[Elegiac]

Alright.
I have an SMSL SD-793II DAC, I'm feeding it coaxial, and running RCA out to an SMSL SH-6.
When the unit is powered on but music isn't playing, and I turn the amp up past 2 o'clock I can hear a rapidly oscillating 'electrical' noise. Not a hum or a hiss.
I've worked through every piece in the chain, and the noise originates in the DAC and not anywhere else.
Another DAC in the same position, idling while powered on, makes no sound.
The sound is inaudible(?) when music is playing. I have snuck the volume up to maximum in-between tracks and in quiet parts of songs, and I can't hear it.

What to make of this? I haven't turned up anything through google yet. And I'm wondering whether it's affecting audio quality.
I don't need or expect a stellar performance from this piece of gear, but to my ear, it could sound... cleaner.

 

[Corti]

Alright.
I have an SMSL SD-793II DAC, I'm feeding it coaxial, and running RCA out to an SMSL SH-6.
When the unit is powered on but music isn't playing, and I turn the amp up past 2 o'clock I can hear a rapidly oscillating 'electrical' noise. Not a hum or a hiss.
I've worked through every piece in the chain, and the noise originates in the DAC and not anywhere else.
Another DAC in the same position, idling while powered on, makes no sound.
The sound is inaudible(?) when music is playing. I have snuck the volume up to maximum in-between tracks and in quiet parts of songs, and I can't hear it.

What to make of this? I haven't turned up anything through google yet. And I'm wondering whether it's affecting audio quality.
I don't need or expect a stellar performance from this piece of gear, but to my ear, it could sound... cleaner.

I’ve had similar issues with my SMSL SU6/SH6 stack. When I connected the SU6 DAC to my pc via USB-c and then RCA to the SH6 Amp I heard static noise when the Amp was on high gain and vol. pot past 2-3 o’clock. Only noticeable without music playing.

It did not happen when I connected everything the same way to my laptop though.

I read in some thread that an optical / toslink connection fixes the issue, and yes it did for me. I think In my case it is the motherboard or something within the desktop that leads to the noise.

What is the source that you are feeding the DAC with coaxial? Did you try a different connection, like optical?

 

[Elegiac]

I’ve had similar issues with my SMSL SU6/SH6 stack. When I connected the SU6 DAC to my pc via USB-c and then RCA to the SH6 Amp I heard static noise when the Amp was on high gain and vol. pot past 2-3 o’clock. Only noticeable without music playing.

It did not happen when I connected everything the same way to my laptop though.

I read in some thread that an optical / toslink connection fixes the issue, and yes it did for me. I think In my case it is the motherboard or something within the desktop that leads to the noise.

What is the source that you are feeding the DAC with coaxial? Did you try a different connection, like optical?

Man, this is on low gain haha. I'm just feeding it FLAC from a Topping M50.
I can try an optical cable... I feel like it's the DAC though. But I'll look into optical tomorrow for the hell of it.

 

[bigshot]

If it's the DAC, it's pretty seriously defective. Did you just buy it? Can you return it?

 

[Elegiac]

If it's the DAC, it's pretty seriously defective. Did you just buy it? Can you return it?

Ehh, not easily. I'd rather just write it off. Not keen on paying for shipping to Japan for a $90 item. After convincing the seller. That's when cheap stops being cheap.

Gonna try optical like Corti mentioned. Maybe it's just one faulty input, instead of a deeper electrical fault.

 

[bigshot]

Someone is selling factory rejects. I wouldn't buy from that place again. That happens a lot on ebay too. Manufacturers dump defective stock and returns as scrap for sale and someone buys it and sells it to someone hoping they won't try to get their money back.

 

[BobG55]

Someone is selling factory rejects. I wouldn't buy from that place again. That happens a lot on ebay too. Manufacturers dump defective stock and returns as scrap for sale and someone buys it and sells it to someone hoping they won't try to get their money back.

But, But … that would be … unethical …

 

[Elegiac]

With optical the the electrical noise is 2% less audible. But I just checked it on high gain for the first time. Wow. Noise and noise, of two different kinds now.

Sorta musical in a way. Oh well, it can sing its song in the bin.

 

[bigshot]

I’d get my money back. Did you pay with PayPal?

 

[uckexk]

I had a similar problem. My setup was PC->USB->D90SE->RCA->A90.
I suspected it was due to a ground loop, because PC->USB->D90SE->XLR->A90D was silent. Then I tried HS01 and the problem went away.

 

[bigshot]

Could it be a ground loop? That would be fixable. Perhaps try the DAC on a different rig.

 

[Elegiac]

Nope, by card over amazon. I'm honestly not going to pursue this one. Believe me, sometimes I do though. Mercilessly.

I've tried seeing if it's a ground loop and it wasn't. It's fine. By lucky chance the Sabaj D3 arrived in the mail today. It's silent in that position, just like my other DAC was.
It's got a nice middle-of-the-road Cirrus Logic sound... instant replacement

 

[bigshot]

Easy then. Amazon will take it back no questions asked.

 

[Elegiac]

Easy then. Amazon will take it back no questions asked.

I did check, and because it's outside of the free return period, I'd have to go through the seller first, and then pay for my own shipping. This time I really really really can't be bothered. I'll let you know next time I want to make a seller squirm, and you can advise me on what to say, I promise

 

[bigshot]

Oh… you always have to check it out during the first 30 days. That’s your guarantee period. I hate to see money wasted.