Zombie chorus with anti tick mod 1590b layout?..

[Perrow]

@pelle:  any news?...

Yes, our new windows are nicely installed, about half of the stuff we shuffled out of the way is back to where it should be and we've spent most of the day at IKEA planning our new kitchen

Hopefully get some cave time this week, but can't promise anything

[deadastronaut]

at least you have windows now though...

[Perrow]

Yeah, was quite dark before

I stole a few minutes to debug last night and can now say with certainty that this circuit works better with the input cap installed. No chorus yet though.

[deadastronaut]

ive run out of 1n914's...

will the 1n4148's be ok?...

[Perrow]

I hope so, I used them out of old habit.

[deadastronaut]

i guess i'll find out today, just finished up 2 pcbs.... arghhhhh more debugging!..


EDIT:  tried 4558's in both, no chorus...whacked 072's in..perfect!!!..lush chorus on 1.....weird eh!.


the one with the 1n4148 isn't chorusing yet though...no lfo yet....hmmm..

edit: found a 1n914....still not chorusing, no lfo..

[deadastronaut]

okay round 2 of debugging...on 3rd build...tonepad small clone!..

same thing, sound no chorus: but getting rumbly hiss when using trim halfway...no lfo, no fluctuating voltages....
ive checked the pcb, cleaned trace gaps under magnifier....swapped 3007/4047..358..

Q1  2N3906

C  0.00
B  3.27
E  3.92

Q2 2N5088

C  8.85
B  5.26
E  4.69

Q3 2N5088

C  8.85
B  8.80
E  8.18

MN3007

1  8.18
2  4.07
3  4.47
4  0.00
5  0.00
6  4.06
7  5.23
8  5.21

4047

1  7.98
2  0.12
3  6.82
4  8.18
5  8.18
6  8.18
7  0.00
8  0.00
9  0.00
10  4.06
11  4.07
12  0.00
13  8.01
14  8.18

358 TOP OPAMP

1  1.73
2  1.64
3  3.55
4  0.00
5  1.72
6  1.95
7  1.65
8  8.85

072 BOTTOM OPAMP

1  4.39
2  4.39
3  4.28
4  0.00
5  4.38
6  4.39
7  4.39
8  8.84

[deadastronaut]

bumpy bumpy!...^   

just a note: the output on the chorus is much louder than bypass..needs a trim/resistor on output!...

[Govmnt_Lacky]

Hey Rob,

One thing is for certain.... your LFO is dead! Where's the wobble mate?

Did you jumper Ra?

My suggestion is the usual. Component values, capacitor orientation... especially around the 358. Doubt its a solder joint  

After that.... I would try a new 3007.

Good Luck  

[deadastronaut]

cheers man,

yeah jumpered, built exactly the same as 2 others...this one is just being a pita...and its my one.. typical!..

swapped 358,3007,4047...no lfo...hmmmm....

[Perrow]

built exactly the same as 2 others...

no

[deadastronaut]

ha ha yeah obviously not..

[Govmnt_Lacky]

Resistor color codes around LFO circuit 

[deadastronaut]

heres a finished one...need to sort mine out still though!...

[deadastronaut]

ok i'm back on debugging my chorus...still not getting lfo, not sure why

i checked my working voltages on the 358 and compared to the non working voltages...there really can't be much to go wrong looking at the circuit..

working voltages  and non working voltages on the 358 top opamp

1  0.94-2.24.....non  1.73
2  3.58       .....non   1.63
3  3.55       .... non   3.55   ok
4  0.00       ....non    0.00   ok
5  1.16-2.98 ...non    1.71
6 1.95       .....non 1.95     ok
7  0.03-7.52...non 1.63
8  8.86                 8.86      ok...

so the problem is around 1,2,5,7 pins....hmmmm...ive double checked values around it , but no lfo.....any more ideas?..

[deadastronaut]

i just noticed a weird thing, when i cut the power to the pcb it tries to chorus just as the signal dies...hmmmm..

so it sounds like it wants to do it....weird!..

[jamamoto]

heres a finished one...need to sort mine out still though!...

Hi, where you put LED on pcb, there arent on pictures

[deadastronaut]

Morning....


That is a tonepad chorus....not a zombie chorus...

Take an led via a 1k resitor to ground from the lfo out....

If i remember correctly....

[jamamoto]

which PCB is for that, for tonepad chorus

[deadastronaut]

I think its the "heladito" ...