UbeScreamer help, please

[dfeweer]

First time posting but I have been lurking for a while.

I am having some problems with my UbeScreamer and I am looking for some help.

Some background...

I wanted another overdrive sound but I did not want to build a variation on the Tube Screamer (example: Landgraff "Dynamic OverHype", Clay Jones OverDrive, etc.) since I already own an Ibanez TS-9 TubeScreamer

Therefore, I decided to build the UbeScreamer from ROG. The link to the UbeScreamer from the ROG site is here.

I used the PCB that is located on gaussmarkov.net. The direct link to the project is here.

Here are some symptoms:

1)I does pass some signal, but the signal is relatively weak and sounds kind of raspy. I should also ad that the decay of the notes is strange. When I hit a note I get some overdriven sound, but as the note decays, it starts to get kind of farty sounding then it abruptly fizzles away. I actually get a laugh when I hear a note fizzle away. But then it makes me sad that my pedal does not work. LOL.

2) The voltages at the all of the pins is as follows:
             Pin 1-7, 9-12, and 14: 7.6V
             Pin 8: 0V
             Pins 13, 15, 16: Not Connected
             I emailed Sebastian from ROG and he said, and I quote:
             The 4069/4049 stages are self-biasing. This means every input and 
             output should be somewhere between 4 and 5V when the supply voltage is 9V.

From #2 above, there is obviously something wrong but I cannot seem to find what the problem is.

I have double, triple, and quadruple checked my resistor values and they are 100% correct. I have also checked my capacitor values and they are also 100% correct.

I have put the board under a magnifying glass and I am confident that there are no shorts and all of the solder connections look good (i.e. no cold solder joints, etc.).

Any hints or tips would be appreciated.

Thanks in advance.

dfe

[oskar]

Hi and welcome!
It saddens me to hear about your hardship and I wish nothing more than to offer some kind of relief   

1)I does pass some signal, but the signal is relatively weak and sounds kind of raspy. I should also ad that the decay of the notes is strange. When I hit a note I get some overdriven sound, but as the note decays, it starts to get kind of farty sounding then it abruptly fizzles away. I actually get a laugh when I hear a note fizzle away. But then it makes me sad that my pedal does not work. LOL.

2) The voltages at the all of the pins is as follows:
             Pin 1-7, 9-12, and 14: 7.6V
             Pin 8: 0V
             Pins 13, 15, 16: Not Connected
             I emailed Sebastian from ROG and he said, and I quote:
             The 4069/4049 stages are self-biasing. This means every input and 
             output should be somewhere between 4 and 5V when the supply voltage is 9V.

If the pcb isn't properly grounded, like when you forget to insert a plug in the input, then you will find V+ or close to all over the place... But your ground is measuring 0V...     

First thing is to audioprobe it to see where along the sound chain things are getting funky...



oskar

[gez]

Is the chip the right way round?

[tednet]

sorry for hijacking the thread, but I build the ubescreamer and sadly I am not getting any overdrive at all :/ Crispy clean only, no matter how much I turn the gain knob. The tone knob, I am not sure because I have not put it into an enclosure yet and its kinda hard to turn and test, but I think that is working. So what do you think the culprit might be? Any ideas for tests?

[gez]

sorry for hijacking the thread, but I build the ubescreamer and sadly I am not getting any overdrive at all :/ Crispy clean only, no matter how much I turn the gain knob. The tone knob, I am not sure because I have not put it into an enclosure yet and its kinda hard to turn and test, but I think that is working. So what do you think the culprit might be? Any ideas for tests?

Wrong value for one of the resistors that sets gain?  Follow the general advice when things don't work (isn't there a sticky above?).  If all else fails, post voltages and schemo (probably best in a new thread, so as not to confuse things).

[zeeman]

I have a PCB of this and have been meaning to get to it.

I did a search on this forum and I could not find much about this circuit (it sounded good on the ROG website which is why I had a PCB made).

Do we know if this is a verified (as in others have built it and they have it working) layout?

gez,

Is the chip the right way round?

Without looking at the pinout of the IC, I would assume that if it was in backwards, it would start to smoke. Since dfeweer does not say his IC is getting hot, I think we can assume that it is in correctly.

tednet,

Are you also using the layout from gaussmarkov's website?

Can you post your voltages?

I will try to get working on mine this week and maybe I will have some voltages to post by next weekend.

zeeman

[gez]

Is the chip the right way round?

Without looking at the pinout of the IC, I would assume that if it was in backwards, it would start to smoke. Since dfeweer does not say his IC is getting hot, I think we can assume that it is in correctly.

I did look at the pinout before posting my comment. If it's in backwards then there's no -ve supply connection to the chip: pin 16, which has no connection, gets wired to ground.  The V+ rail now gets connected to the input of one of the inverters: pin9.  As the inputs have diode protection, I'm guessing that this connection is pulling everything else up to V+ through one of the said diodes (everything is connected internally, one way or another).  Either way, with no direct -ve power connection to the chip, there wouldn't be any fireworks when powered up.

So, given the readings, the chip being in the wrong way round seems the most likely candidate (assuming that the layout is correct).  Perhaps we'll never know - to the OP: wake up man! 

[tednet]

hey guys i was able to fix it. It turned out to be a floppy solder joint. Good thing I used an audio probe to trace it Take my advice, don't do effects in the late night and expect them to be working perfectly , do them during the day and never be tired when doing them

[MikeH]

1)I does pass some signal, but the signal is relatively weak and sounds kind of raspy. I should also ad that the decay of the notes is strange. When I hit a note I get some overdriven sound, but as the note decays, it starts to get kind of farty sounding then it abruptly fizzles away.

This can happen if you used a buffered 4049- make sure you're using the "UBE" version of the chip; ie- CD4049UBE.

[MikeH]

And where did this come from?  I don't see it on the list of articles and schematics at ROG...

[tednet]

it's from some contest, so they probably don't want to make it public public. I suppose there are some other hidden ones too 

[dfeweer]

Is the chip the right way round?

LOL, Give me some credit.

Yes it is in correctly.

... to the OP: wake up man! 

Hey, I'm awake. I had to spend the good part of the weekend with the honey bunny since it was Valentine's weekend.

This can happen if you used a buffered 4049- make sure you're using the "UBE" version of the chip; ie- CD4049UBE.

Never throght of that. I'm almost 100% sure that it is a "UBE".

I am not at home right now, but I will check that tonight when I get home.

Thanks for all the help.

dfe

[gez]

Yes it is in correctly.

OK, is it socketed?  If so, pull the chip and check for continuity between the metal of the socket that comes into contact with pin 8 (the -ve power connection) and ground. 

If soldered, re-flow pin 8's joint.

LOL, Give me some credit.

It has nothing to do with credit - you should see some of the dumb mistakes I make (happens to all of us).

[earthtonesaudio]

It has nothing to do with credit - you should see some of the dumb mistakes I make (happens to all of us).

So true.  The moment you start thinking you're too clever to put a chip in backwards marks the beginning of a long debugging session.   

[dfeweer]

LOL, Give me some credit.

It has nothing to do with credit - you should see some of the dumb mistakes I make (happens to all of us).

It has nothing to do with credit - you should see some of the dumb mistakes I make (happens to all of us).

So true.  The moment you start thinking you're too clever to put a chip in backwards marks the beginning of a long debugging session.   

I hear what you guys are saying, but before I powered up I double/triple/quadruple checked to see if I had wired my power correctly (i.e. +9V to power on PCB and ground to ground on PCB) and I double/triple/quadruple checked to see if I had the IC in correctly.

When things were not working, the first thing I checked (again) was to see if I had the chip in correctly (and then I re-checked the resistors, capacitors, etc.)

This can happen if you used a buffered 4049- make sure you're using the "UBE" version of the chip; ie- CD4049UBE.

I checked the IC. The markings are a little faded but with a magnifying glass, some light, and getting the IC into the right angle, I was able to verify that I do have a "UBE" version of the IC.

OK, is it socketed?  If so, pull the chip and check for continuity between the metal of the socket that comes into contact with pin 8 (the -ve power connection) and ground. 

If soldered, re-flow pin 8's joint.

Yes, it is socketed.

I measured the resistance between pin #8 and ground and my meter says 0.2 ohms.

By the way, as I mentioned in the original post, I checked all of my solder connections and they do look good.

However, there is a lot of flux so maybe there is something I am not seeing due to all of the flux.

On one of my first projects, I used 99% rubbing alcohol to remove the flux (I read that in another thread). But the mixture of alcohol and flux left this white residue around the solder joints.

Can anyone recommend a good way to remove the flux that will not leave a residue?

Thanks again for all the help.

dfe

[B Tremblay]

And where did this come from?  I don't see it on the list of articles and schematics at ROG...

it's from some contest, so they probably don't want to make it public public. I suppose there are some other hidden ones too 

It was from an FX-X contest that had logic chips as the theme.  We are planning to release it as a full project with the usual perf/PCB layouts and sound clips.

And yes, there certainly are other hidden projects!    But they are often revealed eventually.

[gez]

Yes, it is socketed.

I measured the resistance between pin #8 and ground and my meter says 0.2 ohms.

Between battery ground and the metal of the socket? (probe shouldn't touch any solder)

[StereoKills]

However, there is a lot of flux so maybe there is something I am not seeing due to all of the flux.

On one of my first projects, I used 99% rubbing alcohol to remove the flux (I read that in another thread). But the mixture of alcohol and flux left this white residue around the solder joints.

Can anyone recommend a good way to remove the flux that will not leave a residue?

In my experience, leftover flux can cause problems sometimes. I used regular flux a few times and the only way I know to clean it off is with isopropal alcohol and I used a cotton swab. Now I use water soluble flux and just run the the finished board under warm tap water while rubbing with a semi stiff brush. Makes for a much cleaner board.

[MikeH]

My guess would be a solder bridge somewhere.  90% of the time that's whats wrong with my builds.  It's kind of tedious, but I check this by printing out a reverse of the pcb layout I used, and then verifying the shape/path of every trace, highlighting them as I go.  Actually, this ones small enough that it won't be so bad (I had to do it with my sans amp clone!  WHAT A PAIN IN THE ASS).

And you can use acetone and an old tooth brush to remove the flux; it will definitely make the traces easier to see.

[zeeman]

I will try to get working on mine this week and maybe I will have some voltages to post by next weekend.

OK, I have been slacking. 

Last weekend I put the resistors in but I did not get any farther.

I plan to put some more work in this weekend.

I will post voltages as soon as I have the board populated with the rest.

zeeman