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DIY Stompboxes => Building your own stompbox => Topic started by: fiestared on June 22, 2020, 01:58:38 PM

Title: Musikding bluelay no effect
Post by: fiestared on June 22, 2020, 01:58:38 PM
Hi! when pedal is engaged, I get clean low volume signal, no effect at all. Had a friend who has built a lot of pedals look at it for cold joints etc, but he couldn't find anything. Changed to a brand new PT2399, same problem.

Schematic: https://www.musikding.de/docs/musikding/bluelay/BluelayV2schem.pdf

9v pin 8.53

IC 1

1 3.940
2 3.940
3 3.940
4 0
5 3.940
6 3.940
7 3.940
8 7.79

IC 2 PT2399

1. 4.56
2. 2.3
3 0
4 0
5 2.7
6 2.3
7 1.4
8 1.37
9 2.3
10 2.3
11 2.3
12 2.3
13 2.3
14 2.3
15 2.3
16 2.3

Ic3

1. 4.56
2. 0
3. 7.78

Title: Re: Musikding bluelay no effect
Post by: antonis on June 23, 2020, 05:28:29 AM
What current value is rated your power source..??
(it seems that it's loaded even with "light" loads..)

Measure its "open" voltage, i.e. with circuit disconnected..
Title: Re: Musikding bluelay no effect
Post by: fiestared on June 23, 2020, 06:43:34 AM
It is a 9v onespot 1700 ma. Had the same problem With another 9v battery. Tested with fresh battery aswell. Same problem. I am testing through a fuzzdog pumped up circuit tester.
Title: Re: Musikding bluelay no effect
Post by: anotherjim on June 23, 2020, 11:06:45 AM
All the voltages look normal - except a little on the low side. That could be your meter is under-reading? Worth checking that R7 is 33R and not something bigger. As you haven't got a serious fault, you can always temporarily solder a wire across R7 to rule that out.
If you don't have an audio probe, you can take the wire off the "Out" pcb pad and extend it to probe about for where you do have a signal. Example -  IC1 pin ought to be louder than on the "In" pad. Warning - you'll get a loud thump if you only use a wire due to the DC voltage at various places. You can insert a capacitor in series with the wire to reduce that, but if your "bench amp" isn't too loud, you might tolerate the thumps.