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Furutech ADL GT40 - Page 2

post #16 of 38

I think that's a good deal but IMO USB cables don't do anything. I have a Belkin USB cable and it's as good as $1,000 ones. It's just a digital signal. 

 

Sorry for slight derail....

post #17 of 38
Actually I found a uk retailer selling this for £400. Still far off $300!

So with that short comparison with the nuforce it looks like this thing may loose out slightly. More bright than the hdp- maybe only suited for dark cans then.

One slight thing of concern that i haven't been able to deduce from online reviews is whether or not the headphone jack would be noisy if used with iem's/customs. Could someone with them test this if possible.
post #18 of 38

I had mine for a little while now & I love it - or should I say loved it.. because my GT40 started to demonstrate (with) a lot of static build-up, jitter & other beeps & cold war noises, so it's going back tomorrow for a swap.

 

However, before it's breakdown it did what it was supposed to do very nicely. The 24/96 MM vinyl dubs it produced so far were excellent, & the Amp is pretty solid as well with good tonal balance, clarity, quality & color, but I found it to be a bit too "bass-lite" - which makes it sound a tad bright (for my taste that is) - with my AD2000 & AD900, but my D7000 & T70p love it to bits, + I got a hunch that the Philips Fidelio L1 might just be the perfect match - it having a slightly darker image with low impedance & high efficiency.

 

Anyway, I been having lots of problems with it & hope a new one will resolve because it's a great little performer.

 

This review sums up pretty much what I found: http://www.6moons.com/audioreviews/furutech10/1.html

 

Btw I paid € 469.- including shipping (NL).

post #19 of 38
cold war noises, lol.

so these noises were present when using it as a dac/amp, or just from the analogue to digital conversion operation?
post #20 of 38

 


 

Quote:
Originally Posted by CantScareMe View Post

Actually I found a uk retailer selling this for £400. Still far off $300!
So with that short comparison with the nuforce it looks like this thing may loose out slightly. More bright than the hdp- maybe only suited for dark cans then.
One slight thing of concern that i haven't been able to deduce from online reviews is whether or not the headphone jack would be noisy if used with iem's/customs. Could someone with them test this if possible.

 

They say it's darker? Oh yeah.

 

I don't know exactly what dark is like but I find the GT40 bassy. And I'm not alone I have read it in a few reviews. When I use the headphone amp with different DACs I never get as much bass as I get when I use the dedicated internal DAC of the GT40 via USB. Two reviews I have read said the GT40 paired well with the Grados (which is good for me :), and one of these stressed that the GT40 and the Grados had *very good* synergy together.


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http://www.goodsound.com/index.php?option=com_content&view=article&id=239:furutech-alpha-design-labs-gt40-dac-and-headphone-amplifier&catid=56&Itemid=37 (one of the best reviews around, because it tells a lot about every components, only problem is that not enough emphasis is put on the DAC and the Amp portion of the GT40)

 

Even though Head-Fi doesn't talk about it (even though Alpha Design Labs has been added quite recently in the list of the sponsors), this thing has been reviewed many times around the globe: http://www.adl-av.com/products/usbdac/gt40/#reviews (list of all the review)

 

 

It's dead silent (but not at all silent of the music) with any headphones including IEMs :), up until half-way on the volume knob. With IEMs at this point you start hearing a very slight pink noise, but you can't really notice it between songs yet. With other headphones you don't hear anything at that level yet. At 3/4 you hear hiss on both types of headphone and you know its there between songs.

 

1/4 is more than enough volume for casual listening and for longer periods. 2/4 is already very loud and I won't listen to longer than one song on such a level, because it's excessive already. 3/4 will damage your hears in the long run, but it's still listenable. 4/4, maxed out headphone amp, is pain... I've tried it, but you gain nothing from doing that, try it at your own risk and the risk of your headphones.

 

While I don't think the GT40 would blow up a pair of headphones, it still drives my T50RP wonderfully, I think its my hardest to drive headphone. I have read at three places that it could drive the HD800 fairly well, but that it wasn't top notch.

 

There are the first 7% of the volume knob that doesn't produce sound, I am bit annoyed by that I must say.

 

You hear hiss only with the headphone amplifier. The line out is perfectly clean from 0 to 100% volume (yes you can control the line out volume with the front knob) (it controls both volumes at the same time so you have to shut your speakers to listen to the headphone only, or vice-versa if you want to hear only the speakers). The line out doesn't sound as good as the front amplified jack with headphones, but the line out gets the job done as a preamp for powered 2.1 computer speakers.

 

The volume knob is either silent or slightly noisy, when you're leveling during a song.

 

Finally when the GT40 is on standby (LEDs are shut), but still connected to the power outlet, you will want to unplug your headphones because you hear the current flowing through it. It's not loud at all but it uses the diaphragm for nothing, so I do it.

 

These were all my nitpicks.

 

I know the GT40 very well around, and almost all the reviews about it. Don't hesitate to ask me more questions if you have, I can even provide you with a 96/24 vinyl recording by it.

 

 

 

Quote:
Originally Posted by rabor View Post

I had mine for a little while now & I love it - or should I say loved it.. because my GT40 started to demonstrate (with) a lot of static build-up, jitter & other beeps & cold war noises, so it's going back tomorrow for a swap.

 

Rabor, you look to be referring to a part of the issue likw this guy on Amazon had: http://www.amazon.com/Furutech-Gt-40-Phono-headphone-Amp/product-reviews/B005KSKPHK/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

 

I think I know what you guys are talking about, or at least one part of it.

 

Know that the volume knob isn't perfectly insulated. From 1/4 to 3/4 you hear a fair amount of a trembling, oscillating static/machine gun noise (not the same hiss of the amp, but those add up together), but only when you're touching the volume knob! Remove you fingers and you're back at silence. This is only annoying when you're playing to find the perfect low volume of a song when the instruments aren't playing loud, you hear the oscillating sound. Otherwise, when music is playing back normally and you're adjusting the volume, you can't even hear it because it's not loud. I don't put it in my nitpicks for that reason, it's only audible when music isn't playing back or playing back not loud.

 

I think it is only a problem with the headphone amp as you don't hear it when listening to the line out, or in the recordings (those are automatically volume adjusted if I remember correctly).

 

I don't know what jitter you're hearing. I don't know what jitter sounds like. Once a day max the GT40 might skip when your processor is fully loaded, but it's nothing to care about lol.

 

Static build-up again I'm not sure of what that is in the sound being played back. Sometimes when I lift from my chair the sound cuts off, I think it is some kind of protection against static, the GT40 locks up and even Windows Media Player or foobar2000 stop playing back music and put it on pause, and you can't unpause or press play to change that (it seems to be a driver thing). What you do is just push the on/off button in and out and it gets back playing by itself, just like it was doing, in the same moment it had cut. Again that's a once in a week thing, nothing to get alarmed out of.

 

 

I think every device has that kind of nitpicks and I'm sharp and demanding enough to find them all, usually. I haven't played much with the ADC but for playing back music all that I said here you will also have to deal with them (most probably). But believe me, it's just like nothing! Those are the smallest possible issues one can have with that kind of device, and dealing with them is plain easily. Those are either tiny issues, or rare and easily fixable ones.

 

 

*Edit: Oh and if you want to hear how bassy the GT40 can be, just listen to it straight out of its line out. It will give you a more neutral sound and let you appreciate more all the bass that is already present in the amplified headphone jack ;). It's bassy, but not overly so to think you would be listening to the bass boost of a DAP or something. I love that bass for my headphones that needs it. With my most bassy headphones I sometimes listen to the line out, for the reason I just stated. But keep in mind that the amplified jack still sounds better most of the time (with headphones) than the line out.


Edited by devouringone3 - 3/11/12 at 3:15pm
post #21 of 38

Quote:

Originally Posted by CantScareMe View Post

cold war noises, lol.
so these noises were present when using it as a dac/amp, or just from the analogue to digital conversion operation?

 

I would also like to know more about these noises. I have never heard about such "cold war noises".

post #22 of 38
Thanks for the impressions and the links to more reviews guys. Really helpful.

But i have to say that i'm looking for a completely static and white/pink noise free unit when operating in normal situations. I've virtually stopped using the fiio e9 even for a casual rig as i hate the static i hear through my headphones when adjusting volume. This is a permanent issue with this amp, and i don't want to meet another perpetrator!

It must be difficult for the gt40 to avoid things like this as there's so much stuff crammed into one small box. It'll just be amazing if i can find a small book size all in one amp/dac like this that competes really well with the 10kg+ desk sized monster units out there. <£500 would be nice.

Desktop unit thats mains powered, smaller in size than a netbook laptop, transportable < 1 kg....
Tried a few contenders like the nuforce hdp, audinst mx1, audio gd nfb 12. Not that impressed really.
post #23 of 38

It's behavior is erratic to say the least; sometimes there's just a some mild static noise, beeps & clicks but that can be solved quite easily by unplugging it from power & USB (a couple of times), but sometimes there's real hard static noise, like a tube radio not tuned to a station with loud frequency loops & Morse in the background, & then it doesn't matter if you listen to the DAC, Line or Phono, it's everywhere on every volume level & every sound coming through is heavily distorted. I tested on 3 different computers with several USB-cables, so I'm pretty sure it's the GT40, but like now it's as silent as ever before.

post #24 of 38
No reason not to believe you.

looks like i'll pass on this one then- but thanks for the info.
post #25 of 38

Edit: It just died..

 

Only a big loud hum now coming from the headphone amp out - no USB connected. R.I.P.

 

Next..

post #26 of 38

Quote:

Originally Posted by CantScareMe View Post

But i have to say that i'm looking for a completely static and white/pink noise free unit when operating in normal situations. I've virtually stopped using the fiio e9 even for a casual rig as i hate the static i hear through my headphones when adjusting volume. This is a permanent issue with this amp, and i don't want to meet another perpetrator!

Most of the time adjusting the volume knob is absolutely noise free. This was also an important characteristic for me, that I was looking for when I bought the GT40; I had crossed my fingers. It takes IEM or John Grados (32 ohm) to hear the "machine gun sound" (and this sound isn't loud, I will call it "buzzing sound" from now on) it does when touching the knob that isn't perfectly insulated. With Joseph Grado HP2 I'm not hearing it (40 > 32 ohm impedance, I don't know if it has anything to do with it, I don't want to say "sensitivity" just yet).

 

The static noise you get when adjusting the volume is random, most of the time I don't have it. It might depend on how charged I am in electricity or on the atmospheric conditions or both I don't know.

 

It means that from 0 to 50% knob, with HP2, normal-good electricity level and/or atmospheric conditions, I can adjust the volume absolutely noise free, in silence or in music.

 

After 50% you get something that isn't static or "buzzing sound" (just my way of calling it) noise: hiss, which I would describe to be similar to a pink noise, or even a brown one. This you get it, starting at 50% volume (barely noticeable with HP2, but noticeable with IEM albeit being very low; in between tracks you might not notice it) for the headphone amplifier (front headphone jack), no matter what you do, but you don't get it if you connect your headphone to the RCA line out at the back. Which is wasteful to do so if you want a real amplifier, lol. The line out won't play very loud, half volume is good for regular listening and full volume is too loud but still a lot more tolerable. The line out volume is knob controlled also and is absolutely noise free.

 

 

 

Quote:
Originally Posted by rabor View Post

It's behavior is erratic to say the least; sometimes there's just a some mild static noise, beeps & clicks but that can be solved quite easily by unplugging it from power & USB (a couple of times), but sometimes there's real hard static noise, like a tube radio not tuned to a station with loud frequency loops & Morse in the background, & then it doesn't matter if you listen to the DAC, Line or Phono, it's everywhere on every volume level & every sound coming through is heavily distorted. I tested on 3 different computers with several USB-cables, so I'm pretty sure it's the GT40, but like now it's as silent as ever before.

 

Mine certainly isn't like that, lol. Mine functions normally, no matter all the nitpicks I enumerated.

 

 

Quote:
Originally Posted by rabor View Post

Edit: It just died..

 

Only a big loud hum now coming from the headphone amp out - no USB connected. R.I.P.

 

Next..


Wow this sucks to hear :(, even more for me that currently uses one. I would like it to last much longer in my hands, lol :-/.

 

What have you done to it? May I inquire, lol. I hope you didn't tried to listen to your computer via USB with the black toggling switch at the back of the unit moved to MC or MM.

 

And please tell me if your replacement unit is any better!

 

*At max volume there is "always" (even with USB cord disconnected) a loud hum coming from the headphone amp out. That's the pink/brown noise I'm talking about. What volume were you at?


Edited by devouringone3 - 3/11/12 at 4:21pm
post #27 of 38
Quote:
Originally Posted by devouringone3 View Post

Wow this sucks to hear :(, even more for me that currently uses one. I would like it to last much longer in my hands, lol :-/.

 

What have you done to it? May I inquire, lol. I hope you didn't tried to listen to your computer via USB with the black toggling switch at the back of the unit moved to MC or MM.

 

And please tell me if your replacement unit is any better!

 

*At max volume there is "always" (even with USB cord disconnected) a loud hum coming from the headphone amp out. That's the pink/brown noise I'm talking about. What volume were you at?


It does kinda, but I want a new one anyway..

 

Actually, it doesn't matter if the switch is set to Line, MM or MC for listening to the DAC > Headphone, since they are all by-passed. & why would I need to switch back to Line if I have a turntable connected to the phono in?

 

And, mine was humming/pulsating extremely loud with the volume set to "0"..

 

post #28 of 38
Quote:
Originally Posted by rabor View Post

Actually, it doesn't matter if the switch is set to Line, MM or MC for listening to the DAC > Headphone, since they are all by-passed. & why would I need to switch back to Line if I have a turntable connected to the phono in?

 

Oh you're right.

 

It would only matter if you would be using the GT40 as an amplifier connected to something else than a moving magnet or cartridge... or so I think it would matter, maybe it would just play but not loud enough.

post #29 of 38
Quote:
Originally Posted by rabor View Post

It does kinda, but I want a new one anyway..


How do you like your GT40? :P Can you compare it with previous headphone amplifiers and DACs you've owned in the past, or still own? Have you noticed some synergy with headphones others than Grados (I could talk you about the GT40 and the Grados all day long already because those are really the only things that I own, lol).

 

I don't think the GT40 is is the best in any category, like I said earlier or in another thread, but my expectations before I received it were reasonably low and I was positively surprised by everything it could do. I think it performs fairly well, as long as it doesn't fail like yours did. I listen to it all the time and it sounds better than using directly my laptop or my mp3 player, so it's a win for me. But I don't have money or space to own anything bigger at the moment, and that's also why I'm not too wise about headphone amps and DACs, I just haven't interested myself to them yet.

post #30 of 38
Thread Starter 

Sorry for bumping this ancient post but I'm curious to know, as life has gone on, has anyone else experienced the GT40 yet?

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