Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › VentureCraft Go-Dap GD-04 for iPhone 4
New Posts  All Forums:Forum Nav:

VentureCraft Go-Dap GD-04 for iPhone 4 - Page 9

post #121 of 161

No it doesn't. Nor would remotes work with Fostex HP-P1, or CLAS+Amp combo's too.

post #122 of 161
Quote:
Originally Posted by AnakChan View Post

My personal preference of the OpAmp is the AD8397 but I don't know if VentureCraft has anymore of those. There other popular one is the OPA1612, and more recently VentureCraft has added AD8066 to their OpAmp option suite (but I've not listened to them yet).

 

FYI, I contacted Venturecraft about getting a custom Go-DAP, and the OPA1612 and AD8397 are no longer available.

post #123 of 161
Quote:
Originally Posted by AnakChan View Post

No it doesn't. Nor would remotes work with Fostex HP-P1, or CLAS+Amp combo's too.

 

Thanks for the clarification.

post #124 of 161
Quote:
Originally Posted by brumma View Post

Quote: Originally Posted by AnakChan My personal preference of the OpAmp is the AD8397 but I don't know if VentureCraft has anymore of those. There other popular one is the OPA1612, and more recently VentureCraft has added AD8066 to their OpAmp option suite (but I've not listened to them yet). FYI, I contacted Venturecraft about getting a custom Go-DAP, and the OPA1612 and AD8397 are no longer available.
Yeah, it seems when VentureCraft comes up with some OpAmp versions, they order and make only a limited number. AD8397 is also unavailable now (& I don't think they have plans to bring in anymore).

The OPA1612 maybe unavailable now but I wonder what will happen when V-Moda wants more VAmps (which are OPA1612 based). I'm sure VentureCraft can't just simply switch on them so quickly the way they do with the Go-DAPs.

Mind you, I'm literally, right now, reviewing the AD8066 VentureCraft has loaned me (they want me to write a mini-impression), and for the 1st hr, I wasn't impressed with them vs. the OPA1612. But after the quick 1 hr burn-in, the tables have turned!! The AD8066 is sounding more 3 dimensional than the OPA1612!! I'm gonna burn them in longer to compare against my personal fav AD8397.

If the AD8066 continues to sweeten over a longer burn-in, I think V-Moda may have jumped the gun with the OPA1612 for the VAmp.

Edit: the differences aren't night 'n day but more apparent on some tracks than others.
post #125 of 161
Quote:
Originally Posted by AnakChan View Post


Yeah, it seems when VentureCraft comes up with some OpAmp versions, they order and make only a limited number. AD8397 is also unavailable now (& I don't think they have plans to bring in anymore).
The OPA1612 maybe unavailable now but I wonder what will happen when V-Moda wants more VAmps (which are OPA1612 based). I'm sure VentureCraft can't just simply switch on them so quickly the way they do with the Go-DAPs.
Mind you, I'm literally, right now, reviewing the AD8066 VentureCraft has loaned me (they want me to write a mini-impression), and for the 1st hr, I wasn't impressed with them vs. the OPA1612. But after the quick 1 hr burn-in, the tables have turned!! The AD8066 is sounding more 3 dimensional than the OPA1612!! I'm gonna burn them in longer to compare against my personal fav AD8397.
If the AD8066 continues to sweeten over a longer burn-in, I think V-Moda may have jumped the gun with the OPA1612 for the VAmp.
Edit: the differences aren't night 'n day but more apparent on some tracks than others.

 

So the OPA1612 and AD8066 have similar sound coloring?  How does the AD8066 compare to your favorite AD8397?  I read one criticism of the AD8066 that said it had a "boring mid-range."  Any thoughts on why they may have said that, sincet seems as though you are enjoying your sample?  Getting ready to pull the trigger myself.  Almost there...

post #126 of 161
I won't use the word coloring but I'd say similar signatures instead. Do bear in mind though with all the OpAmps I've tried with the GoDAP, the amps aren't vastly different (except for the Muses 8820E, OPA2134' & OP-275 maybe; but the OPA1612 & AD8066 are very similar with subtle differences, I'd personally put the AD8397 in its own category to what I'm listening -right now-).

So to answer your question about the AD8066 & AD8397, I'm not gonna mince my words today & say that the AD8397 still smacks the AD8066 in the face. The detail, depth and 3D-ness of the AD8397 still reigns. At some point though (depending on headphone synergy) the AD8397 could sound a little sibilant but that depends on the headphones & only some tracks.

I'm going to listen across more genre to give a more in-depth impression but for now I'd still prefer the AD8397, then a couple of steps away the AD8066 with the OPA1612 one step behind the AD8066.

Edit: Throwing in pix of my test today (AD8066, AD8397, iPhone4 S, new iPad, some el-cheapo iPod cable extender, UM Merlins)

263
post #127 of 161

So almost a month later I'm in a position to provide a more thorough review of the Go-DAP 4.0 with the AD8066 OpAmp. This has been a somewhat difficult listening experience because I've gone back and forth between the AD8066 & the OPA1612 on numerous occasions - each time burning in the AD8066 more (whilst the OPA1612 has had hundreds of hours of burn-in).

 

 

What's the verdict? Believe it or not, I have found that the AD8066 and the OPA1612 so close to each other that they're almost indistinguishable from each other. In fact this is the reason why I had to go back and forth so many times 'cos each time I focused on each one, I found them so close that I didn't believe it myself and had to find difference between the two. And that's where it gets dangerous 'cos placebo starts to manifest (as such my June 12th comments to Brumma). So the final bottom line after many many hours of burn in of the AD8066, and many many hours of listening between the two (even giving myself a week's break in-between hrs of listening), my personal conclusion is that they are too similar to try to nitpick.

 

But did I hear a difference between the two? I'd rather err on the side of caution to say that I'd like to think I did for certain tracks only. I even whipped out my favourite AD8397 to confirm that my ears were tired from A/B-ing too long. As such the following are the rough notes I made during the comparison between the AD8066 and OPA1612, and later with the AD8397.

 

According to Go-DAP 4.0 manufacturer, the AD8066's main feature is that it's a "FastFET" with a 145MHz which is supposedly suitable for "fast" music. As opposed to the other OpAmps VentureCraft has put into the Go-DAP, the OPA1612 is a "WideBandwidth" 40MHz, and the AD8397 being a 69MHz. For reference, the Muses 8820E is an 11MHz whilst the OPA2134 is 8MHz.

 

I have to admit that OpAmp frequencies in this respect is beyond my knowledge. Although I understand these frequencies in computing terms but what it means to music (or as the manufacturer is alluding to, genre of music) I'm not certain. According to the makers, the reason why I may not hear a difference between the OPA1612 and AD8066 is that the music I listen to are may not see the benefit of the speed of the AD8066 - a reasoning I'm willing to accept.

 

 

Reboot: Back to Scratch Review

 

As such, back to the roots of merely comparing the Go-DAP 4.0 with AD8066 against a barebones iPhone 4(S). What does an iPhone 4(S) user gain by using the VentureCraft Go-DAP 4.0 with an AD8066?

 

The Go-DAP provides an integrated iPhone 4(S) jacket that's free of any external LOD cables and presents a multi-purpose/multi-component into a single integrated device.

 

DSC_1475.jpgDSC_1478.jpg

 

Size comparison to another popular multi-component setup with external LODs ands interconnects :-

 

DSC_1480.jpgDSC_1481.jpg

 

However, this doesn't mean that the VentureCraft Go-DAP 4.0 becomes obsolete with the iPhone 4(S). It basically works with any current iOS device with an iPod extended cable (NB: iPhone, iPod Touch, Nano, iPad. However it is not compatible to the iPod Classic). So in "worst case" scenario, it can operate in multi-component mode, like it's competitors.

 

DSC_1484.jpg

 

Features

 

  • AKM AK4353 DAC
  • Analog Devices AD8066 OpAmp (Base OpAmps start from Muses 8820E or Burr Brown OPA2134)
  • 1580mAh battery that can be used entirely for the Go-DAP DAC/Amp, and/or charging your iPhone
  • Low/High Gain Switch
  • Acoustic Sound Retriever (ASR) to recover details lost in lossy compression
  • Transport functionality by having 3.5mm Optical Out to an external DAC
  • Manufacturer-upgradeable battery to 2200mAh
  • Manufacturer-upgradeable OpAmp of customer's preference (menu-style offering from manufacturer)

 

Practical Operation

 

 

The Go-DAP takes approx 4-5 hrs to charge the 1580mAh battery and when used completely in DAC/Amp (marked as "Amp" on the toggle switch) lasts approximately 7 hours of continuous use. When the battery is used to charge the iPhone instead (marked as "Amp-i" on the toggle switch), it lasts for approximately 1 hr and the iPhone is charged up to 48% (from a completely depleted absolute 0% battery charge). I usually use it in "Amp" mode unless I'm really running low on juice on my iPhone.

 

The Go-DAP must be charged separately from use - i.e. you cannot simultaneously charge whilst actually using it. It charges via mini-USB at the base and has to be switched into Amp or Amp-i mode to charge. When the mini-USB is plugged in, and it's in either of those modes, it'll prioritise to charging instead of audio/listening mode.

 

However if the mini-USB is plugged whilst the toggle switch is in "Sync/Off" mode, the Go-DAP is switched off and the mni-USB changes to pass-through mode and your iPhone will sync with iTunes. Naturally if there's no iPhone there, it doesn't do anything (including NOT charging the Go-DAP!).

 

Confused? Here's a table :-

 

Go-DAP 4.0 Operational Chart
  Sync/Off Amp-i Amp
Mini-USB In iPhone/iTunes Sync Go-DAP Charging Only Go-DAP Charging Only
Mini-USB Out Go-DAP 4.0 OFF Mode iPhone Charging/Music Mode Music Mode

 

Meanwhile, the optical out is always on. It's the same jack port as the for the Single Ended 3.5mm headphone out.

 

The 70mW+70mW (32 ohm) output drives most earphones and headphones well. Of course though if you have the "hard-to-drive" headphones like HD800s, Hifiman series, or LCD-2/3s then it would be somewhat of a struggle for the Go-DAP. V-Moda VAmp followers may note though that the VAmp version of the Go-DAP outputs 150mW+150mW. This feature, the ASR replaced with VQ, and the OPA1612 OpAmp are customisations specifically designed by the VentureCraft fo V-Moda.

 

Sound Quality

 

The VentureCraft Go-DAP 4.0 in this AD8066 OpAmp iteration provides transparent and detail presentation over the straight headphone out of the iPhone 4S. Pretty much across all genre of music I've listened to - Classical, old 50s/60s West Coast Jazz, BossaNova, Vocal Jazz, 80s, 90's pop, and instrumental movie soundtracks some modern Hip-Hop - the tracks are presented in a more transparent way like a veil was lifted. There's more clarity across the frequency (although more prevalent in the mids and highs in most tracks, and some kinds of music, in the basses too). Basses in most songs are decently extended yet tightly controlled (e.g. picking Black Eyed Peas, Boom Boom Pow as an example). Bear in mind though the IEMs (Unique Melody Merlins, FitEar TO GO! 334) and headphones (Fostex TH900) I use with the Go-DAP are decent themselves.

 

Vocals are also smoothly with clarity and precisely as opposed straight out of the iPhone, can sound somewhat muddy. The presentation of the mids also sound somewhat more 3 dimensional with a little more depth to the stage, whilst the overall soundstage is decently extended.

 

Treble is also nicely extended. And although initially may sound a little harsh and sibilant, after a about a decent 1 week (off/on) burn in, the trebles are much smoother and controlled. The soundstage width and depth also extended nicely.

 

In my honest opinion, although VentureCraft provides a suite of OpAmp options to the customer, the AKM AK4353 DAC plays a major part in it's ability to retrive sound quality and the OpAmp of choice further enhances what comes out of that DAC.

 

Summary

 

Although I personally own a suite of other DAPs and DAC/Amp combinations and some can be challenging to the Go-DAP SQ-wise, none have so far been able to beat the integration of the Go-DAP into a neat little package with top quality sound. To strive for greater detail or greater amp power, a listener would have to sacrifice something else - primarily integration but to a lesser extent on-the-move portability. Of course one could carry a dedicated DAP but then would have to manage 2 devices - DAP and phone. For those who are happy to have their music on their iPhone and strive for improved sound quality without sacrificing integration, the Go-DAP is a neat package.

post #128 of 161

My impression of using Go-DAP 4.0:

 

I receive this about a month ago. 

 

Packaging:

I am very impressed with the packaging of Venturecraft Go-DAP 4.0. The unit when you receive is shrinkwrapped and 'floating' inside the box. You can bounce the box, drop it from 4-5 meters and the product would be safe. 

The manual is also nicely done. It communicates confidence and thoughtfulness from the company. 

(I am a distributor for high end recording equipment, and you'd be surprised units 10x the price of Go-DAP doesn't have a manual or as well written as this)

 

The build quality is excellent too! Love the fact that it is Made in Japan, at a very modest price of $425. 

 

Let's go straight to the sound:

 

I use my Unique Melody Mage and my Mrspeakers Mad Dog to evaluate the Go-DAP. I didn't have any other portable dac/headphone amp to compare it with.

 

UM Mage has a very balanced bass to mids frequency response. It sometimes lack high frequency extension. The reverb decay and details are often missing when listening straight from the iphone4s. 

With Go-DAP, the difference are not subtle. It opens up the high frequency, and also added a bit of punch to the snare and guitar strumming. Vocal remains solid and the center of attention. Low end is tighter/cleaner as well. 

Mrspeakers Mad Dog is a bit hard to drive. With my iphone4s volume all the way up, I still don't feel that it's giving enough volume. I had a different experience listening to the Mad Dog from a Dangerous Monitor ST headphone out. 

With Go-DAP, the difference between iphone4S, it has cleaner bottom, tighter image and more extended high frequency. After listening to different reference songs, songs that I work on, I find that I am now confident to share the tone characteristics of Go-DAP.

 

Go-DAP 

Bass: It's got a clean, tight bass sound. Don't expect the unit to add more bass, but expect a cleaner bass.

Mids: Somehow I felt that mids are tighter with Go-DAP than with the iphone4S. 

Treble: It has a sparkly high frequency extension that is going to sound great with music that are sparse and 'reverby'. 

Imaging: Imaging is tight. I can definitely tell clearly where the instruments and vocal sit with Go-DAP than without. Stereo field of instruments, types of delay/reverb chosen, processing on vocals are easily guessed. 

Depth: Enough depth information and positioning of front to back of music/vocals. 

 

With my UM Mage, I feel that Go-DAP has given an added value to the IEM. 

With Mrspeakers Mad Dog however, I feel that Go-DAP is not really suitable for headphones that are hard to drive. Even at a higher gain, I still have to crank the gain till it's maxed out and still it couldn't drive the headphone easily. 

 

As for things that can be improved:

 

1. I wish I can still use the unit when the unit is still being charged.

2. A switch for an inefficient headphone would be great

3. A stronger battery  (have to switch back to my iphone4s)

4. When the signal of phone was bad, even in the US, I experienced a dropout of sound and also signal interference. 

post #129 of 161

I picked up a used Go-DAPs for a good price and wanted to potentially mod it.  If I'm not worried about warranty can I go in an change the Op Amp?  OPA2134 is not wowing me, especially at the low end.  From what I am reading it sounds like everybody is ordering them custom from the factory but it appears I can get in the case with a hex wrench.  And the battery has ~500 charge/discharge lifetime which is longer than most would probably keep it anyway.  However, wouldn't hurt to pick up an extra battery for the future.  The previous owner probably did not put in many hours on it so I'm going to run it before I decide whether or not to keep it.    

post #130 of 161
Not that I'd advocate modding the Go-DAP but if you're comfortable soldering SMD's, why not? Check out compatible pinout OpAmps though.

Outta curiosity where did the 500 charge limit come from?
post #131 of 161

Instruction manual that came with the Go-Dap indicates 500 cycles.  

 

Quote:
Originally Posted by AnakChan View Post

Not that I'd advocate modding the Go-DAP but if you're comfortable soldering SMD's, why not? Check out compatible pinout OpAmps though.
Outta curiosity where did the 500 charge limit come from?
post #132 of 161

I just upgraded my iPhone 4 to iOS6 and it is causing major issues with the Go-Dap. It will still charge the iPhone even if it is in amp only mode. Is anyone facing similar issues?

post #133 of 161
Quote:
Originally Posted by StereoHeadphone View Post

I just upgraded my iPhone 4 to iOS6 and it is causing major issues with the Go-Dap. It will still charge the iPhone even if it is in amp only mode. Is anyone facing similar issues?


  I suggest you to contact the manufacturer to see if there is a remedy to solve  your GODAP 4 issue. 

post #134 of 161
I've just informed VentureCraft of your issue.
post #135 of 161

So VentureCraft just tweeted that they're checking the iOS6 & Go-DAP 4.0 always charging regardless of Amp or i-Amp mode. They will announce their findings later this week. Presumably this is also applicable to V-Moda VAmp too then.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Portable Headphone Amps
Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › VentureCraft Go-Dap GD-04 for iPhone 4