Hi, I've got 3 of each type of MN3007 and MN3101 that are all from different but trusted sources. the mn3101's i have tested in a delay and work well. the MN3007's are known to work from a past chorus build. I cannot for the life of me work out whats going on, could someone please cast an eye over my board and check the voltages I'm getting? thanks in advance.
(http://i335.photobucket.com/albums/m447/thorpy6/pbguts.jpg) (http://s335.photobucket.com/user/thorpy6/media/pbguts.jpg.html)
(http://i335.photobucket.com/albums/m447/thorpy6/pbguts2.jpg) (http://s335.photobucket.com/user/thorpy6/media/pbguts2.jpg.html)
(http://i335.photobucket.com/albums/m447/thorpy6/porkbarrelguts.jpg) (http://s335.photobucket.com/user/thorpy6/media/porkbarrelguts.jpg.html)
Voltages are as follows:
TL062cp
1=8.58v
2=0.3mv
3=8.57v
4=0.4mv
5=0.3mv
6=6.25v
7=8.58v
8=9.25v
JRC4558
1=4.45v
2=4.46v
3=4.45v
5=4.46v
6=4.45v
7=4.45v
8=9.25v
MN3101:
1=9.15
2=4.66
3=0.4mv
4=4.71v
5=315mv
6=8.15v
7=2.5v
8=0.619
MN3007
1=9.16v
2=4.72
3=3.76
4=0.62v
5=0.4mv
6=4.68v
7=3.74v
8=3.74v
Hopefully this is enough for a kind hearted individual to help me fix this bugger!!
When you activate the effect, do you get dry signal or nothing at all? Just off the top of my head, you should have 0V on pin 4 of your 4558. Look for a solder bridge there. Nevermind -- misread.
There's a little fleck of solder? By the 9v in / ground pad
Got the jumpers under your mn3007? And what does it do? I don't see it if you already stated the exact problem.
Sorry, I thought I'd described the issue- my error. The pedal works in bypass. When the effect is activated I get dry signal but no wet signal. The rate and depth knobs don't really do anything.
Update- I found a 330n cap where a 3n3 was and since changing that I have the ability to dial the trimmer into something but the chorusing effect still isn't there. The depth knob seems to do "something" since the cap change but the rate still doesn't work.
Overall it seems to want to do the wet thing but it just won't. The jumpers are set for mn3007.
Just a thought, does it work if you take it out of the box? Easy to short underneath and not realize it.
Quote from: thorpy6 on August 21, 2014, 05:32:05 AM
Sorry, I thought I'd described the issue- my error. The pedal works in bypass. When the effect is activated I get dry signal but no wet signal. The rate and depth knobs don't really do anything.
Update- I found a 330n cap where a 3n3 was and since changing that I have the ability to dial the trimmer into something but the chorusing effect still isn't there. The depth knob seems to do "something" since the cap change but the rate still doesn't work.
Overall it seems to want to do the wet thing but it just won't. The jumpers are set for mn3007.
Audio probe OR check all the other values OR reflow....happens to the best of us...
It doesn't do anything cause your LFO isn't moving, dig there.
Which section is the lfo driver
The TL062.
Can I use a different type of chip? I have a bag of tl062cp chips and have tried two
LM358 work well, as do LM1458.
You sure it's the chip though? Checked all the values, reflowed the joints etc.
i've checked all the values, i did do all the joints but I'm going to redo them now.....
ok, reflowed absolutely everything (again) taking particular care around the LFO. i noticed what may have been a microscopic solder bridge near the lfo. fixed this and now it is working as expected. very nice it is too. many thanks for the support guys.
:) Congrats.
Quote from: thorpy6 on August 21, 2014, 06:57:09 PM
ok, reflowed absolutely everything (again) taking particular care around the LFO. i noticed what may have been a microscopic solder bridge near the lfo. fixed this and now it is working as expected. very nice it is too. many thanks for the support guys.
Happens to the best of us! I'm glad to hear it!
Good deal!