[eliwankenobi]

Also, Larry is optimizing both 1/4" and balanced output with different components. So its not like they are just taking the positive leads and ground and called it a day

 

[m-i-c-k-e-y]

Just a follow up on my post on: http://www.head-fi.org/t/687851/geek-pulse-geek-desktop-dac-amp-by-light-harmonics/1590#post_10499712
Regarding on Larry's weekend listen on Pulse/Pulse X with Femto.
 
There were questions after, was there Mu shielding, filter used, opamp used etc.
 
So here are other parameters during that event
 

Larry Ho Moderator OFFLINE Karma: 42

Good questions: 1. Mu metal shield? Not yet... They are making it. Well... Since I'm EE, I always said: Why you ME guys are so slow? LOL... And I got some rolling eyes. 2. This is ESS Linear Filter. So with M.P filter, it will be even better!  3. LME49990 and OPA1612 in this configuration. From the feedbacks of the Geek Out first time users, most of them express the excitement of sound for its wide, expanded sound stage, natural and extended highs and very dark background. We heard the same feedbacks three years ago, when a lot of senior audiophile listen to our Da Vinci DAC debut in Axpona. I'm glad to know that we could achieve a relatively consistent Light Harmonic House sound from products to products. Geek Pulse with Femto.... Let's wait and see. Larry

 

[Muinarc]

Nice stuff. What is the "M.P filter" he mentions? I don't know much about filters, just what they do/how they work.

 

[junker]

Nice stuff. What is the "M.P filter" he mentions? I don't know much about filters, just what they do/how they work.

Minimum phase. Steep filters "ring" when there is an impulse signal like a sharp spike. Real world things ring all the time after an event... think a drum whack as it decays or a piano note as it hangs.
 
The problem is with a normal "linear" filter is that the ringing happens before and after the event. A decaying tail isn't that big of a deal, but the pre-ring sounds really weird and unnatural. The minimum phase filter shifts the pre-ring over to the post ring. And there are other considerations as well so as to not make the tail longer than necessary.
 
With normal 44.1HKz material that is when the slope is crazy steep, but with higher res material gentler filters can be used. With, 44.1 KHz the slope (steepness) of the digital filter can be relaxed a little and started a bit earlier to really knock down the ringing. This usually sounds a lot more natural if you don't mind losing a dB or so at the very, very top. ESS has a fast and slow linear filter baked-in but no minimum phase filter. 
 
This is the Ayre paper on their filter that is a pretty good primer:
 
http://www.ayre.com/pdf/Ayre_MP_White_Paper.pdf
 
Cheers.

 

[Muinarc]

Ah got it, I've actually read that Ayre paper before but I will probably re-read it later so thanks for posting it!

 

[Muinarc]

Received the campaign update last night, saw that the Pulse front panel is due in soon? I'd love to see pictures of that when it's in!

 

[eliwankenobi]

Yeah! We all are!!

 

[Muinarc]

Almost slipped off the front page of this forum section, we can't have that!

I was looking into the Mu metal shields, are there any DACs using this that anyone knows about? Thought I'd do some more reading on the subject.

 

[junker]

Almost slipped off the front page of this forum section, we can't have that!

I was looking into the Mu metal shields, are there any DACs using this that anyone knows about? Thought I'd do some more reading on the subject.

MSB Diamond
 

 

[Muinarc]

MSB Diamond
 

 


Thank you for that. Looking at a review; "MSB upgraded this model with these options: FemtoSecond Galaxy Clock ($9950)..." I'm into HiFi so the $20+ thousand dollar price tag doesn't surprise me, but $10k just for that option, hah.

 

[eliwankenobi]

speaking of which,
 
I think we are due for a PCB picture aren't we?

 

[Larry Ho]

  speaking of which,
 
I think we are due for a PCB picture aren't we?

 
Waiting for that mu metal shielding... Gee... We need a high precision one, and that vendor failed us two times.
 
Hope we could get it right in third times.
 
Larry

 

[eliwankenobi]

Waiting for that mu metal shielding... Gee... We need a high precision one, and that vendor failed us two times.

Hope we could get it right in third times.

Larry

Third time is the charm!

 

[m-i-c-k-e-y]

No it its not Pulse....Hoping!!
 

 

[germay0653]

I think I see 5.1 SE outputs there!!