Soekris Dam Dac

[randytsuch]

Looks like he added 4 transistors on the output end, wonder what for.

[randytsuch]

What filter are you guys using?

I figured out today that I "broke" my dac by trying to use old filters with 0.99 firmware.

http://moredamfilters.info/filters

I was looking at the v099 party pak.

Randy

[nige2000]

Looks like he added 4 transistors on the output end, wonder what for.

think there's 6 more?
maybe new mute system?
transistor on outputs?

[nige2000]

What filter are you guys using?

I figured out today that I "broke" my dac by trying to use old filters with 0.99 firmware.

http://moredamfilters.info/filters

I was looking at the v099 party pak.

Randy

im using pauls newnos everything else i tried has less resolution and frequency limitations
newnos is most lifelike/realistic for me

any rough edges are ironed out improving the dac

[randytsuch]

See pics below, courtesy of Nigel


I disconnected my negative supply, removed the opamps that generate +/-4V, removed the caps on the output signal, removed the +/-5 volt regulators and the caps on those lines.

So now power is from two lifepo4 batteries for the shift registers, and one walwart for +A, and one walwart for 3.3V iso.

And it sounds really good now, I think it's now better than my other DAC, but I need to listen more.

Randy

[nige2000]

[nige2000]

what voltage have you got on vref and going to the 1.2v reg?

under 4v for me wouldnt power the 1.2v sm reg so wouldnt function

once you bypass the 1.2 sm reg and 3.3 ldo you dont need power at main input any more

[randytsuch]

what voltage have you got on vref and going to the 1.2v reg?

under 4v for me wouldnt power the 1.2v sm reg so wouldnt function

once you bypass the 1.2 sm reg and 3.3 ldo you dont need power at main input any more

I think vref is the voltage to the shift registers?

I have one cell on each, putting out around 3.3 volts. I'm charging them to 3.4V right now, but they quickly go back to 3.3v.
I may adjust my charging voltage down to 3.3v.

The 1.2v switcher is powered by A+, same as the 3.3 linear reg.
I haven't touched that yet, that's next on my list of things to do.
I'm going to put in a lifepo4 for 3.3V, and remove the linear reg on the board.
I'll also add a 1.2v ldo reg, running from a lifepo4, and remove the 1.2v switcher.

Right now I'm feeding in about +10VDC from a walwart, and that is powering the 1.2V switcher and the 3.3V linear reg
The two lifepo4 cells power the shift registers.
That appears to be all you need, as it is working fine like that.

[nige2000]

more improvement
speed/agility
decay/echo
resolution

maybe the 100nf caps weren't doin any harm but i took em off anyway
i do have film caps to go on, i just thought i should listen before i do that
now struggling to find a reason to put them on

[jkeny]

Nige,
What did you change apart from removing the logic shifter bypass caps (which I don't think it is a good idea)?