savage Posted June 10, 2004 Report Share Posted June 10, 2004 Lo all,I'm baffled a little bit - however, I think I have found a rather uhm.. easy solution. I've read on the forum about all the problems with the "standard" digital volume control using the DS1669 IC. It semi makes sense, and surely does create a couple of "unique" problems.What I was wondering now... Would it be possible to use the same circuit (almost) as shown in the Digital Volume Meter, in conjunction with Philip's TDA1524A to do the audio controls? The chip from Philips also gives allot more flexibility, as it has left/right controls, treble, bass, balance, etc... My idea now thus, is to use the TDA1524A as a simple audio controller, and use the DS1669 as the "controls" linking up to the TDA1524A...Would this be possible, and move away (if it can be put that way) from the problems discussed on this list regarding the Digital Volume Control (DS1669)???ThanksChris.Datasheets: TDA1524A http://www.semiconductors.philips.com/pip/TDA1524A_V4.htmlDS1669: http://pdfserv.maxim-ic.com/en/ds/DS1669.pdf Quote Link to comment Share on other sites More sharing options...
gsmaster Posted June 10, 2004 Report Share Posted June 10, 2004 Are you in my brain man? About a year ago I discovered a TDA1524 in a dismantled car radio, when I looked the datasheet I liked It and I wanted to use it. I desoldered the ic and tested it in a breadboard with analog potensiometers (worked fine). The same time I ordered some digital potensimeters from maxim, but I never tested it... Quote Link to comment Share on other sites More sharing options...
MP Posted June 10, 2004 Report Share Posted June 10, 2004 savage, what problems are you refering to? I can only find two posts regarding the DS1669 and one is saying he cannot get it in his country. Are you only refering to the one post?MP Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 11, 2004 Report Share Posted June 11, 2004 Savage,You could use DS1669 linear-stepped digital pot chips with the TDA1524A controls chip since the latter converts the linear control to a logarithmic response. But the TDA1524A has a 15 percent dead-band at its low volume end and a 20 percent dead-band at its high-volume end, requiring resistors to be connected in series with both ends of the digital pots to eliminate this.The National LM1036 controls chip is newer, also converts linear to log and does not have dead-bands. Its datasheet is here:http://www.national.com/ds.cgi/LM/LM1036.pdfThe DS1669 has another problem:Can you live with the "sometimes" memory of the DS1669, where it only remembers its position if a subtantial change was made?It seems that they arranged it so that its 50,000 burns-limit does not happen too soon. They even say that when that burns-limit does occur, then it will still power-up with its last-burned position.What are the chances of that burns-limit happening to both stereo separate pots at the same time? Pretty slim odds. Think about the consequences, "What happened to the balance?"!!I know, you could leave it powered all the time.Maxim have a logarithmic stereo volume/balance digital pots chip that also has pushbutton controls, but it does not have a memory. It is the DS1802, and its datasheet is here:http://pdfserv.maxim-ic.com/en/ds/DS1802.pdfYou could also leave it powered all the time. Quote Link to comment Share on other sites More sharing options...
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