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Lava Rim 2 questions


 
9/13/2000 2:06 AM
Distortionfreak
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Lava Rim 2 questions
I built a lava rim 2 a couple of weeks ago, and I just finished putting it in a hammond box tonight (I'm so lazy). I used a .22uf cap at the input, and 2N3904 transistors. Actually I used all Radio Shack parts. 1 problem is that when I put the drive all the way up, I get this high pitched squeal noise (not feedback) any ideas? (I know I asked this question before). Also would the bias pot(which I didn't use) at the input serve as a level or master volume? I noticed that I could get some cool sounds by adjusting the drive and the volume controls, but the level wasn't right. Thanks
 
9/15/2000 12:31 AM
aron
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>1 problem is that when I put the drive all the way up, I get this high pitched squeal noise (not feedback) any ideas?  
 
This is usually due to the input and output wires being too close to each other or some sort of layout problem.  
 
>Also would the bias pot(which I didn't use) at the input serve as a level or master volume?  
 
Not really, it lowers the signal hitting the pedal - same as if you had just turned your volume down on the guitar. The volume pot (last one in the signal chain) is the one that controls the output level.
 
9/15/2000 11:16 AM
Distortionfreak
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I tried moving the wires apart, still same problem. The layout is prety much the same as yours, according to the picture you have posted. Someone suggested a small cap about 25pf from input to ground. What do you think? Thanks for your help
 
9/15/2000 5:45 PM
aron
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Are the wires fairly short as well?  
 
What transistors are you using in there?  
 
You can try the small cap from input to ground as well.  
 
Aron
 
9/15/2000 6:37 PM
Distortionfreak
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The wires are actually probably a bit long.How short should they be? I will cut them as I have now put it in a box. I used 2N3904's and 1n4001 diodes. Could it be a bad pot? I used a Radio shack pot. It's only when it's all the way up. It's still not as bassy as I would like, so I think I'm going to change the input cap( I used a .22uf). I think once I get these things straightened out, this pedal has potential to be one of my faves. Thanks again
 
9/15/2000 7:47 PM
aron
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Well, you basically want them as short as possible and have the input and output wires as far apart as possible. If they intersect, make them intersect like at right angles.  
 
Another tip is to try running them along the edge of the box as well.  
 
Which pot has the problem, drive or level?  
 
>so I think I'm going to change the input cap( I used a .22uf).  
 
You can try playing around with the .22uF as well after the transistors - try putting in a 1uF electro - positive side towards the transistors.  
 
I have fun with this pedal - swapping transistors in and out and tweaking the trims. It is a fun pedal.  
 
Good Luck!
 
9/15/2000 8:00 PM
Distortionfreak
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It is the drive pot.  
I put it in a Hammond 1590bb box, which I painted blue to match my strat. I mounted the jacks on opposite sides. I will go in there tonite and shorten the wires,to see if that helps.  
Should that cap be electrolytic? I used a film cap.  
Can I mix npn and pnp transistors in this pedal?
 
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