Swarangini Digital is an electronic tanpura machine that delivers high quality original tanpura sounds. It has been introduced to the market in 2008. For more info about this very handy and popular machine visit the Sound Labs website. The machine is excellent for tuning and accompaniment. But, since this is a digital machine, it has a big disadvantage: the main volume is not anymore adjusted continuously but in steps. And, unfortunately, these steps are rather big, especially in the lower volume regions. Also the lowest sound ever is still much too loud in many occasions such as practice at home.
The most simple and very adequate solution is to create yourself an analog volume fine tuning knob by putting a potmeter in series with the loudspeaker. The only consideration which has to be taken into account is that this part of the circuit works under a slightly higher current level since it is the main amplifiers output. So, best is to choose a wire-wounded (high power) potmeter. A value of 50 Ohms, 4 Watts works great.
Open the box by removing the 4 screws and cutting the warranty seal sticker. Drill a 10mm hole through the side and remove the excess plastic on the inside to make room for the potmeter. Fix the potmeter and loosen the black wire which is leading to one of the solder lugs of the speaker. Solder this wire to the middle lug of the potmeter. Take another piece of insulated copperwire and solder it between the adjacent potmeter lug and the speaker lug on which the black wire was attached before. Close the box and mount a nice knob. Thats all for your custom volume finetuning knob…