[dviswa]

Alf and everybody,

I am back from my vacation. Hope you all had a nice holidays and new year.

I had forgotten that with the DAC connected, my machine would not start because of the USB issues I had. This frustated me enough to do some debugging. Because my setup is option B - Wall wart powered, thought D+, D- and GND, were all the connections needed for this. I removed VBUS connection and DAC was still working and my USB issues were gone. The flashdrive came on, camera came on. Connecting VBUS back brought back all the issues, the flashdrive gets no power (because the LED does not come on) and quits. That brings up the question; Does VBUS need a jumper?

Regards,
Dinesh

 

[Clutz]

I know this is overkill, but I'm going to order the parts from parts connexion anyway, and they have a $25 minimum order so I figured - why not?

I'm thinking of going entirely with Blackgates C2, C4, CL, C4, C24 = 33uF 50V, Blackgate N series. For C6, 100uF, 6.3V, C7, 220uF, 6.3V, Blackgate NX.. But I have absolutely no idea what to do for C10/C14..?

(btw: I'm doing options A and B)..

Is this overkill to the point where it's bad? Should I just go with some Panasonics for most of the caps except CL, CR, C24? If I should, let me know ASAP so I can add them on to my order that I just made with digikey.

Thanks

 

[ble0t]

I'm not sure you'll see much difference using Blackgates everywhere aside from the coupling caps (CL, CR). I think what you're mainly after is low ESR, and pana FC's have very nice ESR measurements, so I think those would work just fine. I used OSCONs for everything except for C5, CR and CL as those have even lower ESR.

 

[dsavitsk]

For L and R, use the BG 4.7uF N series. For 24, how about an Os-Con. For the others, try BG standard or PK. The N series is not appropriate there. Hard to know if there will be any real benefit here, but it is only a couple of bucks.

 

[ble0t]

Also, in response to Alf's post, I did find something that may help out. I posted the links here in my thread concerning a PCM2704 design I'm working on.

 

[Clutz]

I'd get Oscons if I could get them from digikey, but they don't have any particularly good caps for output caps at digikey. I could order from Mouser, but delivery to Canada is extremely slow. So, this means I have to order from something like Parts Connexion or Welbourne Labs. Parts Connexion is in Toronto, ON, and I'm in Vancouver, BC, which means I won't have to pay any importing duties / brokerage fees, and my shipping fees will be a lot less than buying from Welbourne. Parts Connexion has a minimum of a $25 order, or you get a $5 handling fee, so I figured I might as well spend at least $25, since just getting the CL, CR, and C24 would bring me to $15 before shipping. It might jack the price up a bit- like to $30 - but if it's better, then I'll do it.. Otehrwise, I'll just go and tack on some Panasonic FMs or FCs (which are better here, FMs, righjt?) to my order to have some extras lying around in my kit.

 

[Clutz]

Quote:

Originally Posted by dsavitsk For L and R, use the BG 4.7uF N series. For 24, how about an Os-Con. For the others, try BG standard or PK. The N series is not appropriate there. Hard to know if there will be any real benefit here, but it is only a couple of bucks.

Okay, thanks. I figure I might as well put good quality parts in this, since it's not going to cost me a lot more to do that than put the cheaper alternatives - and I don't think I'll have the money to design and build a DaKiller level DAC for a while.. But I do plan on trying out yours dsavitsk.

 

[Clutz]

For C10/C14, it says medium ESR-- is it bad to use low ESR, or just that there isn't any benefit?

 

[Alf]

My suggestions:
* Use OSCONs 47uF 16V for C2, C4 if you can get them. If not, choose the biggest value and the lowest ESR (for example, Panasonic FM 120uF 16V).
* Do not populate C5 for option A.
* Do your own listening tests for CL/CR. Try different capacitors. You should be able to get away with 0.47uF. Therefore film capacitors could be an option – fitting them could be tricky but worth a try.
* Use either of Panasonics for the rest. FMs are meant to be better.

 

[Clutz]

So you think that using Panasonic FMs is preferable over BlackGates? i can get them, but they'd be a bit of a pain cause I'd have to make another order with digikey, and I just made an order.. I can't get Oscon 47uF 16V, but I can get 20V, which should fit, right? Do you think it'd be worth spending ~$20 on two 0.47uF auricaps? Or maybe some Orange Drops or Solens which I can easily source locally?

 

[Alf]

Quote:

Originally Posted by Clutz So you think that using Panasonic FMs is preferable over BlackGates? i can get them, but they'd be a bit of a pain cause I'd have to make another order with digikey, and I just made an order..

Panasonics are cheaper. I doubt one can hear any difference. If you placed an order already, there is no point to order FMs. Blackgates will do fine.


Quote:

Originally Posted by Clutz I can't get Oscon 47uF 16V, but I can get 20V, which should fit, right?

No, the 20V version would not fit. The board has space for a 6mm capacitor. Your choice of OSCONs is limited to SA 33uF 16V/20V, SC 33uF 16V, and SA 47uF 16V.

Quote:

Originally Posted by Clutz Do you think it'd be worth spending ~$20 on two 0.47uF auricaps? Or maybe some Orange Drops or Solens which I can easily source locally?

This depends on your ears and your budget. I would try local-sourced caps first.

 

[Clutz]

Quote:

Originally Posted by Alf Panasonics are cheaper. I doubt one can hear any difference. If you placed an order already, there is no point to order FMs. Blackgates will do fine.

Alright, then I'll get the blackgates.. or maybe order the parts to put together something like dsavitsk DAC from digikey, and try using some film caps sourced locally. I'll also try to find if I can find any other locally sourced OSCONs. I've never seen them at any of the local shops I've tried out, but I an look a bit further.

I'm still nervous about soldering the PCM2702E. I have a 40watt soldering iron, so maybe I'll pick up a higher quality 25 or 30 watt soldering iron this weekend.

 

[dsavitsk]

Quote:

Originally Posted by Clutz or maybe order the parts to put together something like dsavitsk DAC from digikey

Not meaning to thread crap -- if you build one of mine, I recommend getting the offboard version of the transformer. I am getting a bit of noise, mostly into amps with highish (100K) input impedence and I think that the transformer proximity is to blame.

Quote:

I'm still nervous about soldering the PCM2702E.

Don't be. It's not a big deal.

 

[dviswa]

Quote:

Originally Posted by Clutz I'm still nervous about soldering the PCM2702E. I have a 40watt soldering iron, so maybe I'll pick up a higher quality 25 or 30 watt soldering iron this weekend.

Radioshack 15W worked just fine for me. Not scaring you, but, You will put a few bridges across a few pins, nothing some Desoldering braid cannot fix.

 

[diablo9]

Quote:

Originally Posted by dviswa Radioshack 15W worked just fine for me. Not scaring you, but, You will put a few bridges across a few pins, nothing some Desoldering braid cannot fix.

one way to solder 1 side without any bridging is to:
flood each side with flux for both PCB and pins,
tin the iron with good amount of solder,
pull the iron through the pins in fast and steady speed.
solder on the iron will be "sucked" into the seam of pin and PCB,
this way you will never get bridge,
keep in mind that you need to "flood" the PCB with flux.

enjoy

Yishi