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previous: Peter S The coloration inherent in guitar a... -- 6/5/2000 4:25 AM View Thread

Re: Mod Removal Request

6/6/2000 1:51 AM
Steve Ahola
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Re: Mod Removal Request
Peter:  
 
It's the circuitry!  
 
    Well, a nomimal 70uF PS cap reading around 110uF can make an amp sound darker than if you were to replace it with a modern 70uF or 80uF cap. I would agree with you if you were to define "circuitry" as being the actual values measured for an particular amp specimen. Even if the parts are within the rated 20% tolerance that can make a very big difference in the sound...  
 
    Jim's suggestion about using the Sprague/SBE PS coupling/tone caps as replacements for an amp from the 60's is right on because I believe that they are very similar to the good caps used back then (like the blue tubular ones).  
 
    As for the never-ending debate between types of coupling caps, I recommend the following experiment: for one of the more critical coupling caps wire up a switch so that you can select between different types (ceramic, mica, polyester, polypropylene). The difference can be most noticeable if the signal is very rich with lots of harmonic content. Or not... if there is a lot of compression and high freq roll-off after that point in the circuit you might not hear that much difference. With something like a 470k/470pF RC "couplet" after a distorted stage I could really hear the difference between a ceramic and a mica cap- like night and day.  
 
    I suggest that the different brands and styles of caps be used as an artist used colors on his pallet— in some applications you might want the characteristics of one type of cap...  
 
--Thanks!  
 
Steve Ahola

 
Replies:
Peter S Steve, Yes that's exactly ... -- 6/7/2000 1:51 AM