Hello
I've finally built my first pedal... The flanging Sounds fantastic... but Im having an issue finding out where or whats causing the double swoosh noise im hearing.
(1) Project Name - Current Lover
(2) General description of the problem - Double swoosh sound occurring when rate led goes to its brightest.
(3) Steps that you have taken to try to resolve the issue - I have done this alignment procedure below
1. Clock Trimmer (Freq Counter): Set Feedback=0%, Range=100%, Rate=0%, Switch=Filter Matrix (left position). Measure pin 1 of IC4 with frequency counter. Turn clock trim pot until frequency is 70 kHz.
*****This came out perfectly***** See First Picture
2. Bias Trimmer (O-scope): Set Feedback=0%, Range=100%, Rate=0%, Switch=Filter Matrix (left position). Place 200 Hz 1V p-p (or ~p-p V of your guitar PU output) sine wave into the input jack of pedal. Measure pin 7 or 8 of IC2 (MN3007). Adjust bias trimmer until there is no clipping. The output waveform will have an amplitude ~1.5 V p-p.
**** This step did not let me get an output over 0.5V no matter where i turned the bias to.. but the trimmer was turned clockwise until the wave stayed clean***** Picture 2 is what bias was set at...Picture 3 is what it looked like when bias trimmer was turned fully clockwise. So i dont know if something is wrong there..
3. Set T1 (O-scope): Set Feedback=100%, Range=100%, Rate=50%, Switch=Flange (right position). Turn off signal generator. Set T1 at full counter clockwise. Measure signal at output of pedal (tip wire of output jack). Signal should grow in and out with the clock (will be ~2V p-p at max). Adjust T1 trimmer until signal significantly diminished (barely visible). There is a sweet spot where the signal will go from ~1V p-p to almost nothing.
***I followed this step through with no issues****
4. Set T1 (Amp): Set Feedback=100%, Range=100%, Rate=50%, Switch=Flange (right position). Turn off signal generator. With no input, plug out put of pedal into amp. Turn feedback trimmer clockwise until a horrible high-pitched tone breaks all the windows in your house. Reduce (turn CCW) until horrible noise subsides. Don't go to far, you want to be slightly below the horrible noise to have good flanging.
***Did this as well and it worked.. trimmer was in same spot after i retried the previous step******
5. Set Vol (O-scope): Set Feedback=50%, Range=50%, Rate=50%, Switch= Filter Matrix (left position). Apply 3Khz 0.5V p-p sine wave to input jack. Measure output jack. Output signal pulses up and down. Set vol trimmer until output is minimum 0.5V p-p
*** This step i followed through as well with no issues**********
(4) List any substitutions you used for parts/values - r30 is 39k - r10 is 47k -c20 is 47pf
You can hear the swoosh when the guitar volume is off faintly... but its super loud when the volume is full and strings muted.
The flanging sounds fantastic.. just that noise thats the problem..
Im running it off a 9V boss psa-120
Any help would be appreciated..
If need be ill send a file of the sound..
Thanks!
I've finally built my first pedal... The flanging Sounds fantastic... but Im having an issue finding out where or whats causing the double swoosh noise im hearing.
(1) Project Name - Current Lover
(2) General description of the problem - Double swoosh sound occurring when rate led goes to its brightest.
(3) Steps that you have taken to try to resolve the issue - I have done this alignment procedure below
1. Clock Trimmer (Freq Counter): Set Feedback=0%, Range=100%, Rate=0%, Switch=Filter Matrix (left position). Measure pin 1 of IC4 with frequency counter. Turn clock trim pot until frequency is 70 kHz.
*****This came out perfectly***** See First Picture
2. Bias Trimmer (O-scope): Set Feedback=0%, Range=100%, Rate=0%, Switch=Filter Matrix (left position). Place 200 Hz 1V p-p (or ~p-p V of your guitar PU output) sine wave into the input jack of pedal. Measure pin 7 or 8 of IC2 (MN3007). Adjust bias trimmer until there is no clipping. The output waveform will have an amplitude ~1.5 V p-p.
**** This step did not let me get an output over 0.5V no matter where i turned the bias to.. but the trimmer was turned clockwise until the wave stayed clean***** Picture 2 is what bias was set at...Picture 3 is what it looked like when bias trimmer was turned fully clockwise. So i dont know if something is wrong there..
3. Set T1 (O-scope): Set Feedback=100%, Range=100%, Rate=50%, Switch=Flange (right position). Turn off signal generator. Set T1 at full counter clockwise. Measure signal at output of pedal (tip wire of output jack). Signal should grow in and out with the clock (will be ~2V p-p at max). Adjust T1 trimmer until signal significantly diminished (barely visible). There is a sweet spot where the signal will go from ~1V p-p to almost nothing.
***I followed this step through with no issues****
4. Set T1 (Amp): Set Feedback=100%, Range=100%, Rate=50%, Switch=Flange (right position). Turn off signal generator. With no input, plug out put of pedal into amp. Turn feedback trimmer clockwise until a horrible high-pitched tone breaks all the windows in your house. Reduce (turn CCW) until horrible noise subsides. Don't go to far, you want to be slightly below the horrible noise to have good flanging.
***Did this as well and it worked.. trimmer was in same spot after i retried the previous step******
5. Set Vol (O-scope): Set Feedback=50%, Range=50%, Rate=50%, Switch= Filter Matrix (left position). Apply 3Khz 0.5V p-p sine wave to input jack. Measure output jack. Output signal pulses up and down. Set vol trimmer until output is minimum 0.5V p-p
*** This step i followed through as well with no issues**********
(4) List any substitutions you used for parts/values - r30 is 39k - r10 is 47k -c20 is 47pf
You can hear the swoosh when the guitar volume is off faintly... but its super loud when the volume is full and strings muted.
The flanging sounds fantastic.. just that noise thats the problem..
Im running it off a 9V boss psa-120
Any help would be appreciated..
If need be ill send a file of the sound..
Thanks!