Discrete DA converter?

[spreemusik]

Cleaning up the workshop I found a whole bag of r2r ladders, 1.2meg total in 10 pin SIL package. Must be about 250 of them, probably more. So perhaps I should build a DAC? 8bit isn't much these days, but perhaps I can find a few that match well.
Or a digital sidechain? Any other uses?

 

[volker]

You could do a little digital synth / noisemaker using a µC or something similar.
To get the right lofi feel an 8 bit DAC sounds just about right  .


Volker

 

[clintrubber]

MIDI-2-CV ?

 

[spreemusik]

Midi 2 cv is a great idea. I have a couple of simply synth schematics floating around too.

 

[clintrubber]

Hi,

Please keep us posted !

As it happens, I’m currently having a look at analog filters & MIDI-control. A common problem that’s brought up in the reviews of various commercial types is the steps people perceive in the filter-freq. Sounds like the limited resolution of MIDI-control at work here (probably these filters use just 128 values ?).
Weren’t there other dedicated MIDI-controllers with way finer resolution ?

Bye,

  Peter

 

[JohnRoberts]

I recently looked at r-2r ladders for a design project and found them quickly becoming un-competitive with digital pots for 8-9 bit range, and from there cost effective solutions jump up to 16b audio codecs...  It looks like R-2r ladders are going obsolete.  FWIW

JR

 

[spreemusik]

You can gang a number of midi controllers to MSB LSB pairs, giving you 14 bits.

With most uCs today having at least 10bit DACs on boards, I'm sure there is no longer much use for r2r ladders. But seeing that I have more than enough of them, I might as well put them to use. Perhaps a nice little drum synth with midi input and digital control? Oh, but to find the time...

 

[spreemusik]

Oh, and if anyone wants to play around with ladders, I can part with a couple.

 

[clintrubber]

Oh, and if anyone wants to play around with ladders, I can part with a couple.

Would these qualify for decent audio-passing duties ? Would be fun to make a few dual single ended 6 dB step attenuators,
I'll cover stamps etc.
What's the resistor-value R ?

Bye,

  Peter

 

[spreemusik]

I suppose the value will be a bit high for audio. They're 1.2meg total, 100k difference across the legs.
But I'll gladly put a few (10? 20?) in an envelope and send them over.

 

[clintrubber]

Hi, thanks, PM'd you.

 

[clintrubber]

It looks like R-2r ladders are going obsolete.  FWIW

There's this weird thing with DIY that sometimes something being an obsolete way of doing things can make that path actually more attractive...
let's be glad this doesn't turn op too often.    


(I recall having seen a hollow-state MIDI-interface  8) , but not sure if it was for real or not)
You recently had a word/name for it, I think it's good that things like that exist.