[luvdunhill]

please don't post in this thread Tom until you have the kits ready, ya tease!

just kidding

Assembling Tom's kit is like a day at the spa for me... none of these projects that drag out years and years, they come together in a few hours and just seem to work... no searching for parts at Mouser, only trying to find them on the floor occasionally

 

[Juaquin]

I'm waiting on 2 kits myself (one for my desktop, one for my upcoming all-in-one amp). Someone call China and tell them to hurry up on those PCM chips.

 

[ziplock]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif ... and I was wrong (again?) - the clearance height is 10.5mm, not 11.2mm. Again, please accept my apology - the BOM has been corrected with caps that will fit.

No worries Tom.

You fixed it and I'm probably one of few who used those caps.

Anyway, rock on! Time to have a nice listening session with the mighty Grub.

 

[sandbasser]

A quick question about the BOM (the newest)...

Are the Mouser and DigiKey parts equal or should the DigiKey parts be preferred???

Thanks,

 

[cobaltmute]

I would say that the only "preferred choice" from the Digikey BOM is the C1, C5, and C15 caps. These were chosen as nice large filtering/rail caps that fit the CableDAC case.

Aside from that, the parts were chosen to be equal and available.

 

[ovrclkd]

Put a second one together and Win 7 recognized it straight away.
I'll install it in the MOSFET MAX tomorrow.
I'd really like to piggy back the Bantam & Grub in there for some on the fly side by sides ....

I checked the "non working" one and everything looks identical to the 2nd ...
I've got something screwed up or fried but it's not visible.

The third will be a cable version .... I'll post after I marry the Grub to the MAX

 

[tomb]

Quote:

Originally Posted by ovrclkd /img/forum/go_quote.gif Put a second one together and Win 7 recognized it straight away. I'll install it in the MOSFET MAX tomorrow. I'd really like to piggy back the Bantam & Grub in there for some on the fly side by sides .... I checked the "non working" one and everything looks identical to the 2nd ... I've got something screwed up or fried but it's not visible. The third will be a cable version .... I'll post after I marry the Grub to the MAX

Congrats on getting the 2nd one to work! Good job!

I don't know - you might be able to piggyback them with some tall standoffs for the board on top. Then simply run the 2nd one's leads to where you have the RCA inputs at the relay punch-down block. Then as you say, you could switch one from the other.

However, you'd have to find something that would run in multiple instances on your PC so that you could avoid switching back and forth with sources in the software, too. I use Foobar and it won't let me run anything but one instance, so I have to switch the sources in the software, anyway.

I've been switching the physical sources on mine already because I use the grubCableDAC version. I have that connected through the RCA jacks and then have an onboard Bantam. So, the physical switch makes the change easily enough. It's just a hassle to stop everything and switch it in the software, too. Maybe I'm not understanding something when it comes to the software, or perhaps there's another media player that will run in several instances while choosing different sources for each one? Actually, Foobar is more convenient than most, because it lets you select the source in the software. Many other media players force you to make the change through the operating system, which is a much bigger hassle.

 

[GeWa]

Any idea when kits will be available?

Regards

 

[tomb]

Quote:

Originally Posted by GeWa /img/forum/go_quote.gif Any idea when kits will be available? Regards

Well, I've been saying the last week of April to the first week of May. As it turns out, though, I'm going out of town during the first week of May - so maybe the 2nd week?

 

[ovrclkd]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Congrats on getting the 2nd one to work! Good job! I don't know - you might be able to piggyback them with some tall standoffs for the board on top. Then simply run the 2nd one's leads to where you have the RCA inputs at the relay punch-down block. Then as you say, you could switch one from the other. However, you'd have to find something that would run in multiple instances on your PC so that you could avoid switching back and forth with sources in the software, too. I use Foobar and it won't let me run anything but one instance, so I have to switch the sources in the software, anyway. I've been switching the physical sources on mine already because I use the grubCableDAC version. I have that connected through the RCA jacks and then have an onboard Bantam. So, the physical switch makes the change easily enough. It's just a hassle to stop everything and switch it in the software, too. Maybe I'm not understanding something when it comes to the software, or perhaps there's another media player that will run in several instances while choosing different sources for each one? Actually, Foobar is more convenient than most, because it lets you select the source in the software. Many other media players force you to make the change through the operating system, which is a much bigger hassle.

Just put the third Grub together which I'll finish with RCA jacks for output. No problems, Win 7 said hello as soon as I connected the USB cable (I drilled a 1/4" hole and used a 5mm led grommet in the hammond case for a chafe guard.)

I decided to dig back into the first one and found a bad joint at U2. I resoldered it, Windows "saw" it but failed to recognize it. Both U2 and R4 are RED HOT and I have 1.4 volts at 3V3 now.. Your wisdom?

Still haven't opened the MAX back up ... I was handed the honey do jar and it was a good day to get caught up and "bank" some time.

 

[tomb]

Quote:

Originally Posted by ovrclkd /img/forum/go_quote.gif <snip> I decided to dig back into the first one and found a bad joint at U2. I resoldered it, Windows "saw" it but failed to recognize it. Both U2 and R4 are RED HOT and I have 1.4 volts at 3V3 now.. Your wisdom?</snip>

My wisdom says ask cobaltmute.

Let's see what he says when he sees it.

 

[cobaltmute]

If R4 is getting hot, I suspect a problem with X1, C2 or C1. R4 is an 1/8W part. At 3.3V and 4ma (for the Digikey part), it should be passing 0.012W, which is well below what R4 should be handling.

Possible bridge on X1,C2 or C1? or you've fried X1?

 

[ovrclkd]

Quote:

Originally Posted by cobaltmute /img/forum/go_quote.gif If R4 is getting hot, I suspect a problem with X1, C2 or C1. R4 is an 1/8W part. At 3.3V and 4ma (for the Digikey part), it should be passing 0.012W, which is well below what R4 should be handling. Possible bridge on X1,C2 or C1? or you've fried X1?

Thanks for the quick reply.... YOU WERE CORRECT!

One of my "blobs" made its way to the casing around X1 causing a bridge.

I am now the VERY proud owner of 3 working GrubDAC's, no easy feat for me ....

Now the best part, I connected the FIRST one to the MOSFET MAX and the difference in SQ between the Grub & Bantam is nite and day.
The GrubDAC really brought the best out in the MAX. If I was asked to use one word to define the difference between a Bantam & GrubDAC it would be "Clarity". The Grub adds a new dimension and refinement to the music.
Once again the reference file was Fleetwood Mac's "Rumours" album listening thru Grado 325i's.

Thanks again for the troubleshooting tips!

Time to update the MAX thread ...

~Jay R.

 

[mfaughn]

Hi all,

I built a grubdac many months ago and it never worked. I suspect that the dac chip is bad as I can detect no untoward voltages and no shorts.

I have all the parts on hand to try again (actually to build a bunch of them) but I have been waiting for months to get the DAC chips. Does anybody know of a source for these things? I am about to go with whatever random place gives me a reasonable quote from some of the chipfinder websites (if even that works). TI is supposed to be sending me samples but they keep revising their delivery estimate and it is now into August. I am hoping to get some before May 23.

Thanks,
Michael

 

[cobaltmute]

If you look at Mouser, they are scheduled for a large qty of both the PCM2706 and PCM2707 over the next few months.

I would say patience is a virtue and to wait for these supplies. You never know what you might get or have to pay otherwise.