Mr White's "Opus", designing a simple balanced DAC

[jean-paul]

Originally posted by pinkmouse
Quite possibly true, but a lot of kit doesn't have an electrical out these days.

That gear does not deserve a well designed DAC...

Really , there is no affordable substitute for SPDIF over coax that is better ( yet ). Todays optical interfacing for consumer devices certainly is not. In all cases I2S is the best way to go and build the DAC in the device whose data it will convert. What is the use for converting 24 bit 96 kHz data with a jittery interface ?

Maybe it is possible to provide some extra pads for mounting such a dreaded device instead of the BNC connector for those that want to go optical anyway ?!

[BrianDonegan]

So, I am thinking of using Elna RFS Audio Grade caps in the kits. Anyone have experience with them?

http://www.elna-america.com/products...es/AL/RFSe.pdf

All ELs are 10uF, I will be using the 35V version (overkill, but readily available).

[EDIT] Interesting translation in that datasheet...

[jean-paul]

Industrial low ESR electrolytics with a known good reputation are also a good choice in terms of price/performance. Some also sound equal or better but my experience with DIY dates from Silmic I. I've heard gear with Silmic II though and it sounded good. What about using Panasonic FC low ESR for decoupling the chips and using the Elna Silmic II caps in the signal path ?

For the signal path I would recommend either Wima MKS film caps with 5 mm pitch ( probably 4.7 or 6.8 uF 50V ) or Black Gate N series 10 uF 50V bipolar electrolytic caps if it have to be boutique parts. The latter sound very good but have a pricetag.

[BrianDonegan]

Well, these are only $0.09 each, so not sure I would call them boutique (in price anyway). Another option would be the tried and true Panasonic FC...

[pinkmouse]

Have you considered the Rubycon ZA or ZLs?

[jean-paul]

Originally posted by BrianDonegan
Well, these are only $0.09 each, so not sure I would call them boutique (in price anyway). Another option would be the tried and true Panasonic FC...

Did you read the datasheet ?

[BrianDonegan]

No good source for Rubycon in the US. Could go through Farnell, but have to pay VAT and shipping.

I did read the datasheet. I actually thought it was kinda funny. But, I though people might like these more. BTW, I did say "price wise."

I was actually hoping to use Panasonic FM (ultra-low imped), but they don't have a 10uF.

[jean-paul]

Then stay with the Silmic II caps. They are quite inexpensive as I see now and they're good quality too. Do you want only one brand and type electrolytics in the kits ? Otherwise I'd still recommend using low ESR caps like Pana FC or FM for decoupling the Wolfson chip.

[BrianDonegan]

Perhaps for the beta I will get some of each, and we can try them out.

[Russ White]

Notice the output caps have 2.5 and 5mm pitch.

Also I used the digital input scheme Jean-Paul pointed me to.

Cheers!
Russ