till
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I am thinking of using a digital potentiometer in my next amp because the noise, channel imbalance and/or sheer size of most analog pots is getting on my nerves. Most digital pots require a certain voltage to operate and thus need their own electrical system, negating any space saved by ditching an analog pot - well, thinking of this, they allow for a more spread-out design instead of the cubic form factor most quality analog pots have. The only variable and high-voltage model I found is the AD7376 (from +-5V to +-15V), but alas, it is available as a single-channel version only.
These are the ICs I can get over here without more-than-usual difficulty, with some of their characteristics:
An alternative might be the TDA1524. It needs some extra components such as an analog pot, but it accepts a wide range of voltage and is very cheap. It can also modulate bass, treble and balance.
Here is a link to the datasheet, which is quite hard to find:
http://www.produktinfo.conrad.com/da...-tda_1524a.pdf
Here is a circuit diagram for using it as a volume control (sorry, in German only):
http://mitglied.lycos.de/hobbyelec/a...regelstufe.zip
However, the TDA1524 seems to be quite old-fashioned. Its need for an analog pot adds to space requirements, defeating the purpose of saving space with a digital pot. OTOH, you can use a nice knob instead of pushbuttons, without an analog pot´s scratchy noise
I did not find much information about digital pots. Any recommendations? On Headwize, Apheared wrote that the DS1802 works well for him, but in another posting someone else reported about clipping at high volumes.
Please tell me what you think and also if I got something wrong or missed some important points (which I´m sure of
). Also, I´m just getting started with this and electronics in general and do not get the whole picture, i.e. how hard it might be to provide a steady voltage that most of the aforementioned pots require. Using a microcontroller is beyond my grasp at this time, but I might give it a try later.
Or would I be better off skipping this idea and using an expensive (and big!) analog Alps pot?
EDIT: typo and CAT523 voltage.
EDIT 2: I just found Mark Hennessy's homepage, which has a section that discusses several digital potentiometers:
http://www.mhennessy.f9.co.uk/preamp...e_research.htm
These are the ICs I can get over here without more-than-usual difficulty, with some of their characteristics:
- DS1666: +-5V / +5V, single, log, 10k/50k/100k
- DS1802: +-5V / +3 to +5V, dual, log, 45k, pushbutton operation
- DS1267: +-5V / +5V, dual, lin, 10k/50k/100k
- DS1867: non-volatile version of DS1267
- DS1808: +-12V, dual, log, 45k
- AD7376: +-5V to +-15V, single, 10k/50k/100k/1M
- CAT523: +2,7 to +5,5V, dual, 28k, non-volatile
- TDA1524: +3 to +18V, dual, not a true digital potentiometer?
An alternative might be the TDA1524. It needs some extra components such as an analog pot, but it accepts a wide range of voltage and is very cheap. It can also modulate bass, treble and balance.
Here is a link to the datasheet, which is quite hard to find:
http://www.produktinfo.conrad.com/da...-tda_1524a.pdf
Here is a circuit diagram for using it as a volume control (sorry, in German only):
http://mitglied.lycos.de/hobbyelec/a...regelstufe.zip
However, the TDA1524 seems to be quite old-fashioned. Its need for an analog pot adds to space requirements, defeating the purpose of saving space with a digital pot. OTOH, you can use a nice knob instead of pushbuttons, without an analog pot´s scratchy noise
I did not find much information about digital pots. Any recommendations? On Headwize, Apheared wrote that the DS1802 works well for him, but in another posting someone else reported about clipping at high volumes.
Please tell me what you think and also if I got something wrong or missed some important points (which I´m sure of
Or would I be better off skipping this idea and using an expensive (and big!) analog Alps pot?
EDIT: typo and CAT523 voltage.
EDIT 2: I just found Mark Hennessy's homepage, which has a section that discusses several digital potentiometers:
http://www.mhennessy.f9.co.uk/preamp...e_research.htm