[eac3]

So I got around to listening to the Geek Pulse Infinity (with 2G cable and LPS) a little more closely to my Audio-gd NFB-28 (Fall 2013), after burning in the 2G cable for at least another 100+ hours.
 
First of all, it was very hard to distinguish immediately, but nonetheless, there were 1 or two differences I observed. I use Music Bee, and my only headphones at the moment are the Philips Fidelio X1. Last time I compared the two more closely, was through XLR out to my Emotiva amp and Klipsch floorstanding Speakers. These are just my opinions and in no way am I wanting to suggest that this was a very scientific comparison. Also, my head-fi vocabulary is limited and may not make any sense to you. Just thought I would share.
 
Most of the reference music I see in listening impressions and reviews I am not very familiar with. I have included some songs I listen to (more instrumental type of music) to give you an idea of my music tastes and what I am looking for in equipment to highlight such tastes.
 
The first song I listened to:

 
 
Audio-gd NFB-28 with 1G cable: The opening high notes in this song gave a little hint of distortion/clipping and loss of detail. When the bass drops around 0:31, it is a little loose but not that bad. Soundstage  is very wide and open coupled with my warm-sounding Philips X1.
Geek Pulse Infinity with 2G: Detail throughout. Full stop. I am not sure where this has come from but the 2G cable definitely helps a little bit here when switching between the two. The bass that drops around 0:31 is very tight. Soundstage  is very wide and open coupled with my warm-sounding Philips X1.
 
 
 

 
This next song is faster paced.
 
Audio-gd NFB-28 with 1G cable: While doing a great job on this song, I noticed the small lack of clarity between this DAC and the Geek Pulse. It didn't sound muffled or like it lacked a wide soundstage. It felt like there was some loss of information as if the bit-width shrunk. The next song I chose for it's wide dynamic range (at least to my ears) will hopefully shed more light on this.
Geek Pulse Infinity with 2G: Again, detailed and clear throughout. Sparkly towards the upper end, which is what those chipmunk vocals call for I think.
 

Just because, starting at 3:00 
 
 

 
 
Audio-gd NFB-28 with 1G cable: Hearing Alicia Keys through this DAC made it seem like the music file had undergone file compression. Her voice lost a little clarity and sounded warm in comparison to the Geek Pulse.
Geek Pulse Infinity with 2G: No comment.
 
 
I would go on to play some Norah jones but I think I am seeing a pattern here.
 
 
 
UPDATE (12/19/2015): So I  have decided to keep both. While I find that the Geek Pulse no doubt, offers a very detailed sound in comparison to my audio-gd NDB-28, the audio-gd is very well suited for the type of laid-back, chillwave types of tunes I listen to. The Geek Pulse does very well if I am listening to say Alicia Keys or classical music.

 

[wingsounds13]

Thanks for that. A fully burned in infinity just sounds really good.

That said, I have finally found something that I don't like. My headphone listening has been with a set of ZMF Master model V1 with a ZMF 8 wire balanced cable. Early on, I did check out the different gain levels just to see that they worked. I can get as loud as I like with low gain, so I have been using that all this time. Yesterday, I tried out high gain to see if I could hear any difference. First, I wanted there to be no difference. Second, I wanted any perceived difference to be in the advantage of low gain, where there is less digital attenuation. Dammit!!! I lost on both counts. When I switched to high gain and dropped the digital attenuation another 14dB, I heard an improvement in the depth of the sound stage. It is just more three dimensional in high gain mode. I can't say that it was more solid, stronger, clearer, tighter bass or anything like that, but definitely a deeper image. Low gain just flattens the depth of the soundstage.

This poses an issue that I don't like: I now have to be very careful to turn the level down to about -25dB before plugging the headphones in. Previously, I listened to the headphones at about -11dB, and if I plugged them in with the level set to 0dB for speaker listening the headphones would be playing a bit loud, but not dangerous. 0dB on high gain is REALLY LOUD and probably hazardous to the headphones as well as the ears.

This brings up the thought that Larry implemented the headphone gain control in the amp's negative feedback loop. More negative feedback gives a lower maximum output level, but also messes with the sound. In a well designed amp, it is common for lower negative feedback to sound better, even though the steady state specs are not as good.

Oh Well... I guess that I will have to live with this until I can afford a good headphone amp.

J.P.

 

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

High Gain between -25 and -18 dB depending on music are the settings I like for my HD600. And eagerly waiting for the tube HPA too.

 

[oneguy]

most of my listening is done between -33 and -42dB on my infinty. The HD800 generally require about 5 or 6 dB of less volume compared to the HE1000.

 

[frankrondaniel]

On my Xfi, I find most of my listening, on high-gain, in the 40-45 range with my HD600 and HD800. Anything in the 18-25 range would be much too loud for me.

 

[Shawnb]

Nice just found out I'll likely not make batch 2 so at least another month if not more before my Pulse ships.
What a joke, yet I bet if I bought off Amazon I'd get it sooner

 

[Drsparis]

Nice just found out I'll likely not make batch 2 so at least another month if not more before my Pulse ships.

What a joke, yet I bet if I bought off Amazon I'd get it sooner

How did you find out?  did you purchase before or after December 25Th 

 

[zerograin]

Nice just found out I'll likely not make batch 2 so at least another month if not more before my Pulse ships.

What a joke, yet I bet if I bought off Amazon I'd get it sooner

I bought one off of amazon... While I wait for mine to ship. Let's just say, thank goodness it's on Amazon Prime and their generous holiday return policy.

 

[Shawnb]

  How did you find out?  did you purchase before or after December 25Th 

 
 
Yeah i emailed support. i backed during the Wave campaign so like July 2014 or so.
 
Told me the 2nd batch are to start shipping today and that should complete all 2013 backers, Since i backed in 2014 i'm near the end of the list and might end up in batch 3 and that will be delivered next month

 

[kostaszag]

Today I received my first real headphones, a pair of AKG K340.Oldies but goodies. I plugged them immediately in my Pulse Sfi. I found two things disconcerting. First they only sound loud enough with High Gain mode. I am no bass head, my amp volume knob is almost never beyond 9 o'clock, but only with High Gain at -17.5 was it half way acceptable. The other annoying thing was that when I plug the headphones the speaker output doesn't get silent. Is this normal behavior? It seems hard to believe...

 

[wingsounds13]

The line out on the Pulse does not mute when headphones are connected. This is by design. There are several reasons for this. One is that Larry did not want any relays or switches in the audio path, as this would degrade the sound quality. One substantial reason is that there is no good and reliable way to detect the connection of headphones to the balanced output. While 1/4" phone jacks usually do have a feed through circuit that disconnects when a plug is inserted, this is just another opportunity for signal degradation. Also, it is reasonable that both the balanced XLR and balanced phone jack be treated the same - the device should work the same regardless of which one is used.

If you are getting adequate volume in the headphones on high gain and 17.5dB attenuation, that seems quite reasonable to me. You generally want as little digital attenuation as possible, although circumstances such as mine dictate that I must run my rig around-25dB attenuation with the headphone amp set to high gain. For my setup, that does sound better than low gain and -11dB attenuation.

J.P.

 

[NigelJ]

...I found two things disconcerting. First they only sound loud enough with High Gain mode. I am no bass head, my amp volume knob is almost never beyond 9 o'clock, but only with High Gain at -17.5 was it half way acceptable.

As JP commented that should Allow sufficient volume control headroom. Having quickly checked the web I found that a Headfonia review of the AKG K340 BASS HEAVY VERSION stated:

'The headphone is highly innefficient, requiring only the most powerful kind of desktop headphone amplifiers, and definitely more suitable driven by a speaker amplifier.'

so the high power demand is not surprising.

Edit: The high demands that they place on amplifiers is also covered in the reviews, on this site, that are linked from the following page: AKG K340 Electrostatic-Dynamic Headphones Reviews.

 

[Jupiterknight]

Thanks for that. A fully burned in infinity just sounds really good.

That said, I have finally found something that I don't like. My headphone listening has been with a set of ZMF Master model V1 with a ZMF 8 wire balanced cable. Early on, I did check out the different gain levels just to see that they worked. I can get as loud as I like with low gain, so I have been using that all this time. Yesterday, I tried out high gain to see if I could hear any difference. First, I wanted there to be no difference. Second, I wanted any perceived difference to be in the advantage of low gain, where there is less digital attenuation. Dammit!!! I lost on both counts. When I switched to high gain and dropped the digital attenuation another 14dB, I heard an improvement in the depth of the sound stage. It is just more three dimensional in high gain mode. I can't say that it was more solid, stronger, clearer, tighter bass or anything like that, but definitely a deeper image. Low gain just flattens the depth of the soundstage.

This poses an issue that I don't like: I now have to be very careful to turn the level down to about -25dB before plugging the headphones in. Previously, I listened to the headphones at about -11dB, and if I plugged them in with the level set to 0dB for speaker listening the headphones would be playing a bit loud, but not dangerous. 0dB on high gain is REALLY LOUD and probably hazardous to the headphones as well as the ears.

This brings up the thought that Larry implemented the headphone gain control in the amp's negative feedback loop. More negative feedback gives a lower maximum output level, but also messes with the sound. In a well designed amp, it is common for lower negative feedback to sound better, even though the steady state specs are not as good.

Oh Well... I guess that I will have to live with this until I can afford a good headphone amp.

J.P.

 
Check out the Lycan/Burson headphone amp. Reasonable priced and "relativity" easily enhanced my Geek Pulse HO sonic presentation with (HD600 etc) + I can use the variable output of the Geek Pulse to adjust to the much high powered Lycan which at the same time gives me the headroom that I prefer instead of pushing any given amplifier to a four o' clock setting..

 

[Audio Addict]

Check out the Lycan/Burson headphone amp. Reasonable priced and "relativity" easily enhanced my Geek Pulse HO sonic presentation with (HD600 etc) + I can use the variable output of the Geek Pulse to adjust to the much high powered Lycan which at the same time gives me the headroom that I prefer instead of pushing any given amplifier to a four o' clock setting..

+1 especially with the their new V5 discrete opamp.

 

[kostaszag]

 

...I found two things disconcerting. First they only sound loud enough with High Gain mode. I am no bass head, my amp volume knob is almost never beyond 9 o'clock, but only with High Gain at -17.5 was it half way acceptable.

As JP commented that should Allow sufficient volume control headroom. Having quickly checked the web I found that a Headfonia review of the AKG K340 BASS HEAVY VERSION stated:

'The headphone is highly innefficient, requiring only the most powerful kind of desktop headphone amplifiers, and definitely more suitable driven by a speaker amplifier.'

so the high power demand is not surprising.

Edit: The high demands that they place on amplifiers is also covered in the reviews, on this site, that are linked from the following page: AKG K340 Electrostatic-Dynamic Headphones Reviews.

 

The line out on the Pulse does not mute when headphones are connected. This is by design. There are several reasons for this. One is that Larry did not want any relays or switches in the audio path, as this would degrade the sound quality. One substantial reason is that there is no good and reliable way to detect the connection of headphones to the balanced output. While 1/4" phone jacks usually do have a feed through circuit that disconnects when a plug is inserted, this is just another opportunity for signal degradation. Also, it is reasonable that both the balanced XLR and balanced phone jack be treated the same - the device should work the same regardless of which one is used.

If you are getting adequate volume in the headphones on high gain and 17.5dB attenuation, that seems quite reasonable to me. You generally want as little digital attenuation as possible, although circumstances such as mine dictate that I must run my rig around-25dB attenuation with the headphone amp set to high gain. For my setup, that does sound better than low gain and -11dB attenuation.

J.P.

Thanks to both of you. Does anyone know the power outuput of a Pulse Sfi from a Headphones out at 600ohms? I can't find it on the Lhlabs page (not surprised).