ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

How to connect pots and inputs/outputs


 
5/30/1999 2:25 PM
Terry
email
How to connect pots and inputs/outputs
I am new to DIY effects and i recently made en Electra Distortion unit, with not too much problems adn i plan on adding some mods to it soon...  
 
I am currently working on a swell device off of Justin Philpott's site, but i can't figure out where to connect the pots , in/out puts.  
I couldn't get all of the right resistors exactly so i put some resistors in series to add up to the amount needed, which i did on my last pedal. Also, does it matter if i use polarized or non polarized caps, the schemtaics says polarized but i used non, is this why hte cicuit is dead?  
 
 
_thanx
 
5/30/1999 7:22 PM
John C.
email

I'm not such a newby, but I remain as an almost complete ignorant due to my lack of constance and inmotivation to learn :)  
 
But you could look at  
 
http://www.geocities.com/BourbonStreet/Delta/2133/stompbox  
 
it helped me a lot.  
 
And as far as I know, electrolitic(polarized) caps placed in certain places may not be replaced with non polarized, mainly those dealing with both positive and negative "lines" (I believe..)  
 
About the pots, just solder a cable that goes from point 1, 2, 3 on the board, to lug 1, 2, 3 in the pot.
 
5/31/1999 5:19 AM
Michael Burgundy
Website
email

certain places may not be replaced with non polarized,  
mainly those dealing with both positive and negative "lines"  
(I believe..)>  
 
Actaully it´s the other way around. Electrolytics can have high values in compact size at a low price, so theyre often used in powersupplies for filtering out any ripple (all those caps after diode-bridges, right?)  
They are sometimes used in signal paths, BUT; and here´s what polarized means; they only work one way. The + needs to go to one end, the - to the other. Swap them and the cap doesn´t work the way it should, and may get killed in the action (take care to NOT EVER do this in high-voltage supplies (such as tubeamp B+) ´cause the cap will most probably literally BLOW, scattering bits ´n pieces ´battery acid all over the place).  
So, since a non-polarized cap will work in both directions, you can use it (same value) as a replacement for a polarized one, not the other way around. The reason not all caps are non-polarized is economics; price and size vs. value.  
About pots; the middle lug is the wiper (the arrow on the schem/volume control; this goes to output) the lug on the clockwise side (topview) is "on" (volume control; this goes to signal) and the CCW one is "off" (volume control; this goes to mass)  
If you´re not sure as to where to place the outer two ones, just wire it in, see if you get the response you thought you would, and if not, swap them.  
 
Hope it helps.
 
5/31/1999 3:48 PM
Terry
email

I am also building a dod envilope filter 440 which requires some polarized caps, would it work the same if i just used non-polarized?
 
5/31/1999 7:36 PM
R.G.
Website
email

Yes, if you can find them in the right values and it will all fit mechanically.
 
6/1/1999 10:18 AM
Terry
email

I have found most of them at the right values though some i will have to put in parallel to add up the values, will non-polarized still work ok?
 
6/1/1999 10:58 AM
Mark Hammer
email

Yes. Normally, when capacitors are in the signal path, polarity is not an issue. It is simply a coincidence that high value capacitors are difficult to make as small as polarized caps of the same value. (This is partly why you need to put them in parallel to get the required value.) Many folks, yourself included, have understandably interpreted this coincidence to mean that polarized caps are *required*, when they aren't.  
 
Please note, however, that this same laissez-faire approach to caps is NOT called for when we are talking about power lines and power conditioning/filtering (battery or wall AC). There, polarized caps ARE called for, and their orientation matters.  
 
In some cases, some folks might suggest a polarized cap over a non-polarized of the same value, because of the signal-colouring properties of the material used in one type of cap over the other. For example, the polarized 0.22uf tantalum caps used in the Tube Screamer are easily substituted for with a non-polarized polystyrene or even ceramic 0.22 cap, without sacrificing too much in terms of size. For whatever reasons, though, some folks prefer the tantalum.
 
   Page 1 of 2 Next> Last Page>>