Author Topic: Fraudhacker - LFO tick noise (wth did I do)  (Read 1963 times)

jessenator

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Fraudhacker - LFO tick noise (wth did I do)
« on: March 07, 2023, 08:08:07 PM »


Alright, let's see what I did RoNg this time. Just a few things to get out of the way:

I routed all wire off to the left, to avoid the LFO/clock as much as possible.

The reg looks backwards, but the part I have (ST L78L05CZ) has reversed pins.

The 33uF caps (C26, C27, C35) are tantalum (supposedly bipolar??), but are oriented off lead length (no pole indicators) just in case.

Those friggin Xvive labels are terrible to see in any light, but is a 3007. It and the 3101 were both working when I pulled them from my Pork Barrel.


During calibration I get next to no signal from TP2 (unless I really crank up the gain on my desktop amp), and even when I adjust it to be the clearest, there's still LFO tick.

The 22k trimpots are 20k

When I try to calibrate the clock with my Fluke, I'm barely getting 3 kHz (at least I think I'm using it correctly).

Actually now I'm listening again, it's not self-oscillating, though I'm sure how that would sound on this particular circuit to tell, so at any rate, T1 for feedback doesn't really have a dramatic effect


Apologies if I've forgotten something basic  :-\

jessenator

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #1 on: March 09, 2023, 10:27:45 PM »
alright, I've still got intense ticking, but here's a video :P



Sorry it's over 5 minutes. I re-flowed everything, and can't figure out what's going on. Any ideas would be welcome :)  Thanks.

blackhatboojum

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #2 on: March 10, 2023, 10:03:08 AM »
Are you sure about your voltage regulator?  I used an ST Micro 78L05ACZ on both of my fraudhacker builds and it's oriented just like the silkscreen on the pcb.
« Last Edit: March 10, 2023, 10:13:40 AM by blackhatboojum »
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jessenator

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #3 on: March 10, 2023, 10:34:48 AM »
78L05ACZ

Yeah, I need to get rid of the remaining few of whatever I have, because it's an extra variable with builds like this that need a reg— it's an L78L05ACZ https://www.taydaelectronics.com/datasheets/A-176.pdf which has the I/O pins reversed…at least on the diagram.

I am half tempted to clip it and splice in a standard one where there's no mystery. In a wonderful happenstance, a number of non-L specimens showed up in a big batch of NPNs while I was measuring them all.

Govmnt_Lacky

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #4 on: March 10, 2023, 10:55:56 AM »
The 33uF caps (C26, C27, C35) are tantalum (supposedly bipolar??), but are oriented off lead length (no pole indicators) just in case.

Fairly certain that Tant caps cannot be bipolar. Unless you use 2 in series with the same polarities connected like C27/C27).

As long as you put the longer lead into the (+) pad then you should be ok

blackhatboojum

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #5 on: March 10, 2023, 11:48:28 AM »
78L05ACZ

Yeah, I need to get rid of the remaining few of whatever I have, because it's an extra variable with builds like this that need a reg— it's an L78L05ACZ https://www.taydaelectronics.com/datasheets/A-176.pdf which has the I/O pins reversed…at least on the diagram.

I am half tempted to clip it and splice in a standard one where there's no mystery. In a wonderful happenstance, a number of non-L specimens showed up in a big batch of NPNs while I was measuring them all.

Yep, That's the exact voltage regulator I've used on all of my boss and ibanez flanger builds.  Same exact part number and I purchased them from Tayda.  You definitely have yours in the wrong direction. 

EDIT:  The pin connection on that datasheet for the TO-92 package is BOTTOM view.  I think that's why your getting confused.
« Last Edit: March 10, 2023, 12:19:19 PM by blackhatboojum »
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jessenator

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #6 on: March 10, 2023, 12:16:58 PM »
Yep, That's the exact voltage regulator I've used on all of my boss and ibanez flanger builds.  Same exact part number and I purchased them from Tayda.  You definitely have yours in the wrong direction.




well I flipped it just to see, and while not nearly as strong, the click remains… I feel like I've seriously borked something. Adjusting some of the pots also now stops modulation entirely…

Edit: also, I can now get a signal from TP2, so I've got that going for me. Also, by "cleanest sounding output": I'm hearing a heavily pitch-modulated sawtooth(?) sort of waveform (like on an analog synth), so am I looking for unmodulated? just a clean basic waveform tone?
« Last Edit: March 10, 2023, 12:24:56 PM by jessenator »

blackhatboojum

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #7 on: March 10, 2023, 12:41:04 PM »
Now that you have the voltage regulator sorted, Here's how I set up my fraudhackers.  For the clock frequency, set your manual and depth knobs to minimum.  Probe TP1 with your dmm on it's frequency setting and adjust your clock trimmer to 40kHz.

For bias, set your depth and res knobs to minimum.  Input your sine wave.  Now, audio probe TP2 or if you want to follow the official boss service notes, probe pin 1 of Q3, and adjust your bias trim to the cleanest sound.

For the resonance set manual and depth knobs to minimum.  Set your res knob to max.  Hook up the output of your pedal to an amp, and short the input jack tip to the sleeve.  Now adjust T1 to just below self oscillation.

If you still have weird stuff going on after this then we'll have to do some more troubleshooting but your main initial issue has been corrected.
« Last Edit: March 11, 2023, 01:04:10 AM by blackhatboojum »
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jimilee

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #8 on: March 10, 2023, 01:06:51 PM »
The 33uF caps (C26, C27, C35) are tantalum (supposedly bipolar??), but are oriented off lead length (no pole indicators) just in case.

Fairly certain that Tant caps cannot be bipolar. Unless you use 2 in series with the same polarities connected like C27/C27).

As long as you put the longer lead into the (+) pad then you should be ok
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blackhatboojum

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #9 on: March 10, 2023, 01:13:29 PM »
I should also mention that there's a possibility your regulator might need to be replaced with a new one.  I know they're sensitive to reverse polarity but, I'm not sure about having the input and output reversed.
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jessenator

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #10 on: March 10, 2023, 01:35:06 PM »
Now that you have the voltage regulator sorted, Here's how I set up my fraudhackers.  For the clock frequency, set your manual and depth knobs to minimum.  Probe TP1 with your dmm on it's frequency setting and adjust your clock trimmer to 40kHz.

For bias, set your depth and res knobs to minimum.  Input your sine wave.  Now, audio probe TP2 or if you want to follow the official boss service notes, probe pin 1 of Q3, and adjust your clock trim to the cleanest sound.

For the resonance set manual and depth knobs to minimum.  Set your res knob to max.  Hook up the output of your pedal to an amp, and short the input jack tip to the sleeve.  Now adjust T1 to just below self oscillation.

If you still have weird stuff going on after this then we'll have to do some more troubleshooting but your main initial issue has been corrected.

I should also mention that there's a possibility your regulator might need to be replaced with a new one.  I know they're sensitive to reverse polarity but, I'm not sure about having the input and output reversed.

Thank you! I'll give this a try later today. I think I've been totally mixed up on this whole thing; so I've got a humble pie to eat.

jessenator

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #11 on: March 10, 2023, 01:43:15 PM »
If I hadn't already done a design for this enclosure, I would've called (my build, anyway) the FraughtHacker    : P

blackhatboojum

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #12 on: March 10, 2023, 02:07:55 PM »
Now that you have the voltage regulator sorted, Here's how I set up my fraudhackers.  For the clock frequency, set your manual and depth knobs to minimum.  Probe TP1 with your dmm on it's frequency setting and adjust your clock trimmer to 40kHz.

For bias, set your depth and res knobs to minimum.  Input your sine wave.  Now, audio probe TP2 or if you want to follow the official boss service notes, probe pin 1 of Q3, and adjust your clock trim to the cleanest sound.

For the resonance set manual and depth knobs to minimum.  Set your res knob to max.  Hook up the output of your pedal to an amp, and short the input jack tip to the sleeve.  Now adjust T1 to just below self oscillation.

If you still have weird stuff going on after this then we'll have to do some more troubleshooting but your main initial issue has been corrected.

I should also mention that there's a possibility your regulator might need to be replaced with a new one.  I know they're sensitive to reverse polarity but, I'm not sure about having the input and output reversed.

Thank you! I'll give this a try later today. I think I've been totally mixed up on this whole thing; so I've got a humble pie to eat.

You're welcome.  We've all been there.  I've had plenty of "Doh!" moments with some of my builds. 
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Bio77

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #13 on: March 10, 2023, 03:05:26 PM »
Build docs talk about LFO/clock ticking with 3001/3007 and no regulator.  I think the regulator is a good candidate for what is wrong.  Do you have a 3207 and 3201 you could try?  I don't see much advantage for having a 3007 in this one. 

jessenator

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Re: Fraudhacker - LFO tick noise (wth did I do)
« Reply #14 on: March 10, 2023, 05:33:51 PM »
Build docs talk about LFO/clock ticking with 3001/3007 and no regulator.  I think the regulator is a good candidate for what is wrong.  Do you have a 3207 and 3201 you could try?  I don't see much advantage for having a 3007 in this one.

Sadly no. I cannibalized those from my Pork Barrel, since I couldn't find any other BBDs for sale at the time I was building, but looks like they are back.