Geek Pulse: Geek desktop DAC/AMP by Light Harmonics

[marflao]

Unbelievable... so much to "first come, first serve".

 

[earfonia]

FYI, below is measurement of my Geek Pulse XFi headphone output, comparing different digital filters.

Geek Pulse XFi Firmware Version:
Main: 3.0
MCU: 2.4

Measurement equipment: QuantAsylum QA401 Audio Analyzer @ 24/192 mode.
Load on headphone output: 33 ohms.
Output level: 500 mV

Playback of 300 Hz Square wave, 24 bit - 48 kHz flac file generated by Audacity:

FTM (Femto Time Mode):

TCM (Time Coherence Mode):

FRM (Frequency Response Mode):

SSM (Stable Streaming Mode):

Playback of 300 Hz Square wave, 24 bit - 96 kHz flac file generated by Audacity:

FTM (Femto Time Mode):

TCM (Time Coherence Mode):

FRM (Frequency Response Mode):

SSM (Stable Streaming Mode):

 

[miceblue]

What exactly are we looking at here? You're inputting a 300 Hz square wave, yet you're measuring signals up to 75 kHz, and your THD+N measurement is over 48%.

 

[earfonia]

What exactly are we looking at here? You're inputting a 300 Hz square wave, yet you're measuring signals up to 75 kHz, and your THD+N measurement is over 48%.

Square wave measurement is not about THD+N. Digital Filters observation is about how the digital filter cut off the high frequency. So what you see is the characteristic of the low pass filters. Easier to use square wave since square wave has infinite harmonic frequencies, so we can see where it starts to roll off. Different filter different roll off characteristic.

Similar to this observation:

https://www.head-fi.org/f/threads/ifi-micro-idsd-black-label-in-depth-review.833933/#post-13221621

 

[miceblue]

Square wave measurement is not about THD+N. Digital Filters observation is about how the digital filter cut off the high frequency. So what you see is the characteristic of the low pass filters. Easier to use square wave since square wave has infinite harmonic frequencies, so we can see where it starts to roll off. Different filter different roll off characteristic.

Similar to this observation:

https://www.head-fi.org/f/threads/ifi-micro-idsd-black-label-in-depth-review.833933/#post-13221621

Hm I see. I guess I'm just used to seeing the white noise measurement like what Stereophile does, and it makes more sense intuitively. White noise is the same power at all frequencies and when played back, you should see the flat line get chopped off at the Nyquist frequency, depending on the filter.

atomicbob, who I'm sure you're familiar with, did such a measurement for my Pulse X Infinity using his PrismSound dScope III.

RCA -0 dB FS output with the FTM filter using a 24-bit, 44.1 kHz white noise USB input signal

 

[earfonia]

Square wave measurement is not about THD+N. Digital Filters observation is about how the digital filter cut off the high frequency. So what you see is the characteristic of the low pass filters. Easier to use square wave since square wave has infinite harmonic frequencies, so we can see where it starts to roll off. Different filter different roll off characteristic.

Similar to this observation:

https://www.head-fi.org/f/threads/ifi-micro-idsd-black-label-in-depth-review.833933/#post-13221621

Yes similar observation. The reason i use square wave is to observe the pre and post ringing as well, and try to see the correlation between the frequency roll off, sharp or slow, and the pre and post ringing characteristic. Besides that, with square wave, sometime i see the even order harmonic distortion that is not suppose to exist for square wave, as it only has odd order harmonics. So another thing that can be observed besides the roll off characteristic.

 

[rickyleelee]

I backed Geek Pulse October 29 2013 just seven hours after Geek Pulse Campaign start.

LH Labs is aware of me.

Pulse Tickets to LH Labs with shipping estimation from LH Labs

Sun, 13 Dec, 2015 [Current shipping estimation for all 2013 backers is by the end of Dec]
Tue, 29 Mar, 2016 [Current estimations in regard to your date of purchase is W4 April 2016]
Tue, 10 May, 2016 [Current shipping estimation is W1 June 2016]
Thu, 9 Jun, 2016 [Current shipping estimation is W2 July 2016]
Tue, 5 Jul, 2016 [Current shipping estimation is end of July 2016]
Tue, 26 Jul, 2016 [You will receive a shipping notification within the next week]
Tue, 16 Aug, 2016 [Current shipping estimation is by the middle of September]
Fri, 9 Dec, 2016 [Current shipping estimation mid to end of March]
Sun, 5 Mar at 9:02 [Current shipping estimation by the end of March and first in the queue]
Thu, 4 May [Still waiting for reply]

 

[rickyleelee]

Was at the recent Shanghai Show a few weeks ago. Larry Ho was there marketing a new DAC. About $6k price point. I don't go to the US much, does Larry Ho go to any more USA show? i don't even see LH advertising anywhere like here on head fi. i might have missed with the new head fi web platform. To me he should have delivered on the crowd funding guys by now. it has been quite a lot of months. my partner who controls the purse did not let me crowd fund as I nearly droppped $2k into larry's pocket.

 

[doctorjazz]

What was the DAC called if you recall, @rickyleelee? Aside from the Pulse, there is also a crowdfunded Vi DAC that some of us are waiting for. Could they really be starting up on a 3rd crowdfunded DAC without supporters receiving the previous items?

 

[MikeyFresh]

What was the DAC called if you recall, @rickyleelee? Aside from the Pulse, there is also a crowdfunded Vi DAC that some of us are waiting for. Could they really be starting up on a 3rd crowdfunded DAC without supporters receiving the previous items?

Don't forget they had already some time ago announced a new DAC called Sire, though they never at any point suggested that one would be crowd funded.

Does anyone remember whether or not Sire was supposed to be at the $6k price point mentioned in Post #12383?

@rickyleelee do you recall if it was Sire DAC, and can you clarify whether or not LH Labs was trying to crowd fund this new DAC, or simply showing it in Shanghai?

Thanks.

 

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

On the middle stages of the Geek Pulse campaign. Larry was talking of a possible baby DaVinci.Maybe this is it?

 

[germay0653]

The Sire was to replace the Da Vinci itself at >= $120,000.00 and definitely was not the baby Da Vinci. The Sire had a full page advertisement in TAS (see below).
Unfortunately, I don't think it will see the light of day, at least for the foreseeable future.

 

[graham508]

I'm still waiting for my Infinity, ordered Oct 2013
and my LPS, ordered Dec 2013

 

[rickyleelee]

Wasn't the sire as it was not $120,000. Just $6,000. I can't remember the name only it was red like blood red so caught the eye

 

[doctorjazz]

Only in the audiophile world would the description for a DAC be, "it's only $6000..."