[FredA]

Ok so I did actually test it this time, got down to the bottom shelf, and yes there is a hum.

But I never noticed it before and I sit right next to my gear. Have to put my ear right up to the vent.

This is a guy who has returned many a noisy hard drive and has laboured diligently for a silent PC.

So far, as far as i know, they all hum a bit. The big transformer works hard. It does not affect the perf...

 

[FredA]

Quick question for anybody that has a DI-20HE, maybe you could test this for me.
Want to know if this is normal, or if I need to send my 20HE back to Kingwa for a look over.

I have the US 120v version, and after about 2-3 minutes of being on, it has coil wine (assuming from the class A transformer setup).
It's not that loud, but in a dead quiet room, can be slightly audible from as far as 6ft away.

If anybody tests their own unit for me, just put your ear close to one of the vents top or bottom, should be easily audible.

Thanks!

Is it a plain hum or something with a modulation?

 

[comzee]

Ok so I did actually test it this time, got down to the bottom shelf, and yes there is a hum.

But I never noticed it before and I sit right next to my gear. Have to put my ear right up to the vent.

This is a guy who has returned many a noisy hard drive and has laboured diligently for a silent PC.

Same here on silent PC and stuff like that. I just recently moved. At my new place, it's all hardwood floors, and the way I have it setup, was on the floor, kinda like 4-5ft away from my ears (hardwood floor reflects sound like a mofo). I did this because I like to run ultra short HDMI for i2s, and it's my HP rig near my bedside. From what you and FredA are saying, the hum I get is completely normal. As I said, it's very feint.

Literally anything going on in my room, can't hear it. But if it's a dead silent night, furnace isn't running, I can hear it just a bit.

Is it a plain hum or something with a modulation?

Nah, just transformer hum, like you mentioned in your related post: "So far, as far as i know, they all hum a bit. The big transformer works hard."

This eases my mind, thanks for the input guys. I actually don't mind the hum, I can easily re-situate my audio gear to accommodate it being a bit further from my bedside table.
I more wanted to know if it was normal, and now I know it is.

Thanks!!

P.S. I'm still going to post my DDC roundup review, but it's actually hard to a/b DDC over and over (when you have 6 to a/b), and with moving and general life, it's been a bit delayed.

 

[PeterCraig]

I also use some high tech vibration isolators under the DI20HE. In the form of white draftsman erasers haha.

I'm more head fi not too worried about vibration from my desk top speakers.

I don't know if they assist with the hum but I think any type of isolation may help.

 

[Zachik]

P.S. I'm still going to post my DDC roundup review, but it's actually hard to a/b DDC over and over (when you have 6 to a/b), and with moving and general life, it's been a bit delayed.

Which DDC are you going to (or already have) A/B?

 

[DecentLevi]

There's some secret sauce to my chain that solves many issues that other products can't.

Usb purifier reclocks the zen stream then sends it to the cosemi optical cable. Cosemi then transcodes it from electrical to optical. Tail end of cosemi transcodes it from optical to electrical + some reclocking. Then purifier reclocks that for good measure then sends it to the dac. The idefender gives the purifier an edge via multi stage filtering. The 2 purifiers and the cosemi has a clock and clock performance is super sensitive to load stability and mechanical vibration. Bonus performance is the optical fiber for the data lanes on the cosemi cable. I can't take one component out. I've been spoiled by it. This makes my chain very sensitive too actually to a level of 'everything matters'. I wanna still put a ddc after that so I can use optical but I lack a multi stage power supply for such.

Very nice! At first glance it sounded like an excessively long signal path with too many optical to electrical conversions, but not so much after I visualize it. You're like me, I'm more in the camp that multiple USB purifiers/reclockers, etc CAN Make a difference, and a longer signal path doesn't always mean loss. (Analog only signals are another story, mind you).

If I'm not mistaken, it looks like you're above mentioned setup isn't all that expensive, right? I saw Cosemi USB optical cables for as low as $40... Or am I looking at the wrong model? Also those don't seem to have an independent DC side connection, like the Monoprice USB optical cable does, so wondering if maybe that would put the performance at a lower tier than those?

For purifiers, you mentioned Idefender at the receiving side, but mind to tell me which the other one is you're using at the PC side?

Looks like you're on a good path man! I definitely recommend adding a DDC like DI-20, or maybe Singxer SU-6. My opinion is that not only do DDC's make a big difference on a highly resolving system, but you can really gain stages of improved fidelity even more so with adding both digital purifiers and clean power to it. Not so sure how necessary multi-stage power filtering is, but I've got one single hefty 100-lb filter with eight outlets that I use for my whole system, and at least with shielded thick cables it does the job very well indeed. And almost certainly you well find another combination of purifiers or even normal USB cables, after getting the DDC.

 

[801evan]

Very nice! At first glance it sounded like an excessively long signal path with too many optical to electrical conversions, but not so much after I visualize it. You're like me, I'm more in the camp that multiple USB purifiers/reclockers, etc CAN Make a difference, and a longer signal path doesn't always mean loss. (Analog only signals are another story, mind you).

If I'm not mistaken, it looks like you're above mentioned setup isn't all that expensive, right? I saw Cosemi USB optical cables for as low as $40... Or am I looking at the wrong model? Also those don't seem to have an independent DC side connection, like the Monoprice USB optical cable do, so wondering if maybe that would put the performance at a lower tier than those?

For purifiers, you mentioned Idefender at the receiving side, but mine to tell me which the other one is you're using at the PC side?

Looks like you're on a good path man! I definitely recommend adding a DDC like DI-20, or maybe Singxer SU-6. My opinion is that not only do DDC's make a big difference on a highly resolving system, but you can really gain stages of improved fidelity even more so with adding both digital purifiers and clean power to it. Not so sure how necessary multi-stage power filtering is, but I've got one hefty 100-lb filter with eight outlets that I use for my whole system, and at least with shielded thick cables it does the job very well indeed.

Cosemi runs cool and you can ask for custom 1m /1.5m. shortest monoprice is 10m. The longer copper lines affect sq. You must have it unfurled and not coiled. Cosemi is around 60-100usd.usb 3 AOC. Not the extender one. I make my own couplers using silver occ. Previously I was using Uptone.

I use idefender on both upstream and downstream. Multi stage filtering to power them is a must. And I have dedicated line conditioners on top of that.

All this is the USB chain and still necessary before putting a ddc afterwards. I need a ddc because the Soekris DAC USB is horrible and will only use vbus if I'm on usb in. External power 5v (multi-stage filtering) + toslink is TOTL dac quality.

So far even using a silly topping d10s maintains the USB quality I hear. Though it's a bit edge and thin but the blacks and soundstage is the same. I can't say the same with matrix Xspdif2. I'm still trying to build a src dx cable where I don't need to use adapters. After that, I'll see how the di-20he fares.

 

[sajunky]

Nah, just transformer hum, like you mentioned in your related post: "So far, as far as i know, they all hum a bit. The big transformer works hard."

In this case it is not that a transformer works very hard, it is magnetic field magnetostriction effect (periodic expanding/contracting of the core). Hum is getting louder when a mains voltage increase close to the saturation point and a load is low. If you have power generator, you can adjust voltage to see whether it lowers a noise.

R-Core transformers generate little noise. In many cases we hear not a vibration of the core, but but interaction with the assembly point. In this case tightening a screw will help, there should be four screws mounting the transformer, two of them are marked on the photo with arrows.

 

[FredA]

In this case it is not that a transformer works very hard, it is magnetic field magnetostriction effect (periodic expanding/contracting of the core). Hum is getting louder when a mains voltage increase close to the saturation point and a load is low. If you have power generator, you can adjust voltage to see whether it lowers a noise.

R-Core transformers generate little noise. In many cases we hear not a vibration of the core, but but interaction with the assembly point. In this case tightening a screw will help, there should be four screws mounting the transformer, two of them are marked on the photo with arrows.

Not easy to cure in this case. Anyway, it's feint.

 

[801evan]

There's the ifi dc blocker that fixes tranformer hum.

 

[DecentLevi]

Cosemi runs cool and you can ask for custom 1m /1.5m. shortest monoprice is 10m. The longer copper lines affect sq. You must have it unfurled and not coiled. Cosemi is around 60-100usd.usb 3 AOC. Not the extender one. I make my own couplers using silver occ. Previously I was using Uptone.

I use idefender on both upstream and downstream. Multi stage filtering to power them is a must. And I have dedicated line conditioners on top of that.

All this is the USB chain and still necessary before putting a ddc afterwards. I need a ddc because the Soekris DAC USB is horrible and will only use vbus if I'm on usb in. External power 5v (multi-stage filtering) + toslink is TOTL dac quality.

So far even using a silly topping d10s maintains the USB quality I hear. Though it's a bit edge and thin but the blacks and soundstage is the same. I can't say the same with matrix Xspdif2. I'm still trying to build a src dx cable where I don't need to use adapters. After that, I'll see how the di-20he fares.

Interesting and educational, thank you. Admittedly this brings up many questions, so feel free to reply by PM., but maybe it's better to post here for our knowledge too...

Wow, the shortest Monoprice optical USB cable is 30 ft? No thanks for me. What were you referring to by the longer copper lines affecting sound quality - I thought we were talking about optical cables. What were you referring to by "extender ones"? And what were you trying to by "couplers"?

The Cosemi USB optical cable with a USB purifier on both ends does sound like a good alternative to a Monoprice cable with clean DC power into it. And curious, have you compared it to any other USB optical cables, or how does it fare against regular USB cables sound-wise?

Did you mean you are powering the Idefenders externally? Maybe with a hack of some kind because it doesn't seem to have a dedicated power connection.

Keep me in the loop about your journey on this, and I'll post here too once I eventually get my DDC chain sorted out.

 

[801evan]

Interesting and educational, thank you. Admittedly this brings up many questions, so feel free to reply by PM., but maybe it's better to post here for our knowledge too...

Wow, the shortest Monoprice optical USB cable is 30 ft? No thanks for me. What were you referring to by the longer copper lines affecting sound quality - I thought we were talking about optical cables. What were you referring to by "extender ones"? And what were you trying to by "couplers"?

The Cosemi USB optical cable with a USB purifier on both ends does sound like a good alternative to a Monoprice cable with clean DC power into it. And curious, have you compared it to any other USB optical cables, or how does it fare against regular USB cables sound-wise?

Did you mean you are powering the Idefenders externally? Maybe with a hack of some kind because it doesn't seem to have a dedicated power connection.

Keep me in the loop about your journey on this, and I'll post here too once I eventually get my DDC chain sorted out.

Usb Optical cables are optical on the data lines. But for convenience, the power and ground is copper lines. These are primarily designed for a office printer that's in the next room and hasn't discovered network printing yet.

Man, I've tried 3 or 4 brands. The OG is the Corning optical cable. It was the best AND usb 2.0 compatible. Monoprice is actually hit or miss sometimes with DACs. Thing is it runs hot. It does 15v in the vbus and that's why I've gone through 5 of them. And u was paying premium for used ones coz it's a dead product but....it was worth it? And no competition. I even modded it where I cut the power and ground and did a power bypass on the tail end. It was glorious!!! But that only lasted a few months. I couldn't do it on the monoprice and the cosemi....it can work on flash drives but not on DACs. So sad.

With 33feet/10m being the shortest for monoprice, one would likely have it coiled. So this actually affects the sound as it will have a induction effect. So I have it unfurled...but then that'll give an antenna effect. I have it stretched out like Christmas lights clinging to the wall...still better sounding than coiled. Then finally a couple years later I discovered cosemi and it was 1.5m on Amazon. That got sold out fast. So hitting their website, I got 1m. But the website is dead now. Cosemi is 5v on the copper lines...no idea how they did it. Both monoprice and corning is 15v and runs cool. Maybe the longer cables are set on a higher voltage. Oh and as proof of concept, when I modded the corning with the power bypass trick, I can keep the 30ft cable coiled. Lol.

Oh, I tried powering that monoprice optical cable... Adding idefender and powering that is still much better. Exactly why Im sticking to it even if I have a ddc. Idefender give you the ability to do power bypass via USB c. So I have custom dc to usb c cables for it and using multi stage filtering to power it. That makes a difference AND transport quality still makes a difference. That's the whole point. These are all still necessary and a prep to make the task easier for the ddc.

 

[DecentLevi]

Also has anyone here compared this to the Gustard U18? Looks like that just came out last year. It's the upgrade to their U16 and looks like a DI-20 HE replacement, not to mention half the price.

 

[gimmeheadroom]

Also has anyone here compared this to the Gustard U18? Looks like that just came out last year. It's the upgrade to their U16 and looks like a DI-20 HE replacement, not to mention half the price.

I have never seen anything from Audio-gd that isn't a top value. If something is half the price, I bet 100 bucks it's not a replacement

 

[Articnoise]

I have never seen anything from Audio-gd that isn't a top value. If something is half the price, I bet 100 bucks it's not a replacement

Synergy and preference are important aspects when it comes to summit hifi.