Cool. Thank you.
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#1291
Requests / Re: Is Current Lover (2015) Calibration Possible with O-Scope or Frequency Counter?
March 12, 2018, 08:24:06 PM #1292
Requests / Re: Is Current Lover (2015) Calibration Possible with O-Scope or Frequency Counter?
March 12, 2018, 07:13:04 PM
Hi All,
I put everyone's advice into practice this weekend. The pedal sounds much better after this calibration compared to my initial "by ear" attempt. I typed up a protocol below in case anyone would find it useful. I used a cheap frequency counter I got on Amazon (Neoteck Multimeter, ~$22) and an old tektronix scope I bought on craigslist. I used my smartphone as the signal generator. There is an app called Function Generator Pro that I bought for a few dollars. I soldered a few leads with clips on to an old headphone jack.
I did have a problem: there isn't enough range on the clock and bias trimmer to trim them properly. I ended up setting the clock trimmer to ~42kHz (the lowest freq possible, trimmer at max position) and the bias trimmer still shows a small amount of clipping even at max position. If any one knows a way to modify the pedal to get more range out of the clock and bias trimmers, please advise.
Procedure:
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 freq ~35 kHz.
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.
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.
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.
5. Set Vol (O-scope): Set Feedback=50%, Range=50%, Rate=50%, Switch= Filter Matrix (left position). Apply 1V p-p sine wave to input jack. Measure output jack. Set vol trimmer until output = 1V p-p.
I put everyone's advice into practice this weekend. The pedal sounds much better after this calibration compared to my initial "by ear" attempt. I typed up a protocol below in case anyone would find it useful. I used a cheap frequency counter I got on Amazon (Neoteck Multimeter, ~$22) and an old tektronix scope I bought on craigslist. I used my smartphone as the signal generator. There is an app called Function Generator Pro that I bought for a few dollars. I soldered a few leads with clips on to an old headphone jack.
I did have a problem: there isn't enough range on the clock and bias trimmer to trim them properly. I ended up setting the clock trimmer to ~42kHz (the lowest freq possible, trimmer at max position) and the bias trimmer still shows a small amount of clipping even at max position. If any one knows a way to modify the pedal to get more range out of the clock and bias trimmers, please advise.
Procedure:
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 freq ~35 kHz.
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.
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.
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.
5. Set Vol (O-scope): Set Feedback=50%, Range=50%, Rate=50%, Switch= Filter Matrix (left position). Apply 1V p-p sine wave to input jack. Measure output jack. Set vol trimmer until output = 1V p-p.
#1293
Requests / Re: Is Current Lover (2015) Calibration Possible with O-Scope or Frequency Counter?
March 05, 2018, 11:42:27 PM
I'm not sure that's what it means. Pin 7 and 8 are outputs on the MN3007 (Thank you, Scruffie). Pin 3 is the input.
I'm reading this to mean: I place the 200 Hz input signal into the pedal input jack, measure the output at pin 7 or 8, adjust the bias trimmer until I see clipping, back off from that point until the clipping is gone.
So, I would assume the input amplitude should be in the range of a guitar pick up (maybe ~1V p-p). Or maybe it doesn't matter.
Also, I just noticed on the Mistress Mystery page there is a link to the original EH calibration doc:
http://www.metzgerralf.de/elekt/stomp/mistress/images/nsc/dem_alignment_post_79.jpg
I'm reading this to mean: I place the 200 Hz input signal into the pedal input jack, measure the output at pin 7 or 8, adjust the bias trimmer until I see clipping, back off from that point until the clipping is gone.
So, I would assume the input amplitude should be in the range of a guitar pick up (maybe ~1V p-p). Or maybe it doesn't matter.
Also, I just noticed on the Mistress Mystery page there is a link to the original EH calibration doc:
http://www.metzgerralf.de/elekt/stomp/mistress/images/nsc/dem_alignment_post_79.jpg
#1294
Requests / Re: Is Current Lover (2015) Calibration Possible with O-Scope or Frequency Counter?
March 04, 2018, 09:37:34 PM
Cool. Thanks so much for the replies.
For the Bias adjustment, the instructions say:
"Connect a 200 Hz sine wave to the input and adjust the BIAS trim for maximum input signal amplitude without clipping at SAD1024 pin 6 or 12 (TP2*). The input amplitude should now be greater than 1 V p-p."
What should be the amplitude of the 200 Hz input signal from the signal generator?
For the Bias adjustment, the instructions say:
"Connect a 200 Hz sine wave to the input and adjust the BIAS trim for maximum input signal amplitude without clipping at SAD1024 pin 6 or 12 (TP2*). The input amplitude should now be greater than 1 V p-p."
What should be the amplitude of the 200 Hz input signal from the signal generator?
#1295
Requests / Is Current Lover (2015) Calibration Possible with O-Scope or Frequency Counter?
March 04, 2018, 05:46:38 AM
Hi All,
I was hoping somebody with knowledge would be willing to lay out a method to calibrate the Current Lover (2015) with a frequency counter (if possible) or an o-scope. I'm having some trouble with calibrating by ear. I've gotten it to work, but I was looking for a more systematic way to get it really nice.
I've looked at other MB posts and found the following reference: Mistress Mystery page http://www.metzgerralf.de/elekt/stomp/mistress/align.shtml. I'd guess the Current Lover is a Delux Reissue V4 or V5, but I'm not exactly sure.
I would really appreciate any help connecting this method to the Current Lover or developing a new method for calibration.
I was hoping somebody with knowledge would be willing to lay out a method to calibrate the Current Lover (2015) with a frequency counter (if possible) or an o-scope. I'm having some trouble with calibrating by ear. I've gotten it to work, but I was looking for a more systematic way to get it really nice.
I've looked at other MB posts and found the following reference: Mistress Mystery page http://www.metzgerralf.de/elekt/stomp/mistress/align.shtml. I'd guess the Current Lover is a Delux Reissue V4 or V5, but I'm not exactly sure.
I would really appreciate any help connecting this method to the Current Lover or developing a new method for calibration.