Possum
500+ Head-Fier
- Joined
- Jun 22, 2001
- Posts
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Recently, after I added a digital pot (the DS1802) to my amp in place of a Panasonic that used conductive plastice, I noticed 2 situations where I would get noise, or more noise than before:
1) When I move through certain areas of my room with my headphones on, I would here very soft clicking. If I moved back and forth through a specific spot, I could repeat the clicking. I tried moving through the same spot with the headphones unplugged, and did not hear any clicking, so I'm guess there may be RF or EMI interference being transfered from the headphone cable back to the amp, then back to my headphones as this clicking noise. Could this be the cause, and could I remedy this with a few ferrite beads around the wires soldered to my headphone jack?
2) Certain sounds, if they were somewhat noisy with my analog pot, are now very very noisy with my digital pot. So noisy that you'd think something was clipping. Examples: the starting sound "Welcome to Gamespy" when you load the Gamespy online-game server browsing program. Before I could here a little bit of clipping-like noise with and without my amp. Now the noise is very pronounced. Another example, downloading the poorly ripped 320-kbps (48000 Hz sampling rate) MP3's of Blink 182's "Rock Show" song from certain sharing services. With the old pot it just sounded like the song was ripped very loudly, however, with the digital pot it just sounds like it's clipping vert severly. Could this have ANYTHING to do with my previous careless assumption that the digital pot did not depend on a specific current requirement (see thread about voltage dividers)?
EDIT: Case 2 is definitely clipping. I was able to reproduce severe clipping to the point where the digital pot resets itself. It seems to happen if there's A LOT of bass information in the song. I simulated this with any song with decent bass, then used my portable CDP's bass enhancer to add bass, and got the clipping. So the new questions is: Why is this happening with the digital pot?
1) When I move through certain areas of my room with my headphones on, I would here very soft clicking. If I moved back and forth through a specific spot, I could repeat the clicking. I tried moving through the same spot with the headphones unplugged, and did not hear any clicking, so I'm guess there may be RF or EMI interference being transfered from the headphone cable back to the amp, then back to my headphones as this clicking noise. Could this be the cause, and could I remedy this with a few ferrite beads around the wires soldered to my headphone jack?
2) Certain sounds, if they were somewhat noisy with my analog pot, are now very very noisy with my digital pot. So noisy that you'd think something was clipping. Examples: the starting sound "Welcome to Gamespy" when you load the Gamespy online-game server browsing program. Before I could here a little bit of clipping-like noise with and without my amp. Now the noise is very pronounced. Another example, downloading the poorly ripped 320-kbps (48000 Hz sampling rate) MP3's of Blink 182's "Rock Show" song from certain sharing services. With the old pot it just sounded like the song was ripped very loudly, however, with the digital pot it just sounds like it's clipping vert severly. Could this have ANYTHING to do with my previous careless assumption that the digital pot did not depend on a specific current requirement (see thread about voltage dividers)?
EDIT: Case 2 is definitely clipping. I was able to reproduce severe clipping to the point where the digital pot resets itself. It seems to happen if there's A LOT of bass information in the song. I simulated this with any song with decent bass, then used my portable CDP's bass enhancer to add bass, and got the clipping. So the new questions is: Why is this happening with the digital pot?