Hi guys,
I finished the current lover, tested it a few minutes. Roughly biased it.
Boxed it.
Plugged it, rebiased it.
And boom: biasing was not easy & when i turn the rate pot, i have this incredebly weird modulation: some kind of random detune on what i play.
I unboxed the pcb, checked for obvious stuff. Changed the bias trimmer. (mostly to do something)
Still the same.
It's 3:20 am now in Paris, so i'm going to bed and will check & list here the IC's voltage.
In the meanwhile, anyone have a brilliant idea?
Random Detune...you'll have to be a bit more specific, constantly across the sweep? At the ends of the sweep? Is it dropping out or does the note wobble while flanging?
I know with my first build I biased it too hot and got drop outs at the end of the sweep, the trimmers are slightly interactive so playing with them may help.
All else fails, post your voltages and audio probe.
Constant yes: as soon as the rate pots moves a bit, it's immediate.
If i turn the clock trimmer counter clockwise, the detunes disappear but so does most of the sweep.
Another weird stuff: i have some kind of distortion with the flange.
At 2 o'clock of the bias trimmer, this is just what i have: distortion and nothing else.
Distortion is normal on the bias, BBDs have a small window where they work and a smaller one witout distortion without using a precision trimmers, it should generally be about half way.
Out of interest 3207 or 3007? It is possible to have a working BBD but have it damaged, poor Static handling can cause this.
I do recall some issue that could occur with the diode in the lfo/clock portion of the circuit... i'll have to dig deeper, your voltages will really help though.
Modulation in the signal suggests this is a lfo/clock based issue.
Thanks Scruffie!
This is the MN3007 version.
Will post the voltage tomorrow, it's now almost 4am.
So here we go:
4558:
Pin Voltage:
1. 4,56
2 4,56
3 2,28
4 0
5 4,12
6 4,54
7 4,52
8 9,08
MN3007:
1 9,07
2 4,52
3 4,45
4 0
5 0
6 4,53
7 4,86
8 4,84
LM311
1 0
2 1,2 - 4,5
3 2,14
4 0
5 9,08
6 9,08
7 8,6
8 9,08
4013BE
1 4,53
2 4,53
3 8,6
4 0
5 4,52
6 0
7 0
8 0
9 0
10 0
11 0
12 0
13 9,08
14 9,08
CD4049UBE
1 9,06
2 4,53
3 4,49
4 4,52
5 4,53
6 4,53
7 4,53
8 0
9 4,52
10 4,52
11 4,52
12 4,51
13 0
14 4,53
15 4,45
16 0
LM324N
1 4,54
2 4,54
3 4,12
4 9,08
5 1,25 - 1,8
6 1,25 - 1,8
7 2,20 - 4,90
8 1,2 - 7
9 4,08
10 3,4 - 5,1
11 0
12 4,5
13 4,15
14 3,20 - 4,90
I'm uploading a video (a bad one) of the sounds i get from it to youtube.
Will upload the link in a few minutes.
Thanks in advance for your help.
Hmm... there's something wrong with your 4049 voltages I think... Pin 12 should be around the same voltage as the rest of the pins and pin 13 should be NC.
The clock voltages on your MN3007 are also a little weird... Pins 2 & 6 should be near enough the same.
Pin 4 should be near supply voltage too...
Pin 3 of your 4558 is low, but this could be your multimeter giving an incorrect reading due to impeadance as the other voltages on it seem fine.
Look around the 4049 & 3007 for bad joints or shorts.
And here's a sound sample.
http://www.youtube.com/watch?v=roaPLahzR9Y&context=C30cc84dADOEgsToPDskIpLiuhAcsvzDBgYa5fx45j
Quote from: Scruffie on January 08, 2012, 07:26:51 PM
Hmm... there's something wrong with your 4049 voltages I think... Pin 12 should be around the same voltage as the rest of the pins and pin 13 should be NC.
The clock voltages on your MN3007 are also a little weird... Pins 2 & 6 should be near enough the same.
Pin 4 should be near supply voltage too...
Pin 3 of your 4558 is low, but this could be your multimeter giving an incorrect reading due to impeadance as the other voltages on it seem fine.
Look around the 4049 & 3007 for bad joints or shorts.
sorry, i had misread my notes & inverted values for right side pins of every ICs, edited the voltage & going to recheck values on the mn3007.
ok, checked the voltage of Pin 4 of the MN3007 and have 0V confirmed. Retraced it on the PCB and finally remembered this note from the doc, so i'm guessing 0V is ok:
"MN3007 – Omit D4, D5 and C5. Connect the square and round pins of C5 together via a jumper. This does two things:
connects pin1 of the MN3007 to VC via a 100R series resistor f or (nearly) f ull voltage operation and connects the VGG pin
of the chip to ground"
ok, did a bit of wandering on the pcb with an audio probe.
The "detune" modulation gets out of the MN3007 outs. Pin 7 & 8. BUT it depends on the clock trimmer position:
If full counterclock on the trimmer is 7 o' clock, the detunes start at 8:30.
With the clock trimmer between 7 & 9, i have kind of chorus sounds but no flange.
Anyone?
Hi guys, i read most of the topics on diy about Thomequee's electric mistress adaptation. Did not get most of it obviously.
Then, i just stared at the pcb and i just have no idea what to do next.
At this point, any idea to continue troubleshoot will be welcome. I will even take a suggestion to kill a black rooster during full moon seriously.
Have you read all the tips and ideas http://www.madbeanpedals.com/forum/index.php?topic=902.0 (http://www.madbeanpedals.com/forum/index.php?topic=902.0) there?
Jacob
Almost, i think.
What i did:
I checked every resistors value with a DMM and taped them to the bom.
Did not check capacitor value (did not have a capacity meter), but double checked the value on the capacitors & taped them to the bom.
I tested it before boxing it. I think it was ok, i had some noises but i assumed that was because it was out of the box.
Boxed it.
Wired it.
Plugged the power supply with the wrong polarity for a few second. (plugged, switched, led being off, removed the power supply)
Had this weird detune stuff.
Checked the pcb for bad solders
Tried another 4558, just in case.
Checked all ICs.
Played with the trimmers, checked the value of the trimmers. Changed the bias trimmer (measured at 80k instead of 100k)
What i noticed: at some point, i just had no effect at all. I removed the MN3007 replugged it, same behavior with the detune stuff.
Posted all the voltages on ICs.
Used the audio probe, checked in & out of the 4558 & MN3007.
I could check all components value again & i probably will. But i'm pretty confident this is not the issue.
Could the reverse polarity a few seconds have damaged one of the ICs despite the diodes?
So that's weird. If you had it working outside the enclosure that immediately makes me think that something is either grounding against the enclosure OR there's a problem with your power and wiring. Take it out of the box, does it work again?
Jacob
It has been out as soon as i realized i had an issue and it was not related to the wiring.
Is there anyone out there that has a working current lover and would not mind to share its IC's voltage?
Next step for me would be to change all the ICs just in case. The MN3007 price hurts a bit though.
Hi guys,
Today i replaced jrc4558, cd4049, 4013 & lm324 and no changes.
Should i try to replace MN3007 or for the same price order another PCB?
What do you think?
I think that since it was working before, you need to figure out what changed. Really, I'm not sure what else to tell you. You could try replacing your MN3007, but depending on where you got yours from it may not be the problem.
Jacob
The MN3007 is coming from musikding.de a usually very reliable source.
And that's the thing: Nothing changed. The only significant event i can think of is the 3-5 seconds i plugged the inverted polarity power supply (the one i use for the cap meter i built)
This is why i'm thinking maybe a damaged chip.
Will put this thing in a box & wait for the devil that is sitting on it to go away.
Thanks Jacob.
Have you checked your polarity protection diode? If you did that, even briefly, that's what could have caused the problem. I don't know if you mentioned that already or not, but hearing that could change everything. Check D3 and the other parts in the power section.
If that's not it, I don't know what to tell you except unsolder all your wires, put a new MN3007 in, and redo the wiring to see if that helps.
Jacob
Yes i wrote it before but i guess i wrote a lot and surely too much.
I'm struggling with the power section. I don't get what to do with this part of the schema for instance:
(http://djaaz.free.fr/power.jpg)
what am i supposed to check?
I checked CD4013 & LM324 already
Suppose i should check c20, LM311, D2, D3 & D4 as well?
and then this silly question, how to check that a diode works? Using a dmm in ohmmeter mode?
I have built a working CL.
I can do the voltages but require ecookie as payment :D
I just finished up my PCB and can make it sound the same way yours does in the video by messing with the bias and clock pots. It actually can do some pretty interesting stuff at the bottom of the sweep when the trims are set really wrong. I'm still dialing it in and bias/clock each seem to move the others sweet spot. Pretty sure it was there for a few minutes until I screwed with it attempting to 'improve' things :(
I can get it most of the way there but have some trouble reconciling the trims with feedback and range both above around 80%. Then again that might be what happens when you start turning knobs all the way up!
Just a thought, good luck man.
HEre you go, Lace. And thanks!
(http://i42.photobucket.com/albums/e309/hametsuj/E-Cookie.gif)
And thanks Lloyd17.
I played with the trimmers yesterday and indeed having the clock trimmer all the way down between 7 & 8h30 makes the "detunes" disappear but so does the flange.
The bias trimmer needs to be almost all the way up to have some effects without distortion.
ill post voltages today
Thanks guys!
Any interest for another video, may that help?
Kind of a stumper. I'm leaning towards a biasing adjustment being needed, too. Sounds like the LFO is doing what it needs to do, and the MN3007 is doing it's thing, but it won't bias properly. I don't think you need to replace the MN3007.
First thing I would do is socket C18 and try some other values there...15pf, 33pF, 47pF. This should help "reset" your clock trimmer. Try that and let us know what you find.
From memory Im keen to agree with bean and lloyd
I found when I was building mine I messed a lot with the trimmers, and could get some really odd modulation going on. Could be normal. Listening to the video you posted I think it sounds normal kinda (!)
Not sure, depends what everyones expectations of the circuit are.
Thanks for the cookie
Here the goods
supply - 9.4V
LM311
1-0
2-varies
3-varies
4-0
5-9.2
6-9.3
7-varies
8-9.2
MN3007
1-9.4
2-4.2
3-3.6
4-0
5-0
6-4.6
7-3.6
8-3.7
JRC4558
1-4.9
2-4.7
3-2.3
4-0
5-4.2
6-4.7
7-4.7
8-9.3
4049
1-9.3
2-4.5
3-4.5
4-4.5
5-4.6
6-4.5
7-4.6
8-0
9-4.6
10-4.4
11-4.6
12-4.6
13-0
14-4.7
15-4.7
16-0
4013
1-4.6
2-4.6
3-7.4
4-0
5-4.6
6-0
7-0
8-0
9-0
10-0
11-0
12-0
13-9.2
14-9.2
LM324
1-4.6
2-4.6
3-4.2
4-9.2
5-1.4 - 2.0 ish
6- varies
7- varies
8-jumps 0.6 up to 7.5 and back
9-4.2
10-varies
11-0
12-4.2
13-4.3
14-varies
Hope that is of use
id say your voltage readings are largely the same to mine
time to play with some trimmers me thinks.
Replacing C18 nailed it! Thank you guys for the help.
I socketed it & then tried a 10pf & then with 15 pf and it's working again.
That's crazy because it worked at first try and i don't know what happened when i boxed it.
Anyway, i now have some tiny but ugly distortion in the signal and i could not get rid of it.
The bias trimmer is all the way up the clock, the clock trimmer is almost all the way down.
T1 is at 11.
Will change C18 to higher value tomorrow & see if it help with the distortion.
Thanks again for all your help!
You can also socket R12 and try a lower value. It may be that your particular build wants to bias a little bit closer to 15v than it can get with that 82k resistor there.
Thanks Brian.
Was thinking about giving a bit more room to the trimmer by changing the resistor value around it.
What about using a road rage to actually bias it for 15V?
Sorry for the late reply. I had a road rage built up for my dirtbag which is now waiting for chips so it went right into the current lover during boxing. Fixed all my bias problems right up: nice and clean, nice and deep flanging and over the top feedback without oscillation with the trimmers resting in a much more neutral position. The circuit sounds far far better at 15v than 9v with 3007 chips imo.
Quote from: lloyd17 on January 24, 2012, 04:29:25 AM
The circuit sounds far far better at 15v than 9v with 3007 chips imo.
what chip you got in your roadrage circuit?
Will a max1044 work? colour me interested in running mine at 15v
If its built for 9v, is it simply a case of adding the chargepump and connecting the +DC to the output of said circuit? Thanks
(obviously all caps need to be at least 16v I spose, or 25v to be safe?)
Quote from: lloyd17 on January 24, 2012, 04:29:25 AM
Sorry for the late reply. I had a road rage built up for my dirtbag which is now waiting for chips so it went right into the current lover during boxing. Fixed all my bias problems right up: nice and clean, nice and deep flanging and over the top feedback without oscillation with the trimmers resting in a much more neutral position. The circuit sounds far far better at 15v than 9v with 3007 chips imo.
Thanks for the feedback, i'm actually waiting for another roadrage & the 1n5817 diodes to arrive but i could also use the board sitting there for the dirtbag's roadrage that is also waiting for their chips.
I should say it sounds much better at 15v vs 9v due to easier biasing. I was able to clear out all of the distortion minus a bit of edge on the sweep when depth and feedback are way up. I'm pretty sure that's normal though since I have the feedback trim set just under oscillation. At 9v the sweep always had a grind to it that could not be dialed out with the trims.
For the road rage I use 25v caps, LT1054IP and KA7815AETU all from Mouser.
Ready to box!
My build is a complete different animal with a roadrage pouring 15v in it.
I played with different values for C18 cap and finally put back the 22pf. I could not find a distinctive value there, from 10 to 47: not easy to tell. Rebiasing it makes it difficult anyway.
I guess i need to play it now and change this value from time to time but i'm happy as it is and i'll probably forget about it.
I really like this one, Brian, Thanks!