I just finished the aquaboy w/ the v3205 chip, and used the trimpots to adjusted accordingly (cleanest repeats, lowest clock noise, longest delay time), and it was sounding great. So I took it off the breadboard and wired it up in the actual enclosure, and when I was finished it just had a sort of reverb/chorus sound to it with no actually repeat sounds. So I rebiased it after that and it was again sounding good w/ nice, clean, 300-350ms repeats and nice loud repeats... until today, I plugged it in and it's doing just the reverbish sound again, so I reset the bias knob, clock, and delay time trimmers, and again, it works great. I was wondering if anyone has had this problem yet, and/or any fixes for it? I don't know why it would "reset" like this or whatever... but I don't wanna have to do that every time I use it... Also, could messing w/ the repeats knob alot (sending it into oscillation craziness) cause this to happen? Anyway, any help would be appreciated.
It sounds to me like your voltage into the board might be fluctuating. What kind of power supply did you use on the breadboard and what PS are you using with the final build?
Actually, I used the same adapter for both the breadboard and the actual pedal, so I don't think this would be an issue... but maybe something is weird w/ the power on the board somewhere? IDK, the only change I made from the stock layout for the v3205 version is I changed r31 to a 33k instead of a 22k to make the repeats "tame" until the end of the pot rotation... Also, I remember changing r15 to a smaller value to make the repeats cleaner, something like 33k, I believe... and that worked as well. Maybe that has something to do with it though? Not sure but, it sounds great when it's working
Oh, another question... how bad actually is it to not socket the chips on this build? because I didn't and I'm afraid maybe the v3205 is acting weird as the result of that... It's just weird because it was working flawlessly, now I can't get it dialed in again (it seems that I can't even bias it to pass delay now)... IDK, any other suggestions?
You can get away without using a socket, but it's not worth chancing it. They are pretty sensitive to soldering heat.
I don't think this is your problem though since you did have delay previously.
It should be a set and forget once you get it calibrated.
Can you give us the voltage at the bbd pins.
How are you calibrating? Are you using an audioprobe to calibrate (listening to pin 3 or 4) or are you just listening to the output of the engaged effect?
Josh
Well, I haven't checked the voltages on the bbd, but I will...it just doesn't seem likely because I had the effect working perfectly b4, and I haven't messed w/ anything on the board that would screw with the voltage on the circuit)...
As for biasing I just did it by ear, w/ the pedal engaged through my amp. How would I go about biasing w/ an audio probe on the bbd pins?... like, what would I be listening for?
Also, thought maybe I should mention about where I have the trimmers set when the pedal is working, so I can be sure these are semi-normal settings, typically...
1. Bias - I found that when I set it a little more than halfway, I got the cleanest repeats. Any lower than 12:00 (halfway) the delay cuts out and above about 2:00 it cuts out as well.
2.cancel - Same as bias, when I set it a little past 12:00 it gets the cleanest sound w/ the least clock noise (sort of depends on where I have the clock set though)
3.clock - I set this to have the longest repeats w/ the least amount of noise introduced... around 12:00 I found to be the most usable range. Any higher than that though, and it starts getting a high pitch, sample rate reduce kind of sound (when the delay pot is turned fully clockwise).
Does this sound like normal operation for this circuit?... Also, would wiring it up into the enclosure have anything to do w/ it, like... the amount of wire I use for the pots or input or output wires or anything like that... would any of these things have the effect of making the delay signal stop working, until resetting the trimmers?... thanks for the advice given so far btw, guys... appreciate it.
The trimmers are around where they ended up on my build, except the clock which I've got about 2/3 clockwise on a single turn trim.
Don't rule out anything. When boxing things up, a weaker solder joint that worked previously can easily fracture when your handling the board and wires etc... Voltages are always a good start regardless, plus I have no idea how hot your running you bbd.
First, turn your delay time pot to around noon and the feedback to fully counterclockwise so you would only get one repeat.
Next, take your audio probe and listen to pin 7 on the v3205 to make sure your still getting a signal to the bbd.
If you don't have a signal we need to troubleshoot elsewhere.
If you do have a signal put the probe on pin 3 or 4 (it doesn't matter which) of the bbd. You should be able to slowly turn the trim until you get your delayed signal. You will get some nice squealing along with the signal that will peal paint so keep your amplification device low until you get a feel for the volume.
Let us know what you find.
Good Luck!
Josh
Ok, will do... thank you, sir
Just got around to messing w/ the delay again....can't get it to work at all, though just getting a reverb type sound again, and the oscillation sort of works if the repeat knob is all the way up... but no repeats are coming through.
heres the voltages im getting from the bbd v3205
pin1 (gnd) - 0 v
pin2 (cp2) - 2.26 v
pin3 and 4 (out1 and out2) - 3.16 v
pin 5 (Vdd) - 6.25 v
pin 6 (CP1) - 2.63
pin 7 (In) - 3.15
pin 8 (Vcc) - 5.20
are these normal voltages for this bbd?
I messed around w/ putting the audio probe to pin 7... I can hear my guitar signal but I'm not getting any delay, just a slight reverb kind of sound. Also, tried using the audio probe on pin 3, then dialing the trim pots to different spots to try and get a delay out of it... again, just getting a slight reverb sound and laser sort of sounds when turning the bias trimpot from counter-clockwise to fully clockwise...
Ive also double checked the parts and layout to make sure I have all the proper values, right orientation for polarized caps, diodes, ect... and everything was fine... again the only deviation from stock values was r31 I changed to 33k instead of 22k for the repeat knob to oscillate later, and I changed r15 to a 51k from a 100k to make repeats less distorted.
Also... just noticed, w/ the pots - the mix pot is effectively mixing in the reverbish sound and seems like it's funtion correctly, and the repeat knob goes into oscillation when turned all the way up, meaning it's probably working right... but the delay knob just makes a warble kind of sound when I turn it up and down or when I touch the lugs of the pot w/ my fingers.... not sure if this helps at all, but... I'm just experimenting, trying to figure out whats wrong w/ it...
IDK, any other suggestions/help?
I think your problem lies somewhere with the clock/or time pot. Where is the clock trim? I'd set it close to max to start off. You can lower it to limit the clock noise once you get it functioning. With only one bbd this delay borders on a reverb because the delay time is so short. Could you post your voltages for the clock IC as well. Your voltages for CP1 and CP2 look low. Plus some good pics may help.
Josh
Even with the clock trimmer all the way up w/ it biased in the area where the reverb sounds the cleanest it still isn't passing any repeats. I can't get any kind of delay out of it at this point... when it was working (wired up in the enlcosure), I was messing w/ the repeats and oscillation knob and thats when it just suddenly stopped working... really frustrating, to just work perfect like that, then stop, now I can't get it to delay at all.
voltages for the clock IC :
pin1- 5.18v
pin2- 2.44v
pin3- 0v
pin4- 2.46v
pin5- 2.55v
pin6- 2.58v
pin7- 2.73v
pin8- 0v
If your getting reverb it is passing a delayed signal its just really short. Where is you clock trim set?
Oh, ok... Ive been trying the trimmers in various spots for like an hour now and can't get it to delay besides that reverb sound I mentioned...but when I'm turning the clock trimmer it's making a weird warble noise in certain spots but it's still not delaying... when the delay was working properly I had all the trimmers set around noon, though. Now, that isn't working at all either
Sorry, I didn't see your voltages for the clock on my iphone browser. But pin 8 on your clock should not be 0V.
Concentrate on the components in the bottom left of the schematic it seems like something is shorting to ground. Check c22 again. Something is definitely wrong in this area around the clock IC.
Ok, my fault, I just checked it again. Pin 8 is actually 5.3, before I wasn't touching the dmm lead on the pin properly.
Also, here are some pics of the board I attatched...
[attachment deleted by admin]
here's a better one of the top...
[attachment deleted by admin]
Your clock signal is a little weak like I mentioned earlier. Maybe try changing the value of r19 to get a little more juice to the clock. Just make sure your don't give it more than 9v because the bbd voltage is affected by r19 as well. The datasheet says the clock can up to 12V and the bbd 8v, but I've been running my v3205's at 9v with no problems.
I really don't know if this will help but it's worth a shot.
I'm still thinking there is a solder joint somewhere that weakened during the boxing possibly. Do you have continuity from the underside of the board to the leads on your clock trim. Maybe it tugged a joint a little while handling?
Josh
While there is still a possibility that theres a weak joint somewhere from handling and boxing it up, this is the first thing I thought of when it stopped working, and I have since resolderd the pots and made the leads shorter on them, and also resoldered all the pads for the pots on the board, and all the wires to the board as well...
Thanks so much BTW, for responding so quickly and being so helpful... really appreciate it :)
No problem. You'll get it figured out. I would try adjusting your clock/bbd voltage though. I just used a 9v regulator in r19 to keep the supply constant. Depending on your power supply the voltage can vary from one 9v wall wart to the next.
Oh alright, well... I just changed r19 to a 1k instead a 1.5k to no avail... still exactly the same, not passing a any kind of delay but has a reverb sound. It's really weird, the clock trimpot isn't really effecting the sound at all, except in one spot (about 9:00), it just kind of does a warble sound. It almost seems like the delay pot and clock trimmer aren't working properly, somehow. Don't know what else to try though...
Was wondering... would it be wise to use a 5v regulator instead of a 9v one... reason I ask is, they have 5v and 12v regulators at radioshack, so I wouldn't have to order online and wait, to work on it more. Also, what are the odds of this even fixing my problem?
I don't think that the regulator is necessary right now. There must be something going on in the E1 area of the schematic. You never mentioned what clock you were using. I assuming it's a v3201.
Do you have enough access under the clock trimmer to check continuity between each trimmer leg and the component it traces to?
Yeah, my multi-meter doesn't have continuity test on it though so... can I tell by using ohms or voltage somehow? Like... would I just set it to ohms and check between the legs, and if I get a reading, I have continuity?
use the ohms setting on your dmm, if it shows OL there is no continuity
Check continuity for example between leg 1 of the trim and r21. If you show a numerical value you have continuity.
ok, from bottom of leg 1 of the clock trimmer to the top of r21 resistor, Im getting continuity... my DMM is saying around 15k or something.
From leg 2 (middle leg) of the clock trimmer to r22 I'm also getting continuity.
From leg 3 of clock trimmer to leg 6 of the clock IC, it's going sporadic w/ numbers and a negative symbol down (up?), to zero, back and forth.... not sure if this is because it's an IC and not a resistor, or what.
Also, between the legs of just the trimmer itself, it's not giving me a steady reading... it's just being sporadic
also, yeah... I'm using the v3102 for the clock IC
As long as it didn't say OL your fine.
Hmm... The quick check to rule out the clock ic would be to swap it out, but unfortunately it's not socketed. It just seems that since it did delay that it should be something else.
It acts like when the clock trim is at the minimum setting. You could go through and carefully reflow solder through the components in question to rule out a bad joint in the clock section... Just take your time with the IC. Quickly do one leg and wait for a while before doing the next leg. Be careful not to get the board to hot. Just do one joint every 20 seconds or so.
I'm not really sure what else to say ??? Good luck! Sometimes, taking a break is the best thing to do for a problem build too.
Josh
Yeah, I know what you mean....
I did reflow solder throughout the entire board, but still nothing... maybe I'll just have to accept it's broken... just sucks because all the parts on this board seem fine, but will be wasted and $ for the chips and everything. Well, thanks for your help anyway... I'll probably experiment some more w/ it later.
You'll get it. Patience and persistence are your friends. Just work on it in moderation. Sometimes the answer will come a day or even month's later. It's not wasted money because we'll get it ;D Maybe someone else has something better to try as well.
Josh
K, thanks man... appreciate all your help today!
I ordered all new chips, and I'm gonna desolder the old ones, socket the new ones (v3205, v3102), and see if that fixes my problem... if not, I'm probably just going to re-build a new one. Personally, I think it's the clock IC thats bad, and I'm pretty sure that this should fix my problem.
Since your going this route. I'll offer a suggestion for removing the clock IC. You'll most likely finish off the clock desoldering whether it was working or not. The best way to remove it is to just cut each pin on the IC where it meets the black plastic. I use flush cutters, I don't know if this is the proper name for them. Then you can desolder each pin individually without heating the board up to much. Also, if you had access to an oscilloscope you could see if the clock was sending out the proper signal.
Josh
K... just changed the clock IC, I ended up desoldering each leg individually (I did it before seeing your post about clipping the legs, I don't think I heated it too much, though)... So, it still isn't working w/ the new clock ic socketed and inserted in the socket... same thing, just reverb sound... I guess I'll take it back out and socket the rest of the chips, then try it out... don't really know what else to try! I was wondering though, if the delay pot was broken, would this cause it not to adjust delay time, resulting in just that reverb sound no matter where the pots turned? I think this might be another option because the delay pot isn't changing the sound of the delay, except for at the very begginning of the pot rotation, it makes a little warble sound. Also, I was thinking, is it likely at all for a trimpot to go bad from turning it too much or something? IDK, just trying to rule some things out.
It could be a intermittent (now bad) solder joint on the pot or board. I've had this happen on a pcb mounted pot before. Took me a little while to find that because visibly it looked good. Component failure is rare for things like pots, resistors, caps. I've had a pot with a bad taper in my carbon copy delay but this was a widespread problem. The wearing out of the trim pot is unlikely as well. If you wanted to check the delay time pot you could always just pull one of the leads off and check it.
Josh
what should the resistance be? and By "pull one of the leads" you mean desolder one leg of it and probe it w/ the multimeter and the other side to one of the other legs? How would I know if it's bad or not?... Sorry, I'm not terribly educated w/ pots and testing them for stuff... a little explanation would do me good, thanks
You can remove the wire from lug 1 or 2 of the pot. It just needs to be taken out of the circuit to get an accurate reading. Put you dmm in the ohms setting and place one lead on lug 1 and 1 lead on lug 2. (color of lead does not matter)
With the pot turned fully counterclockwise it should read 0, at fully clockwise you should be around 1MB. The tolerance on most potentiometers is 20% so take that into consideration that it could be as much as 200kB difference and still be within spec. Although it is usually much closer than that.
Josh
Hey, thanks... finally figured out what it was after all this time, and I would have never guessed it... the delay pot was bad!!... either, it was defective, or somehow I messed it up from heating it up too much or something. This is definitely a first for me!
Anyway, thank you so much Josh (Gtr2), for helping me through all this, and I really appreciate it... let me know if you ever need help/advice on anything and I'll be glad to return the favor... God bless!
Awesome!!! Glad you got it working. ;D
Josh