Soekris Dam Dac

[nige2000]

i have not been keeping up to date with the filters whats the good ones these days

[rickmcinnis]

The very latest one spzzzzrt posted is just enough better than the pair from about a week ago to be worth the trouble.

Can't wait to hear what happens with the new firmware and its expanded capabilities.

SOEKRIS says he will incorporate a polarity switch. Hope it will be easier to use than the one within JPlay.

Got my computer supply working - see post in that forum.

[nige2000]

The very latest one spzzzzrt posted is just enough better than the pair from about a week ago to be worth the trouble.

Can't wait to hear what happens with the new firmware and its expanded capabilities.

SOEKRIS says he will incorporate a polarity switch. Hope it will be easier to use than the one within JPlay.

Got my computer supply working - see post in that forum.

which forum ?
jplay or diyaudio

[rickmcinnis]

Had no idea he was posting on JPlay so did not realize I needed to be specific!

http://www.diyaudio.com/forums/digital- ... r-119.html

The second posted filter.

[nige2000]

https://hifiduino.wordpress.com/2015/07 ... ding-vref/

[rickmcinnis]

He works fast!

Glad I have a bunch of those OSCONs on hand from the stillboarn DDDAC project!

[nige2000]

new firmware and new filters
nos still a favourite
the umanager had me very confused :(

anyway I put 4v of lifepo4 in parallel across the vref outputs

just to see what sort of change there would be
assuming that the lifepo4 would absorb remaining noise

there was a change although not dramatic as I expected
slight increase in micro detail
firmer deeper bass
slightly improved dynamics

not sure how many hoops id jump through for this small improvement

the data sheet for the reg that powers the 1.2v says it needs at least 4.5v
dunno if it will work at 4v

best option would be to remove vref reg and run the dac of clean 3.3v =4 and -4v if the v1.2v reg will work at 4v
otherwise were stuck with the factory mod as the best alternative atm

anyway the dac sounds pretty good now

[rickmcinnis]

My plan for the SOEKRIS when I get it back with the resistors replaced (no way I could do it, I tried, just ended up with a ball of solder with a resistor deep inside) is to use the DDAC1794 shunt supply, 5 volts, at the positive power in and the BELLESONs for the +- 5 volts before the Vref.

Those damn batteries are such a pain I am thinking of initially going with supercaps after the DDDAC shunt and for the additional capacitance at Vref.

Looking at these: http://www.mouser.com/ProductDetail/Pow ... mjnr2r4%3d - on second thought I think the 1 farad ones would be better still.

Would only need three. These do not have absurdly low ESR which I think could be a problem with paralleled polymers.

Paul finds little to gain from replacing the 3.3 v reg and after his troubles I might be able to live with the "as is" reg.

Glad you are to play with audio again.

[nige2000]

replacing the 3.3v was crucial for me
that and clean +/- 5-7v must do mod
even bypassing the 5v regs did bugger all as was removing the stock electrolytics

selection of supercaps improved a bit might be worth a shot

ok ordered a couple of these
http://ie.farnell.com/bussmann-by-eaton ... dp/2148516
the supercap I put on the ram mod was 100f

[nige2000]

http://www.audiogasms.com/rocky-mountai ... mage44.jpg[/img]