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Light Harmonic Geek Wave - Page 25

post #361 of 3773
Quote:
Originally Posted by germay0653 View Post
 


Actually, the gain switch is only for the XD128 but the IEM package is for all models and specifically designed for low impedance, high sensitivity IEM.  Somewhere on the form they had a list of example IEMs.

 

Free Upgrades for Geek Wave XD 128
For those of you that have purchased the Geek Wave XD128 and have chosen to add the IEM package, we've decided to add a Gain Switch at no extra charge. Switching between pristine IEM output or powerful big-can output allows you to pair your Geek Wave with every set of headphones in your collection.

 

Very true but I see this as the extra mile upgrade, to get the very best possible performance.  If the stock Wave 32 doesn't play nice with my iems, I'll have to declare it a severely compromised portable music player.  Seriously.

 

LH lists the 160mW as max output at 16 ohms.  I used to own the Resonessence Labs Herus, which is rated 126mW into 32 ohms.  I found an online converter and it tells me this equates to 252mW at 16 ohms.  If I'm using this converter correctly (someone please correct this if not true), then the stock Wave 32 and 64 will play nicer with iems than the Herus.  The Herus was very good with most iems- I had the best synergy with the FitEar F111 but it did pick up hiss/noise when no music was playing.  However I had no noise/hiss with the JH13 at the time.  So if these max numbers are correct, I shouldn't need to spend another $128 for perfectly acceptable iem performance; however it would certainly be nice to know this for sure. (I did get the dual dac perk, so it will have a 3db lower signal to noise ratio with, further improving it's performance against the Herus).

post #362 of 3773

The way I see the IEM package is this:

  • The stock Wave uses the TPA6120A2 to act as a current buffer and partly for voltage gain (probably). Despite its issues with output impedance, I still like the TPA6120 as a headamp IC, because it's not only high performance, but for a modern solid-state sound, it produces great sound. Besides, Larry seems to have circumvented the OI problem; how, I don't know (but it's been done before in various ways). The big issue is input bias current on the TPA6120 is said to be pretty high, and apparently that has consequences on output DC offset. I don't know how relevant these issues are, but apparently it was enough for AMB Labs to be concerned.
  • Larry's goal with the IEM package was to lower DC offset and lower overall power. This necessitates changing out the TPA6120 for something else (which is what is stated in the description for the IEM package), such as a pure buffer e.g. LME49600 or BUF634, or some nifty ADI part that I don't know about. A dedicated buffer is likely to provide better current delivery to current-hungry IEMs.
  • The TPA6120 works fine with IEMs, but I always get the feeling that it's happier paired with bigger cans.
  • I get the feeling that Larry will end up using something like the LME49600, in some kind of special modified "diamond buffer" circuit. Then again, I'm no electronic engineer, just one in an armchair.
post #363 of 3773
Quote:
Originally Posted by shotgunshane View Post
 

 

Very true but I see this as the extra mile upgrade, to get the very best possible performance.  If the stock Wave 32 doesn't play nice with my iems, I'll have to declare it a severely compromised portable music player.  Seriously.

 

LH lists the 160mW as max output at 16 ohms.  I used to own the Resonessence Labs Herus, which is rated 126mW into 32 ohms.  I found an online converter and it tells me this equates to 252mW at 16 ohms.  If I'm using this converter correctly (someone please correct this if not true), then the stock Wave 32 and 64 will play nicer with iems than the Herus.  The Herus was very good with most iems- I had the best synergy with the FitEar F111 but it did pick up hiss/noise when no music was playing.  However I had no noise/hiss with the JH13 at the time.  So if these max numbers are correct, I shouldn't need to spend another $128 for perfectly acceptable iem performance; however it would certainly be nice to know this for sure. (I did get the dual dac perk, so it will have a 3db lower signal to noise ratio with, further improving it's performance against the Herus).

It's correct value at volume being at 2V for both loads.  The thing to be aware of is DAPs have current limit, and it will apply to low impedance phone as current is high at low impedances.  Specs will tell you max current.  So you cannot assume based on how much it outputs at 32ohms that it will output double, but that value @32 could be the current limited value or max current.

 

I believe HiFiMan does something similar by offering the slot to the 901 and selling iem cards so that the gain is reduced.  I personally thing HiFiMan 901 is not technically advanced as other player in this regard.

 

Same for the Wave, if the cheapest option is only less sensitive over ear cans, it doesn't seem all that advanced.  Right now we have the DX90 and the X5 that the gain can be switched via software and outputs pretty high power, and plays nice with iems.  

 

Given all these factors and the packages offered, it certainly gives impressions of milking and price gouging.  To me this pledge has too many warning signs for me to stay away.  I won't go into many other factors that to me seems obvious for me to stay away.

 

The only part that stands out is the balanced path.  Mobile 9018 has been done.  

 

The only benefits to the options are for testing out how the sound output changes with differing circuit topologies.  Does fully balanced path make a difference, etc...


Edited by SilverEars - 6/28/14 at 12:53pm
post #364 of 3773
Quote:
Originally Posted by tomscy2000 View Post

The way I see the IEM package is this:
  • The stock Wave uses the TPA6120A2 to act as a current buffer and partly for voltage gain (probably). Despite its issues with output impedance, I still like the TPA6120 as a headamp IC, because it's not only high performance, but for a modern solid-state sound, it produces great sound. Besides, Larry seems to have circumvented the OI problem; how, I don't know (but it's been done before in various ways). The big issue is input bias current on the TPA6120 is said to be pretty high, and apparently that has consequences on output DC offset. I don't know how relevant these issues are, but apparently it was enough for AMB Labs to be concerned.
  • Larry's goal with the IEM package was to lower DC offset and lower overall power. This necessitates changing out the TPA6120 for something else (which is what is stated in the description for the IEM package), such as a pure buffer e.g. LME49600 or BUF634, or some nifty ADI part that I don't know about. A dedicated buffer is likely to provide better current delivery to current-hungry IEMs.
  • The TPA6120 works fine with IEMs, but I always get the feeling that it's happier paired with bigger cans.
  • I get the feeling that Larry will end up using something like the LME49600, in some kind of special modified "diamond buffer" circuit. Then again, I'm no electronic engineer, just one in an armchair.

Has AMB posted their concerns online? I'd like to read up on that.
post #365 of 3773
Quote:
Originally Posted by shotgunshane View Post  Has AMB posted their concerns online? I'd like to read up on that.

 

FYI, they're not specifically concerns about the Wave, and it concerns variable DC offset and output impedance that varies with analog volume control, so I don't know how directly relevant it is. Apparently, volume control within a feedback loop causes issues, even with but that's not an issue for the Wave because of its digital volume control. Here are some quotes, but there are other ones scattered about the internet:

 

Quote:
Originally Posted by peranders View Post  With gain of -1 and 1k as feedback I got 2 and 10 mV offset. The TPA6120 is rather unsuitable to connect to a ordinary but unknown signal source. Why? The amp has rather large input bias currents, 12 uA and this is causing trouble unless you have a buffer.
Quote:
Originally Posted by amb View Post
Quote:
Originally Posted by Garbz
How do input bias currents affect the signal?
High input bias current means that the source impedance changes could cause large variations in output DC offset, unless you use an input coupling capacitor. If you have a volume control pot at the input, then that would consistute a large source impedance change as you rotate the pot. Also, hooking the amp up to different source devices would also cause such change.
Quote:
Originally Posted by amb View Post  Yes, you can use an input coupling cap to eliminate the effect of source impedance variations on DC output offset. Be sure to have a resistor after the coupling cap to ground, to provide a path for the input bias current. This needs to be sufficiently high in resistance not to load down the source output and change the taper curve of the volume pot. In this case I suggest using a 10K ohm volume pot, and use at least a 47K ohm resistor for the input bias resistor.

Note that even with the input coupling cap it might not be enough to make the output offset low enough. To minimize the offset you need to select the two negative feedback resistor values such that their paralleled value is close to the input bias resistor, but with a 47K resistor at the input, you'd have to use fairly high value feedback resistors, which is not good for noise performance. It's an unfortunate tradeoff with using devices with high input bias current. The only recourse is to either add a large capacitor on the leg of the negative feedback resistor that goes to ground (so that the DC voltage gain of the amp is reduced to 1), or add an output coupling cap, or both. Evil stuff.
post #366 of 3773
Just so you guys know in case you don't get the e-mails, LH is launching their Geek Source music server device in 20 minutes on the Geek Wave campaign.
https://www.indiegogo.com/projects/geek-wave-it-s-not-a-next-gen-ipod-it-s-a-no-compromise-portable-music-player
Quote:
Geek_Source_SM.jpg

We've developed a bit of a notoriety (or maybe we're just notorious) in the industry for pushing the envelope on product design and product features. Well, we're at it again.

We'd like you to meet Geek Source, the "soul mate" your Geek Wave & Geek Pulse are destined to be paired with.

As its name suggests, Geek Source is THE BEST music source in your home stereo. Geek Source is the most powerful and high-end music server available for under $1000. Not only does it pair perfectly with Geek Wave, but it was also specifically designed with Geek Pulse in mind. Talk about a two-fer!

We've utilized technology from Light Harmonic's Da Vinci Source, a project that we began working on in 2012 and unveiled at the 2013 Consumer Electronics Show, pairing it with our world-renowned Da Vinci DAC. The results were stellar.

Just like Geek Pulse's relationship with Da Vinci DAC, Geek Source's core design is directly derived from our soon to be released ultra high end music server: Da Vinci Source (MSRP $12,999). Same concept, same core technology, same development team, dramatically different price.

After wrapping up the Geek Pulse campaign, we realized the vast majority of audio enthusiasts were looking for a replacement for their computer-based music servers, usually a multi-media PC or Mac Mini. From this often overlooked necessity, Geek Source has been intelligently designed to be the last music server you'll ever need.

Geek Source Is A Feature Freak
  • Geek Source features a whopping 2TB (4TB optional) of internal hard drive storage space. That's enough space to store 5000+ Hi-Rez tracks or 50,000+ CD quality tracks!
  • Built in Double Phase Re-Clock Jitter Elimination circuit for all output digital circuits. Every digital output is precisely timed making it the perfect fit for any system that has a dedicated DAC.
  • Many of us have trouble playing FLAC or DSD files with iTunes. Fret no more. Geek Source is a high resolution music playing specialist. Looking to play FLAC, DSD, DSD2, DXD and 384K? Geek Source handles it all.
  • Dedicated USB audio class 2.0 output with a noise free power supply. This isn't your Grandpa's PC or MAC music server. Geek Source is a super high speed playback machine.
  • Less noise, more music. Geek Source has an external power supply, keeping the bad noise at bay while letting the good noise (your tasty tunes) in.

How Geek Source Works With Geek Pulse
Connect the USB cable from Geek Source to Geek Pulse and you're ready to rock. Best sounding combination under $3,000, no question about it.

How Geek Source Works With Geek Wave
Geek Source syncs with Geek Wave as a music storage source, backing up your music files onto Geek Source's hard drive. This is where it gets interesting, Geek Source features the ability to have analog playback while Geek Wave is synced to it, through your home stereo. Mind. Blown.



post #367 of 3773

Geek Source is up for perk on geek geek wave site.  FYI first 100 $699, half are gone already.


Edited by thirdman - 6/28/14 at 9:41pm
post #368 of 3773
Quote:
Originally Posted by thirdman View Post

Geek Source is up for perk on geek geek wave site. FYI first 100 $699, half are gone already.

I personally don't have a use for the Geek Source though. I don't even have something like a Mac Mini server since I don't have enough music. XD
Edited by miceblue - 6/28/14 at 9:47pm
post #369 of 3773

thanks.  Yeah, the specs look good. But I don't have a need for one right now either.


Edited by thirdman - 6/28/14 at 9:47pm
post #370 of 3773

Yep, no need for one right now either... If I need one later on, well I don't think I'll be too annoyed about the $100.

post #371 of 3773

All EB Geek Source are GONE! Well, that could be considered quick...  Almost $70k in under two hours, not a bad bit of funding.


Like their nifty bit of cross advertising - pulling Pulse backers in to look at the Source and then have some purchase Wave too!
Nicely done LH, nicely done.

post #372 of 3773

i can't get this question answered by anyone from light harmonic, so i was wondering if i committed to the geek wave 32 but after the campaign ended (before manufacturing deadlines) wanted to do the upgrade to the xd 128 or something would that be something light harmonic allow or would i be locked in?

post #373 of 3773
Quote:
Originally Posted by raisedbywolves View Post
 

i can't get this question answered by anyone from light harmonic, so i was wondering if i committed to the geek wave 32 but after the campaign ended (before manufacturing deadlines) wanted to do the upgrade to the xd 128 or something would that be something light harmonic allow or would i be locked in?

 

They've been allowing upgrades for the other campaigns after they've ended. It seems most times you'll pay a bit more, but the options are available. I can't promise they'll do the same with the Wave but the pattern is there.

post #374 of 3773
Quote:
Originally Posted by AxelCloris View Post
 

 

They've been allowing upgrades for the other campaigns after they've ended. It seems most times you'll pay a bit more, but the options are available. I can't promise they'll do the same with the Wave but the pattern is there.


what was the markup generally? it's just that i can see the landscape changing a lot in the dap world by the time the geek wave is ready to be release. and given how badly they've overshot estimates for their previous projects, i can't see march 2015 being a for sure thing, so i'd rather invest in the lowest option available and then if it turns out there's good feedback on early pre-production geek waves then i can upgrade. if not or other daps come out on the market that are more appealing to me then at worst i can just sell the geek wave 32 and recoup the loss.

post #375 of 3773
Quote:
Originally Posted by raisedbywolves View Post
 


what was the markup generally? it's just that i can see the landscape changing a lot in the dap world by the time the geek wave is ready to be release. and given how badly they've overshot estimates for their previous projects, i can't see march 2015 being a for sure thing, so i'd rather invest in the lowest option available and then if it turns out there's good feedback on early pre-production geek waves then i can upgrade. if not or other daps come out on the market that are more appealing to me then at worst i can just sell the geek wave 32 and recoup the loss.

 

It varies. The Pulse X upgrade remained the same throughout both campaigns and the Pulse backer survey. But the internals upgrade was $88 at first and then $99 later. Backers in the Pulse campaign could get a GO for $99, and they can get one now for $149. It's whatever pricing scheme they choose to use.

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