[simplethings]

First, thanks for a great little DAC - really handy size and a great price. I built a GrubDAC a few months ago and have been very happy with it as my on the road source. It's setup with the on-board miniUSB and I managed to squeeze a mini-jack socket in Hammond enclosure as well making it nice and self contained:
 

 
I'm considering tweaking as per the GrubDAC Tweaks and swapping out the three polymer caps at C1, C5 & C15 for three Nichicon UKW1A471MEDs (as well as putting three holes in the Hammond box to allow the caps to poke through). Has anyone tried swapping the caps out and if so, was it worth doing (aka would you do it again if you built another ) ?
 

 

[particleman14]

I've used those caps before but only because the polymers were sold out one time..  I don't notice any difference other than the nichicons won't fit into the small hammond box without some reworking..  why would you want the caps sticking out of that neat enclosure?

 

[simplethings]

If the noise reduction was audible I'd happily have 3 caps sticking out of the top. If the difference is negligible well, there is no reason to ruin a poor little hammond box. What I'll perhaps do, as there hasn't been much response on this topic, is given the GrubDAC some good listening over the next month, swap the caps and report back. 

 

[DingoSmuggler]

Quote:

If the noise reduction was audible I'd happily have 3 caps sticking out of the top. If the difference is negligible well, there is no reason to ruin a poor little hammond box. What I'll perhaps do, as there hasn't been much response on this topic, is given the GrubDAC some good listening over the next month, swap the caps and report back. 

The noise-floor on my grubDAC is not noticeable.
You could always fit the standard caps, and retro-fit the larger electrolytics later if you're not happy.

 

[cobaltmute]

Quote:

If the noise reduction was audible I'd happily have 3 caps sticking out of the top. If the difference is negligible well, there is no reason to ruin a poor little hammond box. What I'll perhaps do, as there hasn't been much response on this topic, is given the GrubDAC some good listening over the next month, swap the caps and report back. 

You shouldn't hear much (if any) of a difference.  This is one of those tweaks, that at an absolute level will do something, but may not make an audible difference.
 

 

[TheLaw]

Hey guys,
 
Just finished building my GrubDAC and it works. Good sound...However I have one issue. I think that has to do with my computer but I just want to see if anyone knows how to do this?
 
I want to be able to control system volume via the slider on the bottom of the taskbar. I'm running Windows 7 64-bit. Currently moving the slider does nothing. I can only change the volume if I right click and go to mixer and change each individual programs audio, but I want to be able to change all of them at once, like I am familiar with. Also, hitting mute doesn't do jack sh--t.
 
I know you might tell me that I should not be using windows for volume control, however, this is a shared computer and I have to have it this way.
 
Any ideas on how to configure it?
 
 

 

[tomb]

Quote:

Hey guys,
 
Just finished building my GrubDAC and it works. Good sound...However I have one issue. I think that has to do with my computer but I just want to see if anyone knows how to do this?
 
I want to be able to control system volume via the slider on the bottom of the taskbar. I'm running Windows 7 64-bit. Currently moving the slider does nothing. I can only change the volume if I right click and go to mixer and change each individual programs audio, but I want to be able to change all of them at once, like I am familiar with. Also, hitting mute doesn't do jack sh--t.
 
I know you might tell me that I should not be using windows for volume control, however, this is a shared computer and I have to have it this way.
 
Any ideas on how to configure it?
 
 

Well, I'm hoping cobaltmute will respond to this, if he has time.
 
However, you know what we're going to tell you - adjusting the volume control through the OS on a PC actually reduces the bits in the music stream.  I'm not sure I understand your situation with a "shared" computer.  Maybe you need to load a player that will identify a separate sound source such as Foobar.  That way, it doesn't matter what the OS is using as the sound card - you can select the GrubDAC independently.
 
In any event, if you have a "shared" computer, it doesn't seem to me a very considerate situation to have your GrubDAC assume the default soundcard status of the OS.  Chances are, that's what's getting mixed up in the volume control, because you shouldn't have to go in and adjust the mixer.
 
Maybe you could tell us more about your situation and we could suggest a better work-around?
 
 

 

[TheLaw]

Well I'm on a computer that is shared amongst people in my household. So I can't just suddenly have the volume slider not work...
 
The problem confuses me a lot because traditionally the volume bar with control all of the programs volume at once. In the mixer you can set each individual program to have lower or higher volume limits. However, in my case, I have all of the applications set to maximum volume as well as the main volume slider. You would assume moving the bar up and down would proportionally reduce or lower the volumes of all applications, however, sliding the volume bar does nothing! Sure, I can control volume, but only if I go into the mixer and change each individual program. I disconnected the DAC and switched back to onboard sound. Now the volume slider works fine.
 
So if I move the main slider to volume 5, it will be the same volume even if I move it to volume 50.
 
Graphically, the volume slider works fine. The animations it shows with the graphic visualizer (VU meters) correspond with the change in volume, but the sound does not.
 
Does not anyone else have this problem? I really find that hard to believe...
 
Thanks.

 

[tomb]

Quote:

Well I'm on a computer that is shared amongst people in my household. So I can't just suddenly have the volume slider not work...
 
The problem confuses me a lot because traditionally the volume bar with control all of the programs volume at once. In the mixer you can set each individual program to have lower or higher volume limits. However, in my case, I have all of the applications set to maximum volume as well as the main volume slider. You would assume moving the bar up and down would proportionally reduce or lower the volumes of all applications, however, sliding the volume bar does nothing! Sure, I can control volume, but only if I go into the mixer and change each individual program. I disconnected the DAC and switched back to onboard sound. Now the volume slider works fine.
 
So if I move the main slider to volume 5, it will be the same volume even if I move it to volume 50.
 
Graphically, the volume slider works fine. The animations it shows with the graphic visualizer (VU meters) correspond with the change in volume, but the sound does not.
 
Does not anyone else have this problem? I really find that hard to believe...
 
Thanks.

I've got Windows 7 - although I'm not running 64-bit (unfortunately).  However, it does the same thing with me.  Netflix runs in Internet Explorer and a Netlfix movie is not affected by anything but the separate mixer for "Internet Explorer."  Likewise, if I play music with the Windows Media Player, the only thing that controls the volume is the Windows Media Player volume in the mixer.
 
It appears that Windows 7 recognizes another property under the sound controls - that of default "Communication Device."  If you change one playback source to another, the default "Communication Device" may remain with the disabled sound device.  I tried changing that, too, to the GrubDAC and it had no effect on the overall volume slider issue.
 
IMHO, this appears to be a quirk with Microsoft "improvements" that were incorporated in Windows 7.  (I once called one of their updates the worst virus I ever experienced.)  I seriously suspect that you're going to get this phenomenon with many DACs. After all, the PCM2706/7 is fairly ubiquitous as a USB interface, not just with the GrubDAC.  I guess more accurately, one should state that TI's PCM2706/7 has not caught up fully with the new features in Windows 7.  'Course, the way this usually works is that Microsoft sits back and waits for the mfrs to pay them up front for insight into the latest OS.  If not, then the rest of us suffer for several years with drivers that are a bit buggy until they get re-written.  I still have a PC running Windows XP because it's the only thing compatible with my M-Audio Transit.
 
You still didn't mention what you're trying to access, but honestly, the Foobar solution is ideal and I've never had an issue.  The Netflix volume control and the Windows Media volume control all work independently and operate just fine with the GrubDAC as the default device.  However, the volume control to my DVD interface (CybeLlink Power DVD) does not work independently.  So granted, it's inconsistent.
 
Still, all you have to do is select "mixer" and one of the controls will always work.  All you need do is to remember to set it back when you leave, right?  Actually, you don't even have to do that, because the volume control for the device you were using will disappear when it's not running.
 
Not sure that fully answers your question, but it's the best I can do at the moment.

 

 

[Avro_Arrow]

Windows 7 volume control behaves differently to previous versions.
PCM270x have been redesigned as a result. See here:
http://www.ti.com/lit/an/sbfa019/sbfa019.pdf
 
It might not have anything to do with your problem, but then it might...

 

[TheLaw]

So can it would be a pain in the dupa, but can I solder on a PCM2706C?

 

[tomb]

Quote:

Windows 7 volume control behaves differently to previous versions.
PCM270x have been redesigned as a result. See here:
http://www.ti.com/lit/an/sbfa019/sbfa019.pdf
 
It might not have anything to do with your problem, but then it might...

No, that's a good catch - it has everything to do with the problem.

Unfortunately, the "C" version of the PCM2706/7 is still in "Preview" mode, only, at TI.  ("PREVIEW: Device, tool, or software has been announced but is not in production. Samples may or may not be available.")  That means it can't be ordered in volume at Mouser/DigiKey and we can't put it in GrubDAC kits.
 
Quote:

So can it would be a pain in the dupa, but can I solder on a PCM2706C?

 
See the above.  You can try to get a sample from TI.  (This is certainly a legitimate use of the sample program!)  Let us know how it works out.  I'll try to do the same when I get a chance.
 
Isn't Microsoft wonderful?

 
 

 

[TheLaw]

Ugh...Now I kind of don't like W7 anymore. Damnit. Colbaltmute, I think you should add that to the GrubDAC page: that it may not work too well in W7. It will work...just not as  you might expect.
 
Hmm....replacing that PCM might be a pain in the arse since everything's already in place and I dont have hot air rework.
 
Plus TI might not be nice. Grr.

 

[tomb]

Quote:

Ugh...Now I kind of don't like W7 anymore. Damnit. Colbaltmute, I think you should add that to the GrubDAC page: that it may not work too well in W7. It will work...just not as  you might expect.
 
Hmm....replacing that PCM might be a pain in the arse since everything's already in place and I dont have hot air rework.
 
Plus TI might not be nice. Grr.

It doesn't matter - samples aren't even available: "Contact your distributor."  That typically means very long lead times and high quantities required.
 
I wouldn't blame TI, though, at least they're trying to respond to the change.  It's Microsoft that did it.  Seems to me any USB device with sound will be similarly affected.
 
 

 

[TheLaw]

Oh I'm not blaming TI. Even though TI has huge market share...whether they got there fairly or not...I don't know, I like them.
 
Just wanted to comment on the actual GrubDAC. I'm using this hooked up to a homemade power chipamp. About 50Wx2 + 50Wx1 (sub). Bass is so much more punchy. I can't really believe it. I wouldn't say I'm stunned by new things in the music popping out at me, but it is much cleaner sounding than the onboard sound, which is decent to start with. So a bass drum actually feels/sounds like a real bass drum hit. I'm not going to use the fancy words I see some of you guys use...but it really does sound better.