John Hollis Flanger Debugging

Started by abakuzam, December 19, 2018, 12:53:11 PM

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abakuzam

Hello folks, i'm having troubles to get it work and i'm a little bit confused about it. I hope i can get some feedback to solve my problem and learn more about the pedals along the journey :icon_redface:


Layout : http://effectslayouts.blogspot.com/2016/03/john-hollis-ultra-flanger.html

Schematic : http://www.hollis.co.uk/john/ultraflanger3.jpg


Substutions:

2 regular green LED , i measured 3,84v drop, i used 1N5817 instead of 1N4001

Here is what i did:

- i checked components and soldering ( not the best one but, i did contiunity test for all )
- Tried to use trimpots to get the 4.9v but they didn't do any effect, im confused about it
- Checked the voltages and frequencies, my lfo seems to be working
- Tried TL022 for LFO, and changed the MN3007
- i have a 1 volt voltage drop after the supply, i checked the 100R resistor if i put in there 1K or something, it's correct. I pulled off U1 and U5 and i got 8,96v. But couldn't find any shorts etc to drop the voltage that much.
-Current consumption is 10mA while all pots CCW, 16mA when CW, odd/even switch doesn't change anything.
- I measured 50kHz - 1MHz at shown pins at the schematic, but somehow i got 2.1MHz while playing with the sweep and manual knobs, then sound gets distoted with no modulation effect ( i was able to hear lfo pulsing before it )
- This is how it sounds : https://ufile.io/ak97r

Here is my voltages ( sorry for not able to write all them in here )