[ToTo Man]

  Yep...I think there are two options here.  
 
1)  Your system isn't going to pick up the differences and a MB isn't going to do much to change that.  So, you can either chill with the 4490 and be happy or plan to spend significantly more money to find something that will have a real impact.  And even if you do spend a ton of money, it's still no guarantee...
 
2)  You're a little bit DAC-deaf.  This would be FANTASTIC news.  Spare your wallet, sit back, and enjoy the tunes.  

 
Quite possibly, yes.   Although I do remember it was much easier to hear the improvement going from the original Bifrost to the Bifrost Uber.  The Uber sounded like a veil had been lifted and everything was clearer and more dynamic.  The difference between the Uber and 4490 is more subtle IMO, but the 4490 is slightly more dynamic and 3D, particularly in the mids.  It might even be a tiny bit bubblier/livelier than the Uber, it's certainly not smoother.  
 
I am still unable to get hold of a Bimby or Yggy to hear in my system, but will be playing with a Gungnir MB this weekend which will give me a flavour of MB.  It will also allow me to test the balanced inputs on my A-S3000 and see if this elevates the sonic performance (it did when I heard Gumby with Mjolnir2 last year), but I'm getting a bit off topic here.  
 
I still think I'll probably end up executing my original plan; buy an Yggy for my main system and upgrade my Uber to 4490 for a second system.  From the comments here I don't think Bimby will give me the detail retrieval I crave, and if I'm going to splurge the cash on a Gumby then I figure I might as well get the Yggy and step-off the upgrade ladder (for a while at least!).

 

[skyline315]

   
Quite possibly, yes.   Although I do remember it was much easier to hear the improvement going from the original Bifrost to the Bifrost Uber.  The Uber sounded like a veil had been lifted and everything was clearer and more dynamic.  

 
Funny.  
 
That's exactly how I felt about the move from the Uber to the 4490

 

[ColtMrFire]

Before I got the 4490 most reports I read said it was a pretty obvious and substantial upgrade from the Uber. Having never heard the Uber though, I cant comment further.

 

[520RanchBro]

Before I got the 4490 most reports I read said it was a pretty obvious and substantial upgrade from the Uber. Having never heard the Uber though, I cant comment further.

I think there's a tendency to exaggerate improvements in this hobby too, I'm curious to compare it to my Modi 2U and see the improvements. I'm a bit more skeptical about the magnitude of improvements than most. I do honestly believe the Bifrost will at least be noticeably better, but not by 50% or anything, we're talking smaller margins here mostly. Then again, I could just be blown away and I hope that's what happens.

 

[ColtMrFire]

I had the Modi 2 (non uber) before the 4490. Fairly night/day difference IMO. And the Modi 2 is a very good DAC.

 

[520RanchBro]

I had the Modi 2 (non uber) before the 4490. Fairly night/day difference IMO. And the Modi 2 is a very good DAC.

You're making the wait even harder! 
 
Should be here tomorrow though!

 

[theveterans]

I think there's a tendency to exaggerate improvements in this hobby too, I'm curious to compare it to my Modi 2U and see the improvements. I'm a bit more skeptical about the magnitude of improvements than most. I do honestly believe the Bifrost will at least be noticeably better, but not by 50% or anything, we're talking smaller margins here mostly. Then again, I could just be blown away and I hope that's what happens.

YMMV as always, but 4490 should give an overall deeper presentation.

 

[520RanchBro]

YMMV as always, but 4490 should give an overall deeper presentation.

That's what I'm looking for now that I have the HE-560, great separation and soundstage but depth seemed a tad shallow in my current setup. This is all very encouraging.

 

[DeadHead57]

You're making the wait even harder! 

Should be here tomorrow though!

I also had the Modi but mine was the uber model. Trust me you will be quite happy with the 4490. The Bifrost is much more musical and refined. IMO.

 

[ToTo Man]

I currently have 4490 and Gumby demo units in my possession (I still can't lay my hands on Bimby and Yggy) and I've just spent an interested evening comparing them.  Being demo units, both DACs are assumed to be burned in, however I only gave Gumby 3hrs warm up time, so I'll happily revise my findings if its sonic character develops further over the coming days.  The following impressions were formed using my main system with loudspeakers and not my headphone rig.  4490 connected to my A-S3000 single-ended, and Gumby connected to my A-S3000 both single-ended and balanced.
 
Caveat: 
In my system all three DAC outputs differ in level, confirmed by the watt/VU meters on my A-S3000.  The difference is very small, but audible nevertheless.  The single-ended 4490 is the loudest, followed by the balanced Gumby (my A-S3000 automatically attenuates balanced input signals down to normal line levels), and the single-ended Gumby is the quietest.  It's impossible to objectively evaluate DACs unless the output level is equal, so I tried as best I could to equalise levels further when switching between them.  
 
Comparison - 4490 single-ended vs Gumby single-ended:
Gumby sounds smoother and more relaxed and natural than 4490.  It's not any less detailed or duller - in fact I was pleased to discover Gumby still has nice crisp highs - but everything seems more grounded and focused.  Instrument locations are easier to pinpoint, and transients are cleaner and shorter.  Gumby's overall presentation is smaller in size.  4490 sounds larger, more floaty and more dazzling, but it also sounds more 'digital' (strained/strident/etched) during busy passages.  4490 has some kind of digital 'ringing' or 'haloing' going on that I didn't notice until hearing Gumby, a bit like a 'hall' ambience/reverb effect.  In simple terms, Gumby sounds like the positive effect you get from adding some acoustic absorption panels to your room.

 

[skyline315]

   4490 has some kind of digital 'ringing' or 'haloing' going on that I didn't notice until hearing Gumby, a bit like a 'hall' ambience/reverb effect. 

 
The Uptone Regen makes a difference on this front when paired with the 4490.

 

[520RanchBro]

Yep this, improvement is quite noticeable. I've got a towering Schiit stack now, I'll have to take some photos once I finish tidying up my desk. The Bifrost 4490 is a very worthy upgrade!

 

[520RanchBro]

I'm definitely hearing the increase in depth, feels like the music just has more weight to it in general. No real change to frequency response which is good, just more of everything 

 

[ColtMrFire]

The Uptone Regen makes a difference on this front when paired with the 4490.

Good cause my regen amber arrives in a few days!

I already have two jitterbugs and they add more depth and dimensionality to the 4490. I hear adding a regen gives even further improvement.

I also recently added a power conditioner and that did incredible things for the bass (much deeper, fuller and more natural) and some added clarity.

 

[ToTo Man]

Good cause my regen amber arrives in a few days!

I already have two jitterbugs and they add more depth and dimensionality to the 4490. I hear adding a regen gives even further improvement.

I also recently added a power conditioner and that did incredible things for the bass (much deeper, fuller and more natural) and some added clarity.

 
I've never heard a USB decrappifier but I am intrigued because from the comments of many on this forum they do seem to work.  I think I might buy a Wyrd and hear what all the fuss is about. 
 
I'm a bit concerned about the need to 'daisy-chain' decrappifiers together though.  Surely if a decrappifier does the job it's supposed to, you only need one of them before your DAC, not a bunch of them?!