Screaming Bird does not scream...

[sengo]

Hey everyone,

I just finished building a Screaming Bird/Tree and it sounds pretty cool, but there seem to be some problems with it. It's not out of control treble like I expeced, but thats alright because I really like the tone I am getting from it. My main problem is that when ever I turn the boost on it mutes my playing considerably, which is not good. I did have to swap the 43K resistor for a 33K resistor, because I made a mistake on my small bear order. Could this be the reason it's so muted?

http://fuzzcentral.ssguitar.com/schematics/screamingbirdschem.gif

Any advice would be greatly appreciated. I build the rest of the pedal exactly to the specs given in that link.

Nick

[theehman]

Just put a 10k in series with the 33k to get the correct value.

[sengo]

Ah! I didn't even think of that... wow.

Thanks, trying it now.

Edit: That didn't seem to change much, still very muted.

[foxfire]

not for nothing but did you check that the transistor is in correctly? i'm only suggesting cause i know tend to over look things like the direction of my diodes and silly things like that.

[gez]

I think Rylan is on to something.  These things make your ears hurt (no joke) after a few mins playing.  If you're not screaming in pain and blood isn't pouring out of your ears, something's up...

[foxfire]

it might not hurt to re flow all your joints also?

[ambulancevoice]

what transistor did you use?

[sengo]

I used a 2N5088 transistor. I checked the direction and thought that may be it for an instant, then remembered the layouts are mirrored, so it's in correctly. I've resoldiered most of my joints, Ill do it again. I think I'll swap the tranny around jsut incase both my layout and the other ones ive seen are incorrect. Tranistors always have confused me a bit, magical little black boxes.

edit: I just resoldered some traces, and now my ears are bleeding. I see what you mean, haha.

[gez]

I just resoldered some traces, and now my ears are bleeding. I see what you mean, haha.

Happy headaches!

[sengo]

Heh, Through my old guitar and really old amp it has a nice Link Wray "Rumble" sound. Coupled with my EA Tremolo this should be awesome.

Thanks for the help guys.

Nick

[wbajzek]

Hi, newbie here. Sorry to resurrect this ancient thread, but I just built one of these and had exactly the same result at first; bass filtered out but reduced volume. I checked all my solder joints and even replaced many of the wires and the transistor (I tried a 2n3904 and 2n4401). In the end, I got it working by flipping the transistor around. This really bugs me, because although it's only the 4th device I've made, most have used the same type of transistor and worked properly the first time.

I have quadruple checked the schematic, layout diagram, and the ebc diagram on the package from the transistors, and I'm sure I now have the collector where the emitter should be, and vice versa. Is there anything else I could have done that could have caused this? Everything but the transistor is wired as in the schematic, with the exception of an stomp switch I've added and a TRS jack on the input. I tested each of the components with my multimeter and got the expected readings.

I just went ahead and built this on a piece of cardboard. I think I have enough parts to make another on a breadboard, once I get one, to see if I get the same result.

[wbajzek]

I'm pretty sure now that I did just misinterpret the pin diagram on the package... nevermind.

[Earthscum]

You're not the only one... It took me a long time to get it all straight. Source (fets), and collector are to negative ground, and Drain (fet) and Emitter are to positive rail, but NPN is backwards. It doesn't "Collect" electrons from the neg rail and "Emit" them to the positive rail... Well, it actually does, but you just have to remember that NPN's are basically labelled wrong in the scheme of actual electrical action.

[wbajzek]

Well, the General Guitar Gadgets layout (http://www.generalguitargadgets.com/richardo/perfboard/index.html) shows the transistor reversed from how I have mine, assuming that is a birds-eye view. but the CBE pins are in the same places, regardless of the shape of the transistor, and that's the important thing.

Now I just need to figure out how to make it less noisy and get some holes drilled in my box. I didn't do a particularly clean job of assembling it so I may redo it on a veroboard as in the diagram. I chose this device because it was simple, but it turns out that it pairs well with my Vox AC4TV.

Could the noise (high frequency whine/hiss) have to do with C1 and C2? I used ceramic disc caps for those, but in the layout diagram they appear to be electrolytics.

I am definitely going to build my next iteration on a breadboard because I am curious about the caps, particular if C1 and C2 have to match and why.