CHORD ELECTRONICS DAVE
Aug 31, 2016 at 6:04 PM Post #4,472 of 25,842
I have a question which may sound silly,
but I like to be in the dark when listening to music,
so I never bought any of the Hugo, Hugo TT, etc. because of these lights that turn on.
It would irritate me terribly and deprive me from any pleasure.
So now my question:
does the Dave have any such of these lights
or any bright LED which would emit a lot of light (e.g. could be a nuisance in a dark room)?
 
Aug 31, 2016 at 6:09 PM Post #4,473 of 25,842
I have a question which may sound silly,
but I like to be in the dark when listening to music,
so I never bought any of the Hugo, Hugo TT, etc. because of these lights that turn on.
It would irritate me terribly and deprive me from any pleasure.
So now my question:
does the Dave have any such of these lights
or any bright LED which would emit a lot of light (e.g. could be a nuisance in a dark room)?


As per the manual you can choose display option 4 which turns the display off after a brief time with no interaction with the unit. This is the setting I typically use.
 
Aug 31, 2016 at 7:09 PM Post #4,474 of 25,842
  As per the manual you can choose display option 4 which turns the display off after a brief time with no interaction with the unit. This is the setting I typically use.

 
Thank you.
 
I downloaded the manual,
it mentions a single headphone output (jack), do you connect the Utopia there?
 
Can you use the 2 XLR-3 outputs, which according to the manual are specific for headphones, for connecting a headphone?
 
It seems a pity that for such a price it does not have a XLR-4 headfphone output,
if we are not supposed to connect it to a headphone amp.
 
Aug 31, 2016 at 7:10 PM Post #4,475 of 25,842
  I have a question which may sound silly,
but I like to be in the dark when listening to music,
so I never bought any of the Hugo, Hugo TT, etc. because of these lights that turn on.
It would irritate me terribly and deprive me from any pleasure.
So now my question:
does the Dave have any such of these lights
or any bright LED which would emit a lot of light (e.g. could be a nuisance in a dark room)?

 
I'm the same way, aside when I had a tube amp.  I was good with that light and the city scape.  
 
Dave, with the screen set to turn off, of basically totally dark.  There seem to be some internal LED's that can shine through a little bit from above the screen but you have to look to see it.
 
Aug 31, 2016 at 7:12 PM Post #4,476 of 25,842
   
Thank you.
 
I downloaded the manual,
it mentions a single headphone output (jack), do you connect the Utopia there?
 
Can you use the 2 XLR-3 outputs, which according to the manual are specific for headphones, for connecting a headphone?
 
It seems a pity that for such a price it does not have a XLR-4 headfphone output,
if we are not supposed to connect it to a headphone amp.

 
DAVE is a single ended DAC.  A 4 pin XLR on the front doesn't make sense.
 
Aug 31, 2016 at 7:16 PM Post #4,477 of 25,842
  I don't have my DAVE yet, but I've auditioned one, twice, before purchasing. Have you auditioned one with your headphones plugged right into the DAVE?
 
I'm a solid state kind of guy, and I have my favorite headphone amp: the SPL Auditor. I've tried many, many HP amps, but I keep coming back to the Auditor. It is hands down the best solid state amp I have ever heard.
 
Then I auditioned the DAVE and plugged right into the headphone jack with my HD800s. I was amazed at how wide and deep the sound was, having my single-ended HD800s, sound as if I were running my cans with balanced 3-pin XLRs. The effect was simply stunning. I have read, somewhere in these 299 pgs, that the way the headphone section is implemented in the DAVE is very sophisticated, unlike any other headphone amp, which will actually optimize the DAVE to the fullest. No digital glare that I heard...in fact, quite the opposite.
 
Maybe somebody in here knows a bit more about what I was reading about DAVE's headphone output?
 
Anyway, when I wanted to see how the DAVE sounded with my Auditor, after listening to the DAVE alone, I found the sound coming through my Auditor to be very odd. Not quite "flat," but not near as lively and realistic as it was plugging right into the DAVE. Now, this is an HP amp that I have auditioned scores of DACs with, to great effect The Auditor usually brings out the best in a DAC, from a strict solid state standpoint. Not so with the DAVE, though. I wonder why that is? It's not a rhetorical question. No, I really wonder why that is.
 
I have not heard the headphone section on the Hugo TT, so I wouldn't know...but I thought the headphone section in the Hugo sounded a bit pinched, when it came to what I was used to with the Auditor.
 
Just my experience. Take it with a grain of salt. 

 
That's a fascinating story, and I'm glad to be confirmed.
 
I think it's not the Hugo's headphone section which is to be blamed, it's simply the Hugo's sonic signature that may not entirely harmonize with certain headphones. An amp in the signal path will certainly make the over-all sound more forgiving (to both down- and upstream flaws).
 
Hugo is the most 'airy' of the Chord DACs in its tuning.

 
I agree. It's slightly treble-friendlier than the DAVE. One (virtual) click on my X5 II's equalizer fixes the issue (well: with respect to the setting for DAVE). I wouldn't use an amp for that.
eek.gif
 
 
Aug 31, 2016 at 7:34 PM Post #4,478 of 25,842
Thank you.

I downloaded the manual,
it mentions a single headphone output (jack), do you connect the Utopia there?

Can you use the 2 XLR-3 outputs, which according to the manual are specific for headphones, for connecting a headphone?

It seems a pity that for such a price it does not have a XLR-4 headfphone output,
if we are not supposed to connect it to a headphone amp.


Yes, I use the headphone jack on the DAVE.

The SE configuration of the DAVE (and all Chord DACs) does not require balanced output to perform extremely well. The measurements prove this. Balanced output is on the DAVE for convenience, not sq improvement. There are many posts from Rob on the subject, and I would suggest reading through 'all posts' by Rob for explanations. It's a very worthwhile pursuit if such things are interesting to you. Here's a little on balanced:

http://www.head-fi.org/t/766517/chord-electronics-dave/195#post_11772205

Component count is very important for transparency. Doubling the number of parts in the direct signal path does degrade depth perception and detail resolution.

But there is another problem with balanced operation. Imagine a balanced differential in, differential out amplifier. The input stage is normally a differential pair (maybe cascoded) with a constant current source. Now the input stage is free to move up and down to accommodate the common mode voltage - but the input stage common mode impedance is non linear, and if the common mode voltage has a signal component (it always will have due to component tolerances) then this will create a signal dependent error current, thereby generating distortion. Unfortunately, the negative feedback loop of the amplifier can't correct for this distortion as it can't see the error on the summing nodes. So there will always be a limit to the performance. With SE operation, this problem does not occur, as the differential input stage is clamped to ground.

Now DAC designers are well aware of this - that's why all high performance DAC's use two single ended I to V converters from the current OP of the DAC's, then use a differential to SE converter to create the voltage OP. There are other reasons for doing this as well, as the DAC requires a very low impedance virtual ground for low distortion, and you can only get this using dual SE amps - another problem is RF and its much easier to decouple SE than differentially - this in turn creates a lot more noise floor modulation, making it sound less smooth.

But for me the most important is transparency. I had an amp that had two modes - differential or SE - listening in balanced mode flattened the sound stage depth dramatically,and it sounded harder, less smooth. That said, there are circumstances when balanced operation can be better than SE, for example when you are looking at connecting a pre-amp to a power amp, and what is best depends upon particular circumstances. In short, if SE operation is noisy, try balanced.

Rob 



Also, don't connect balanced headphones to the balanced output of the DAVE. Straight from the source:

http://www.head-fi.org/t/766517/chord-electronics-dave/840#post_12124924

Categorically do not do this. The balanced drive has insufficient current drive and is intended to drive power amps only.

Dave can drive the HE1000 with ease - they are rated at 90 dB 1mW 33 ohms. Dave will give 1.4W into 33 ohms that translates to ear damaging 121 dB SPL with the HE1000.

Moreover distortion is virtually identical with a 33 ohm load - that is hundreds or thousands of times smaller than the best headphone amps. Unless you like the sound of distortion, and prefer reduced transparency, and no depth, don't use an external amp.

Rob



http://www.head-fi.org/t/766517/chord-electronics-dave/1695#post_12355143

I am not listening....

Actually, production Dave now has short circuit protection resistors installed on the balanced XLR, so it absolutely won't drive headphones! It didn't have the current drive either for headphones too.

As to cross-feed - I prefer 3, its closer to loudspeaker perspective.

Rob
 
Aug 31, 2016 at 7:55 PM Post #4,479 of 25,842
I guess my broader question was, are the DAVE fans basically Chord-all-the-way, or do they feel the Chord DAC technology is the main point of genius here and in the Hugo series?

I use USB (AQ Diamond after a lot of experiments with other USBs). I also fussed a lot with interconnects and the amp power cable to get the sound I like [Stealth and Shunyata]. Thanks for the kind advice. [The source is a Windows PC using JRiver + Tidal.]
I do play with Jriver EQ sometimes (I have lots of curves stored), always to deal with glare, so I dip the upper mids to highs sometimes, just subtly, and tailored to each headphone. No EQ with Tidal though.


Right, but have you tried adding say an Audioquest Jitterbug to filter the noisy USB output from your PC before connecting your AQ Diamond? If you did, did the Jitterbug remove the digital glare you didn't like? If I play from my laptop, it's not plugged in to reduce noise and optimize the galvanic isolation. My "desktop" is a CAPSv3 Carbon which has a SOTM USB card that has noise filtering for the USB output and I use a separate linear power supply to power the USB port.
 
Sep 1, 2016 at 12:12 AM Post #4,480 of 25,842
Right, but have you tried adding say an Audioquest Jitterbug to filter the noisy USB output from your PC before connecting your AQ Diamond? If you did, did the Jitterbug remove the digital glare you didn't like? If I play from my laptop, it's not plugged in to reduce noise and optimize the galvanic isolation. My "desktop" is a CAPSv3 Carbon which has a SOTM USB card that has noise filtering for the USB output and I use a separate linear power supply to power the USB port.

 
Hmmmm...but either galvanic isolation is galvanic isolation, or it isn't...and if it is, it is there is supposed to be no worry outside interference, yes? At least that's what I've always believed.
 
I don't have my DAVE yet, and in auditioning I didn't have my iUSB 3.0 with me, but in theory I wouldn't need it for a galvanically isolated DAC if the science is all what it's cracked up to me; so, why the jitterbug, or a Uptone Regen, or the iUSB 3.0?
 
Or maybe I'm totally missing something (which is well within the realm of possibilities).
 
Sep 1, 2016 at 12:46 AM Post #4,481 of 25,842
Hmmmm...but either galvanic isolation is galvanic isolation, or it isn't...and if it is, it is there is supposed to be no worry outside interference, yes? At least that's what I've always believed.

I don't have my DAVE yet, and in auditioning I didn't have my iUSB 3.0 with me, but in theory I wouldn't need it for a galvanically isolated DAC if the science is all what it's cracked up to me; so, why the jitterbug, or a Uptone Regen, or the iUSB 3.0?

Or maybe I'm totally missing something (which is well within the realm of possibilities).


http://www.head-fi.org/t/766517/chord-electronics-dave/3435

Rob Watts previously addressed this issue/question in the above post.
 
Sep 1, 2016 at 1:53 AM Post #4,482 of 25,842
   
I don't have my DAVE yet, but I've auditioned one, twice, before purchasing. Have you auditioned one with your headphones plugged right into the DAVE?
 
I'm a solid state kind of guy, and I have my favorite headphone amp: the SPL Auditor. I've tried many, many HP amps, but I keep coming back to the Auditor. It is hands down the best solid state amp I have ever heard.
 
Then I auditioned the DAVE and plugged right into the headphone jack with my HD800s. I was amazed at how wide and deep the sound was, having my single-ended HD800s, sound as if I were running my cans with balanced 3-pin XLRs. The effect was simply stunning. I have read, somewhere in these 299 pgs, that the way the headphone section is implemented in the DAVE is very sophisticated, unlike any other headphone amp, which will actually optimize the DAVE to the fullest. No digital glare that I heard...in fact, quite the opposite.
 
Maybe somebody in here knows a bit more about what I was reading about DAVE's headphone output?
 
Anyway, when I wanted to see how the DAVE sounded with my Auditor, after listening to the DAVE alone, I found the sound coming through my Auditor to be very odd. Not quite "flat," but not near as lively and realistic as it was plugging right into the DAVE. Now, this is an HP amp that I have auditioned scores of DACs with, to great effect The Auditor usually brings out the best in a DAC, from a strict solid state standpoint. Not so with the DAVE, though. I wonder why that is? It's not a rhetorical question. No, I really wonder why that is.
 
I have not heard the headphone section on the Hugo TT, so I wouldn't know...but I thought the headphone section in the Hugo sounded a bit pinched, when it came to what I was used to with the Auditor.
 
Just my experience. Take it with a grain of salt. 

 
Dave does indeed have a unique amplifier section - it is actually a 2nd order analogue noise shaper (a conventional amp is a first order noise shaper).
 
The reason I do this is two fold - firstly, whenever you load a headphone amp you get more distortion, and its audible and all amplifiers suffer from this. By using a 2nd order noise shaper approach allows me to eliminate this problem - when I load the outputs there is zero change in distortion (apart from a small increase in 2nd harmonic). This means when you load the OP, there is no change in sound quality (all other amps harden up and to mask this they add a lot of 2nd harmonic to fatten the sound up).
 
The second reason this is done is high frequency distortion. All conventional amplifiers have higher distortion as frequency rises, and this has important SQ consequences, in terms of making things sound hard and un-musical. This is due to insufficient feedback available at high frequencies with poor open loop distortion. Now the distortion with modern high performance op-amps is down to the output stage - and that's one reason why all my DAC's have discrete OP stages, so I can eliminate this weakness. But my second order system has excellent open loop distortion performance plus no HF feedback problems too. A indicator of this is the gain bandwidth product - the best audio op-amps are 100 MHz, but with Dave it is 1 GHz.    
 
You can see this HF distortion problem with the 19k/20k test. All DAC's make a mess of this but Dave has the lowest distortion of any other DAC using this test:
 

 
This level is actually the residual performance of the APX555, so Dave is probably much better than this (one reason why Davina is happening - I need better ADC's to measure).
 
By using the second order approach does not affect transparency - it is still a single global feedback path, so the effective number of passive components is the same as before.
 
Rob 
 
Sep 1, 2016 at 3:24 PM Post #4,483 of 25,842
I would like to add another argument regarding "parts porn". First, it is the result that matters, and the Dave delivers (I own Hugo and Mojo, but cannot afford the Dave, but listened to it and compared it to Mojo). Second, the more parts and soldering points, the more parameters need to be kept in check. It is inevitable, that variation of such equipment is much larger within a production series, and that they age faster compared to smart designs with fewer components and more integrated design. 
 
Sep 1, 2016 at 5:30 PM Post #4,484 of 25,842
I would like to add another argument regarding "parts porn". First, it is the result that matters, and the Dave delivers (I own Hugo and Mojo, but cannot afford the Dave, but listened to it and compared it to Mojo). Second, the more parts and soldering points, the more parameters need to be kept in check. It is inevitable, that variation of such equipment is much larger within a production series, and that they age faster compared to smart designs with fewer components and more integrated design. 
Point well made. However I would like to add that the number of active working transistors within Dave is quite possibly several billion more than in some typically flamboyantly componented but possibly rather dated alternative designs.
 
Sep 1, 2016 at 7:51 PM Post #4,485 of 25,842
If you allow me, I have another dumb practical question related to this single headphone output.
 
My situation (I assume it is not unusual among audiophiles) is that I have a number of headphones hanging around my desk,
and while I am behind my computer trying out different kinds of music,
I like to quickly switch headphones accordingly (e.g. bright vs dark, or better for vocals vs better for punch, etc.),
and I don't like to unplug them each time.
So I usually have the lowest impedance headphones connected to various ouputs (XLR-4, 2xXLR-3, jack) of my headphone DAC-amp
and other headphones to the outputs of headphone amp.
To switch headphones, I just hang back the one I had, turn the output selector knob for the headphone I want, grab it, and voilà...
(besides this simply prevents the jacks and the plugs from being exposed to dust), 
 
How do you do then with the single output of the Dave?
Still adding an amp with many outputs or bothering with plugging out and in 
(and possibly trading an XLR-to-jack adaptor between the headphones) ?
 

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