[johnreekie]

If you don't mind my saying, just let your ears decide. If you don't really understand the technical details, then don't let yourself be misled by them.

 

[Decoy]

Nevermind. 

 

[Maelob]

its been two weeks since i got a shipping notice from LH labs but they still have not shipped the pulse. is that normal? I will give them a couple extra days and open a ticket.  Just curious if anybody else had the same issue. 

 

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

Have you looked at its USPS tracking number?
 
Where you're at? If outside the US, its the local customs who are sometimes the culprit.

 

[earfonia]

  If you don't mind my saying, just let your ears decide. If you don't really understand the technical details, then don't let yourself be misled by them.

 
Agree. How it sounds matter most.
But there is nothing wrong to ask technical question to learn and understand it better, so we don't misled by them.  So, do you have any technical info how's the Pulse volume control works?

 

[SilverTrumpet999]

   
Agree. How it sounds matter most.
But there is nothing wrong to ask technical question to learn and understand it better, so we don't misled by them.  So, do you have any technical info how's the Pulse volume control works?

It's an internal high precision calculation carried out on the input data within the ESS chip. In essence your data is converted to a higher bitrate during the calculation and then that result is what the (32-bit) DAC acts upon. In fact, it's so high precision that there is theoretically no fidelity lost due to the digital attenuation.
 
All the knob controls is the factor which is used in that digital attenuation calculation. When it's at 0dB, the original signal is passed. By definition, it's bypassed at 0dB. Since this all happens in the ESS chip, "bypassing" the calculation doesn't make sense.
 
I'm confident the above is true with a possible caveat for DSD input. Larry or someone from LH with an intimate understanding of that signal path would need to chime in.

 

[earfonia]

  It's an internal high precision calculation carried out on the input data within the ESS chip. In essence your data is converted to a higher bitrate during the calculation and then that result is what the (32-bit) DAC acts upon. In fact, it's so high precision that there is theoretically no fidelity lost due to the digital attenuation.
 
All the knob controls is the factor which is used in that digital attenuation calculation. When it's at 0dB, the original signal is passed. By definition, it's bypassed at 0dB. Since this all happens in the ESS chip, "bypassing" the calculation doesn't make sense.
 
I'm confident the above is true with a possible caveat for DSD input. Larry or someone from LH with an intimate understanding of that signal path would need to chime in.

 
Thanks! No doubt it is precise, and my ears tell me XFi sounds good.
I have no issue with PCM data, just technical curiosity how the DSD signal is processed for volume adjustment.

 

[taz23]

  its been two weeks since i got a shipping notice from LH labs but they still have not shipped the pulse. is that normal? I will give them a couple extra days and open a ticket.  Just curious if anybody else had the same issue. 

My Geek Pulse was picked up by USPS on the day the shipping notice was sent to me.  I would open a ticket if it has not been picked up for the past two weeks based on the tracking.

 

[Maelob]

I will do that, I keep checking USPS tracking number and still shows pre-shipment, something is not right. thanks

 

[johnreekie]

   
Agree. How it sounds matter most.
But there is nothing wrong to ask technical question to learn and understand it better, so we don't misled by them.  So, do you have any technical info how's the Pulse volume control works?

 
Only what LH Labs have publically stated. They've said that at 0 dB the volume control processing is bypassed. But look at it this way (you have a Pulse, right) - does it sound different to you at 0 dB and -0.5 dB?

 

[miceblue]

Just saw this.

[video]https://www.youtube.com/watch?v=Imv5-OhQbZI[/video]


So........does that mean the 4x more expensive Pulse X Infinity units, probably the flagship of the "Geek" products, do not get to pass all of these tests?

Everything goes through AP tests. X Infinity included.

I got my Pulse X Infinity back from the RMA process and I received an Audio Precision test sheet too.
Holy cow that's a lot of tests

Spoiler: List of AP QC Tests

Initial Start

• Starting Prompt - PASSED
• Starting Prompt - PASSED

USB Input - 1/4" HP Out (High)

• Signal Path Setup - PASSED
• Prompt - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• DC Level - PASSED
• Prompt - PASSED

USB Input - 1/4" HP Out (Low)

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• DC Level - PASSED
• Prompt - PASSED

USB Input - Balanced Headphone Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• DC Level - PASSED
• Prompt - PASSED

USB Input - RCA Line Out

• Signal Path Setup - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• Prompt - PASSED

USB Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• Prompt - PASSED

AES Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED
• Prompt - PASSED

SPDIF_1 Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Prompt - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED
• Prompt - PASSED

SPDIF_2 Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED
• Prompt - PASSED

Toslink Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED

Sequence Result:

• Sequence Result - PASSED

 

[chartwell85]

I got my Pulse X Infinity back from the RMA process and I received an Audio Precision test sheet too.
Holy cow that's a lot of tests

Spoiler: List of AP QC Tests

Initial Start

• Starting Prompt - PASSED
• Starting Prompt - PASSED

USB Input - 1/4" HP Out (High)

• Signal Path Setup - PASSED
• Prompt - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• DC Level - PASSED
• Prompt - PASSED

USB Input - 1/4" HP Out (Low)

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• DC Level - PASSED
• Prompt - PASSED

USB Input - Balanced Headphone Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• DC Level - PASSED
• Prompt - PASSED

USB Input - RCA Line Out

• Signal Path Setup - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• Prompt - PASSED

USB Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• IMD (SMPTE) - PASSED
• Signal to Noise Ratio - PASSED
• Crosstalk, Left Channel - PASSED
• Crosstalk, Right Channel - PASSED
• Interchannel Phase - PASSED
• Prompt - PASSED

AES Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED
• Prompt - PASSED

SPDIF_1 Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Prompt - PASSED
• Level and Gain - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED
• Prompt - PASSED

SPDIF_2 Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED
• Prompt - PASSED

Toslink Input - XLR Balanced Out

• Signal Path Setup - PASSED
• Static Noise Level - PASSED
• THD+N - PASSED
• Signal to Noise Ratio - PASSED

Sequence Result:

• Sequence Result - PASSED

Yes. Lots of tests. Glad you posted this

 

[earfonia]

   
Only what LH Labs have publically stated. They've said that at 0 dB the volume control processing is bypassed. But look at it this way (you have a Pulse, right) - does it sound different to you at 0 dB and -0.5 dB?

 
I just received it end of June, so haven't got the time to carefully observe it.
 
You're right, what matters is that it is sound good, and I agree on that. 
 
That's great if at 0 dB both PCM and DSD signal bypass the digital volume control!  I just hope in the future firmware upgrade, they put the option in the menu, to bypass volume control for Line Output, so I don't have to adjust the volume when using external amp. Not sure if it is possible for the Pulse design architecture. My Mytek and Yulong DA8 both have bypass option for Line Out.
 
I'm not concerning the difference of sound quality between -0.5 dB and 0 dB, but just purely technical curiosity how does XFi adjust the volume of DSD signal, I simply just want to know the technical info if anyone here could enlighten me.
 
I've watched this as well, but Martin didn't specifically mentioned the digital volume control for DSD signal, probably the same as PCM, through 32 bit digital volume control:

 

[kenman345]

   
I just received it end of June, so haven't got the time to carefully observe it.
 
You're right, what matters is that it is sound good, and I agree on that. 
 
That's great if at 0 dB both PCM and DSD signal bypass the digital volume control!  I just hope in the future firmware upgrade, they put the option in the menu, to bypass volume control for Line Output, so I don't have to adjust the volume when using external amp. Not sure if it is possible for the Pulse design architecture. My Mytek and Yulong DA8 both have bypass option for Line Out.
 
I'm not concerning the difference of sound quality between -0.5 dB and 0 dB, but just purely technical curiosity how does XFi adjust the volume of DSD signal, I simply just want to know the technical info if anyone here could enlighten me.
 
I've watched this as well, but Martin didn't specifically mentioned the digital volume control for DSD signal, probably the same as PCM, through 32 bit digital volume control:

I am sorry for you, but I doubt you will find such a firmware change. You see, the screen and the board have their own firmware flashed to them. The board is the one that can be user upgraded. The screen firmware must be upgraded at the factory/manufacturer as it requires the unit to be opened. The reason we have some options like SSM in the menu for the Filter Mode is because they needed to have it available for when the board is updated to support that function. This of course will be different in the new Chassis though as they have incorporated an SD Card feature that allows firmware updates to the screen. 
 
I really feel that they should/could offer current Chassis units a upgrade wherein they take the unit back and replace the back plate with a new one that has a spare hole/slot and a cable that connects to the screen on the unit. This way, that hole can be for a microUSB connection, USB A connection, SD Card or even a microSD slot if that made more sense. It would really be nice to have a way to cost effectively give people updates to the screen. Of course, this all depends on how often such an upgrade would need to be performed. I even would be okay with a IR transmitter being recommended and a software tool to send the new firmware through the IR sensor, but I doubt they put something like that in. It could've been really cool to do it that way though questionable about reliability. I remember in college reviewing many methods of over the air error correction that was meant to be used so that radio waves across africa and other segmented/remote settled regions can have items like the One Laptop per child units be updated properly without errors. With so many actual options, it seems a bit like a neglected cause, something they didnt want to delay the product an extra week to accomplish.
 
Do not get me wrong, i am not mad that they didnt do it, but more surprising that they didnt give it much thought in the first round but the second chassis was made bulkier to accomplish this one specific task however rarely that may be.
 
 
Now on to other stuff. My tracking says my 2m Lightspeed 2G is to arrive today. I am very excited. I am thinking I will set up my X Fi in my basement and hook up some headphones (or maybe I'll set it up with my 5.1 Paradigm speaker system for a little fun) and burn in the cable and the X Fi for a few days. Not entirely sure if i'll do that or not but it would be fun

 

[earfonia]

  I am sorry for you, but I doubt you will find such a firmware change. You see, the screen and the board have their own firmware flashed to them. The board is the one that can be user upgraded. The screen firmware must be upgraded at the factory/manufacturer as it requires the unit to be opened. The reason we have some options like SSM in the menu for the Filter Mode is because they needed to have it available for when the board is updated to support that function. This of course will be different in the new Chassis though as they have incorporated an SD Card feature that allows firmware updates to the screen. 
 
I really feel that they should/could offer current Chassis units a upgrade wherein they take the unit back and replace the back plate with a new one that has a spare hole/slot and a cable that connects to the screen on the unit. This way, that hole can be for a microUSB connection, USB A connection, SD Card or even a microSD slot if that made more sense. It would really be nice to have a way to cost effectively give people updates to the screen. Of course, this all depends on how often such an upgrade would need to be performed. I even would be okay with a IR transmitter being recommended and a software tool to send the new firmware through the IR sensor, but I doubt they put something like that in. It could've been really cool to do it that way though questionable about reliability. I remember in college reviewing many methods of over the air error correction that was meant to be used so that radio waves across africa and other segmented/remote settled regions can have items like the One Laptop per child units be updated properly without errors. With so many actual options, it seems a bit like a neglected cause, something they didnt want to delay the product an extra week to accomplish.
 
Do not get me wrong, i am not mad that they didnt do it, but more surprising that they didnt give it much thought in the first round but the second chassis was made bulkier to accomplish this one specific task however rarely that may be.

 
I see. Firmware update seems rather complicated 

 
Anyway, thanks for the info!