Originally Posted by evraamsdonk
Thanks for the advice. The reason I assume it's a linear pot is because it's labeled "B100K", and from the info I found the 'B' means linear. I also found that logarithmic pots (or audio pots) are usually used for audio amplifiers, like you said. (Strange that they would use a linear one for this Zero dac/amp then.)
Should I get a audio pot with the same resistance value of 100K?
I would do a couple more checks first.
Do you have any measurement equipment? You can do this with an SPL meter, or a resistance meter (digital multimeter is perfect). IMO *EVERYONE* interested in the audio hobby should own both. Even non-DIYers should own them, The SPL meter is nice for safety, and the DMM has so many uses.
If you have a resistance meter figuring this out for sure will be so easy! Take the headphone amp board out of the chassis. Set the volume knob to the exact middle of its travel. Measure the resistance from one end of the pot to the middle, and the other way around. With a linear pot the resistance will be roughly half so 50K. With an audio pot, I'd expect something around 250-1Kohm or ~97Kohms depending which side you measure from.
With an SPL meter I would do the following:
Obtain a 1Khz test-tone or white/pink noise and play it - you can download one or just make one in all sorts of computer software. Set the volume to minimum and hook up the DT880. Turn the volume knob up roughly 5min on a clock face. note the SPL. turn it up again, note etc. If the pot is an audio taper one the SPL with increase equally with each equal bump of the knob. If its linear the SPL will increase very rapidly for a given spin of the pot at first, and then not increase so rapidly on the louder end of the pot.
If you have a linear pot, get that out of there. Linear taper pots are often used in less expensive gear because less expensive samples work better. Every time you throw another step into a process there is another point to screw it up.... being simpler to make linear pots DO work better in some ways.
If you do already have an audio taper pot, life is rough :) Im betting you have a linear pot, but please double check me before you go out and get a new one.
Whether to get 100K ohms, or something else if you need to change it... This is kind of tricky. The absolute sure-fire answer is to get 100K, same as before.