Digital Volume Control

[koolscooby]

Originally posted by soundNERD
Well, i donno 2 much about microcontrollers. 2 be honest, ive never used one before. So, whatever is cheap and can be eaily bought. (as always i like free samples).

-Mike

Well i'm not aware anywhere that you can get PIC's or AVR's for samples, but PIC's are rather cheap... the PIC16F series only requires something like 4 parts external to create a programmer... but if you buy the debugger kit from them ,its agood 200 bucks... well just my recommendation is a pic16f...

[Hybrid fourdoor]

Originally posted by mhennessy


An exception to this is the Dallas DS1802, which can be controlled by pushbuttons. I considered it for use in my preamp, you can read what I though here: http://www.mhennessy.f9.co.uk/preamp...e_research.htm

Cheers,

Mark

I saw you had lots of problems with clicking during volume change with the digital pots. there a paper over at Maxim that might be of interest to you. It concerns the DS1802, but has an interesting writeup in the beginning about ways to eliminate the clicks in digital pots.

Application note over at Maxim-IC

[jackinnj]

Originally posted by jackinnj
"Parallel in Serial Out" shift register (74HC595) --

should have said '165, not '595

[mhennessy]

Originally posted by jackinnj
No you don't need a microcontroller -- but it is easier with one -- the LM1971,2,3 are synchronous devices so you either toggle the clock line yourself or use a slow-moving 555, an 8-bit "counter" and a "Parallel in Serial Out" shift register (74HC595) -- bring the Load line "LOW", set the address of the LM1972 (0,1,2), by transmitting 8 bits, then transmit the dB/mute setting (second 8-bits), bring the Load Line "High". Parts to do this are about $1.00.

If using a pushbutton for up down, consider how many milliseconds you want the '555 to run for the full gamut.

"Software" in solder -- the old fashioned way -- still works as Steve Ciarcia is wont to say.

While you're right, would you seriously attempt it these days? I remember playing these games 10 years ago, before the flash PICs were around. I really wouldn't go back, and wouldn't advise anyone to attempt it either. This sort of project is the ideal motivation to learn PIC or AVR. Once you've crossed that hurdle, just think about the possibilities afterwards

Originally posted by koolscooby
And let me add, that your pre-amp is really hardcore-style-awesome ... i plan to build something similar to it when i have abilities even close to yours

Well, thank you

If it's any encouragement, I didn't know how to programme PICs when I started - see above...

Originally posted by koolscooby
Well i'm not aware anywhere that you can get PIC's or AVR's for samples, but PIC's are rather cheap... the PIC16F series only requires something like 4 parts external to create a programmer... but if you buy the debugger kit from them ,its agood 200 bucks... well just my recommendation is a pic16f...

You can get PIC samples from the Microchip website. Very handy

Originally posted by Hybrid fourdoor
I saw you had lots of problems with clicking during volume change with the digital pots. there a paper over at Maxim that might be of interest to you.

Thanks for this - I'll be reading it later...

Interestingly, I've just noticed that there's a DS1802 in my portable Sony MD recorder - it's used to give volume control to the headphone output. And, it sounds pretty good to me...

Cheers,

Mark

[deandob]

SoundNerd, you have mail.

Regards,
Dean

[jackinnj]

Originally posted by mhennessy

While you're right, would you seriously attempt it these days? I remember playing these games 10 years ago, before the flash PICs were around. I really wouldn't go back, and wouldn't advise anyone to attempt it either. This sort of project is the ideal motivation to learn PIC or AVR. Once you've crossed that hurdle, just think about the possibilities afterwards

I use PicBasic Pro and an MELabs serial programmer -- but anyone who uses PIC's probably has '595's and '165's hanging around.

That's OK, I had to explain Ohm's law to someone who was MCSE certified the other day.

[elektroman]

You can control volume with a DS 1802 ic. It's a digital volume control with 50k resistance.I think it can be controlled with 2 bottoms.Or it doesn't works you can built a simple circuit with an 74193 counter,an 4016 analog switch and some resistance.
I have this circuit,if I find it i share here.

[dbbaker2007]

Phew this is an old thread!

I was wondering if anyone still has deanbobs schematic and code for the LM1972!