[WaveTheory]

This problem is slowly driving me nuts haha

For sure! That noise gets irritating quickly.

USB isolators I've used like ifi defender/silencer only reduce the noise by a little bit

I had the same problem.

I'm curious about what the fixes are

Disclaimer: USB ground loops can be super hard to get rid of. Cheaper fixes may only have limited effectiveness, or they could knock it out. It all depends. Let's go cheap to expensive:

1) Run optical instead of USB - if you can. You mentioned using the optical input in a previous post, IIRC. If your PC has an optical out, just use that and disconnect USB entirely. You'll still need to use a wall wart and USB power cable for the Modi, tho.

2) Get an in-line ground loop isolator and put it between the dac and the amp. This type of thing: https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_5?dchild=1&keywords=rca+ground+loop+isolator&qid=1625512384&sr=8-5. This worked well for me. The only time I heard the ground loop noise was when the pots on my amps were near maxed-out.

3) Get a DDC (digital-to-digital converter) with good USB noise isolation. These get pricey. The Matrix Audio X-SPDIF 2 and the Singxer SU-2 are gonna be the starting points an they're both in the neighborhood of 400USD.

4) Go completely balanced between your DAC and amp...which would of course require new dac and amp. Using balanced connections between your dac and amp will naturally reject that ground loop noise. But, it ain't cheap, and balanced tube amps are quite rare.

I'd start with 1 or 2 or both and see what it does for you. Good luck!

 

[Epika07]

For sure! That noise gets irritating quickly.



I had the same problem.



Disclaimer: USB ground loops can be super hard to get rid of. Cheaper fixes may only have limited effectiveness, or they could knock it out. It all depends. Let's go cheap to expensive:

1) Run optical instead of USB - if you can. You mentioned using the optical input in a previous post, IIRC. If your PC has an optical out, just use that and disconnect USB entirely. You'll still need to use a wall wart and USB power cable for the Modi, tho.

2) Get an in-line ground loop isolator and put it between the dac and the amp. This type of thing: https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_5?dchild=1&keywords=rca+ground+loop+isolator&qid=1625512384&sr=8-5. This worked well for me. The only time I heard the ground loop noise was when the pots on my amps were near maxed-out.

3) Get a DDC (digital-to-digital converter) with good USB noise isolation. These get pricey. The Matrix Audio X-SPDIF 2 and the Singxer SU-2 are gonna be the starting points an they're both in the neighborhood of 400USD.

4) Go completely balanced between your DAC and amp...which would of course require new dac and amp. Using balanced connections between your dac and amp will naturally reject that ground loop noise. But, it ain't cheap, and balanced tube amps are quite rare.

I'd start with 1 or 2 or both and see what it does for you. Good luck!

Thanks a lot for typing all that out I really love this amp's sound so it's just a bummer to have to put up with the noise

My PC doesn't have an optical out unfortunately, so I think option 1's out haha. The Amazon link for option 2 links to moon-audio?

 

[WaveTheory]

Thanks a lot for typing all that out I really love this amp's sound so it's just a bummer to have to put up with the noise

My PC doesn't have an optical out unfortunately, so I think option 1's out haha. The Amazon link for option 2 links to moon-audio?

So it does. Grumble. Try this: https://www.amazon.com/PAC-SNI-1-No...ca+ground+loop+isolator&qid=1625520114&sr=8-5

 

[Epika07]

So it does. Grumble. Try this: https://www.amazon.com/PAC-SNI-1-No...ca+ground+loop+isolator&qid=1625520114&sr=8-5

Is it the PAC SNI-1 Noise Isolator?

 

[WaveTheory]

Is it the PAC SNI-1 Noise Isolator?

Yes

 

[Epika07]

Yes

Damn... it's not available on Amazon UK

 

[WaveTheory]

Damn... it's not available on Amazon UK

Was afraid of that. There are a variety of similar products, though. I'm sure you'll find something that is the same type of thing. Good luck!

 

[Epika07]

Yes

I found this https://www.amazon.co.uk/AV-Link-Gr...WB9O/ref=dp_prsubs_2?pd_rd_i=B000NVWB9O&psc=1 but not sure if it would do the same thing

 

[WaveTheory]

I found this https://www.amazon.co.uk/AV-Link-Gr...WB9O/ref=dp_prsubs_2?pd_rd_i=B000NVWB9O&psc=1 but not sure if it would do the same thing

It should. I can't speak for the individual model, but under 10 pounds it's very low risk to find out if it works.

 

[Epika07]

It should. I can't speak for the individual model, but under 10 pounds it's very low risk to find out if it works.

Yeah I'll just get it and return it if it doesn't work. Fingers crossed!

 

[dougms3]

Have you tried isolating the power cable plug for the amp?

If you have it connected to a power strip, try plugging it separately from other devices. ie Directly into wall outlet by itself.

 

[Epika07]

Yeah I'll just get it and return it if it doesn't work. Fingers crossed!

Super happy to report that the ground loop isolator has completely eliminated like 95% of the noise, all I can hear now is a faint hiss and a barely audible hum, no more annoying noise when I move my mouse etc. Glad that I only had to spend £8 for this fix. Now I can finally fully enjoy this amp! Btw, what tubes are recommended? I see people saying Gold Lion and PSVane are good but for 12AU7 or EL84?

 

[Epika07]

Just installed 12AU7 Gold Lions today and one of the tubes aren't lighting up, should I be worried? Could it be that I installed them incorrectly?

 

[WaveTheory]

Just installed 12AU7 Gold Lions today and one of the tubes aren't lighting up, should I be worried? Could it be that I installed them incorrectly?

Hmmm, usually tubes only go in one way. Make sure it's pushed all the way in. If that doesn't help, it could be a bad tube. To check just out the old tube back in and see if it lights up.

 

[Epika07]

Hmmm, usually tubes only go in one way. Make sure it's pushed all the way in. If that doesn't help, it could be a bad tube. To check just out the old tube back in and see if it lights up.

Tried removing the tube and inserting it back in which fixed it, probably didn't push it all the way in the first time like you said. It's a little difficult to know for sure if the tubes are seated all the way in because of the glass panel inside the amp haha. Time to burn-in these new 12AU7 Gold Lions and EL84 PSVanes