andy, but have you tried it on all 3 inputs with the same result?
I only ask because if by chance it was OK on USB input, it might be a problem with your 5 volt power supply (although you may have already swapped that to check).

 

[Fandango Andy]

You've tried it with different sources Andy, but have you tried it on all 3 inputs with the same result?
I only ask because if by chance it was OK on USB input, it might be a problem with your 5 volt power supply (although you may have already swapped that to check).

No, I hadn't tried either of those things. I only use it with a WiiM Mini who only digital out is optical. I hadn't considered the power supply, but have just tried a different one, and no difference.

Thanks for the ideas.