Lumin U1 Mini locking/hissing noise issue with Denafrips Pontus II DAC

Hi all - I’ve had this occasional problem for a while now, I’ve even just had a replacement DSP board from Denafrips but this hasn’t helped. The situation is specific… if I leave the DAC on (not on standby) and I allow the Lumin U1 Mini to go into sleep mode after a certain time, when the streamer comes on and attempts to play music I get a loud distorted hissing noise all mixed into the music. It sounds like a DAC locking onto the stream issue to me. If whilst the music is attempting to play I turn the DAC into standby mode and then on again via the front power button then it locks onto the signal and all is well.

Now if I put the DAC into standby mode after every use and let the Lumin power down into sleep mode as usual, I would then press the power button on the the DAC to power it up out of standby and following this when the Lumin starts up it plays with no problem.

I was just wondering if anyone else uses the Lumin with a Denafrips DAC and has encountered anything like this? I am using the AES connection as that seemed to be the nicest sounding to me when I put the system together three years ago, I haven’t tried other connections as yet, as its only occasional it could take weeks before it happened again! :blush:

This happened to me yesterday. I powered on my preamp and there was quite a loud noise, which slowly diminished away after anout 30 sec. The lumin was in sleep mode and the Pontus was left on. I just put this combination together.

Probably a issue with the R2R dac… it’s outdated technology for a reason. I had similar problem with a hifiman R2R Dac and got rid of it

I haven’t had an issue since I turn the Pontus into standby every night, I used to leave it on all the time and occasionally I would get this noise.