[FellowTraveller]

longer cables (~3m or 5m lengths) are more likely to have link reliability problems, e.g. host doesn't see DAC, audio dropouts, frequent disconnects/reconnects,
etc...

AFAIK, for Bifrost/Gungnir/Yggy using galvanically-isolated variant of Unison USB interface, the digital source always provides power to the Unison USB interface circuitry.

For Modius E, Modi+ (and Modi 3E predecessor to Modi+) you can get away with thinner DC power conductors in the USB cable by using the supplied AC adapter "wall wart" and matching short USB cable into the second port on the Modi+/Modius E.

If running longer lengths on Bifrost and Modi+, Modius E without wall-wart power supply attached to DAC's power port, look for USB 2.0 or 3.x rated cables with thicker (lower AWG or gauge) power conductors (e.g. 20 AWG is thicker than 22 AWG is thicker than 24 AWG etc.) Generally, USB cables with 20 AWG or thicker power conductors are difficult to find.

I have a 12ft (~4m) USB2.0 cable into Bifrost Multibit OG with Unison upgrade-- that cable is specified with "28 AWG/tp + 20 AWG/2C" where the 28AWG is the Twisted Pair USB signal lines, and 20 AWG wires are the two DC power conductors. Haven't tested a 22AWG version, but I suspect it should work OK. If not, best solution would be to re-arrange things so that a shorter USB cable can be used.

Thank you so much, morpheus69 and tincanear.

 

[emorrison33]

Thank you so much, morpheus69 and tincanear.

I bought this cable, and have had no issues going from my DAP to my Bifrost 2/64.
https://www.amazon.com/dp/B072HGMYMD?psc=1&ref=ppx_yo2ov_dt_b_product_details
Cable For Less makes a longer one too that has been recommended by a few people on Head-fi. I believe this is the company that fellow Head-Fier @Paladin79 used to work for, now retired. He knows his stuff, so I wouldn't hesitate to purchase something he recommends.

 

[FellowTraveller]

I bought this cable, and have had no issues going from my DAP to my Bifrost 2/64.
https://www.amazon.com/dp/B072HGMYMD?psc=1&ref=ppx_yo2ov_dt_b_product_details
Cable For Less makes a longer one too that has been recommended by a few people on Head-fi. I believe this is the company that fellow Head-Fier @Paladin79 used to work for, now retired. He knows his stuff, so I wouldn't hesitate to purchase something he recommends.

Thank you emorrison33 for this suggestion. It's nice to get specific cable recommendations. And this one is surprisingly cheap.

 

[Paladin79]

Thank you emorrison33 for this suggestion. It's nice to get specific cable recommendations. And this one is surprisingly cheap.

My people built plenty of USB cables using 22 AWG cable, I have a Bifrost 2 as well as a Gungnir and I achieved lengths of 16-18 feet with no issues. Mind you I built my own and they were not used for mass sales. The Chinese manufacture plenty of them using low gauge wire and improper shielding thus warnings were in place in the event a customer used one of those.

 

[axle_69]

I ordered my Bifrost 2/64 from Schiit Europe (Sonority Audio) and I like the sound but I can hear transformer hum (and feel the chassis vibrating) even if I unplug all the cables. I did a test with another person and she can notice the difference between being turned on or off up to 1.5 m (5 ft) away. The Yggdrasil, Violectric and Stax amplifiers, etc. are completely silent a few cm away. I'm going to test the Bifrost at the office but if it does the same I will return it, the hum is too annoying, it's a pity because the sound is really good.

I would like to ask Bifrost owners what's the distance from where they stop hearing transformer hum (or can't tell if the unit is turned on or off). I don't think this is normal and the unit is probably defective, but if it is normal hum I will have to find some other DAC.

 

[Mike Foley]

Mine is a BF2, with Saga stacked on top, and I hear no hum.

 

[Lokust]

That "sounds" like a defective DAC.

 

[tafens]

I would like to ask Bifrost owners what's the distance from where they stop hearing transformer hum (or can't tell if the unit is turned on or off). I don't think this is normal and the unit is probably defective, but if it is normal hum I will have to find some other DAC.

There is a lot of variation in transformers, and sometimes hum can resonate or be amplified acoustically depending on placement of the unit physically. Try to add some soft/rubber material under the built-in feet or move it to another location.

To answer the question at hand though, I have had my Bifrost2 (OG) stacked below my Lyr3 for years with no audible hum left about a foot away, both units turned on. I almost never turn the BF off, but when I do, I have noticed that the physical hum is louder the first minute or two and then settles down.

 

[Dr. Cube]

I would like to ask Bifrost owners what's the distance from where they stop hearing transformer hum (or can't tell if the unit is turned on or off). I don't think this is normal and the unit is probably defective, but if it is normal hum I will have to find some other DAC.

I have a 2, not a 2/64 (and the 115 V model, not the 230 V), but the transformer hum is audible on mine only from about 8 cm and closer.

 

[emorrison33]

I ordered my Bifrost 2/64 from Schiit Europe (Sonority Audio) and I like the sound but I can hear transformer hum (and feel the chassis vibrating) even if I unplug all the cables. I did a test with another person and she can notice the difference between being turned on or off up to 1.5 m (5 ft) away. The Yggdrasil, Violectric and Stax amplifiers, etc. are completely silent a few cm away. I'm going to test the Bifrost at the office but if it does the same I will return it, the hum is too annoying, it's a pity because the sound is really good.

I would like to ask Bifrost owners what's the distance from where they stop hearing transformer hum (or can't tell if the unit is turned on or off). I don't think this is normal and the unit is probably defective, but if it is normal hum I will have to find some other DAC.

I don't recall every hearing a hum coming from my Bifrost 2/64. It is the 115vac version though. I currently have it stacked under a Lokius and have had it under Jot 2 and an Asgard 3 at times too. no hum, or at least nothing I ever noticed.

 

[Dr. Cube]

I don't recall every hearing a hum coming from my Bifrost 2/64. It is the 115vac version though. I currently have it stacked under a Lokius and have had it under Jot 2 and an Asgard 3 at times too. no hum, or at least nothing I ever noticed.

I'd never heard it either, until this question prompted me to unstack the Lyr+ from on top of it and then lean down toward it to see if I could hear it. I think that if there's a hum from 1.5 m away then that's way too loud.

 

[emorrison33]

I'd never heard it either, until this question prompted me to unstack the Lyr+ from on top of it and then lean down toward it to see if I could hear it. I think that if there's a hum from 1.5 m away then that's way too loud.

I just tested myself. I actually pulled it out of the rack so I could get a good listen. I don't hear a hum. It's been on for over 2 weeks now. I don't typically turn it off. Take this with a grain of salt. My ears are 53 years old and I can't hear much over 16 kHz.

 

[Rattle]

I've had my OG BF2 for 3 years and it's never made a hum or transformer noise. I have heard the transformers can be noiser when set up for 220/230 or whatever it is on the other side of the pond... I kind of want pimped RCAs on all my schiit dacs now. Thanks @Voxata

 

[Voxata]

I've had my OG BF2 for 3 years and it's never made a hum or transformer noise. I have heard the transformers can be noiser when set up for 220/230 or whatever it is on the other side of the pond... I kind of want pimped RCAs on all my schiit dacs now. Thanks @Voxata

No sweat! Thanks to all those who reached out to have this mod done as well. Parts cost + a few beers and you too can be rid of those crappy tin RCA connectors.

 

[FellowTraveller]

I don't recall every hearing a hum coming from my Bifrost 2/64. It is the 115vac version though. I currently have it stacked under a Lokius and have had it under Jot 2 and an Asgard 3 at times too. no hum, or at least nothing I ever noticed.

I've had a Bifrost 2 for several years, and now a BF2/64 for about six months. I use a 220 V model, and I have not heard any hum. I turn it on in the morning and leave it on all day. It's right under my computer/teaching studio desk. I think if you're hearing a hum 1.5 meters away it suggests a defective unit. Sorry you've had to encounter that.