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previous: Blues Lyne I replaced all of the treble caps, ... -- 10/21/1999 8:32 PM View Thread

Re: Ceramics or Silver Micas, or both?

10/22/1999 3:23 AM
Steve A.Re: Ceramics or Silver Micas, or both?
to Blues, Jim, Mook and Bjorn:  
    I just tried an interesting experiment with a boost circuit (to remain nameless!) that basically ran the full signal through a 330pF treble cap. One position of the switch used a mica cap and the other used a ceramic cap. With that setup you could really hear the difference between the two types of caps. With the mica cap there was a lot of the lower frequencies coming through which produced a fuller stronger sound. With the ceramic cap the low freqs were practically gone and the overall sound was a bit grainy.  
    The problems with the mica caps mentioned by Gil in the earlier threads was that in the high-gain amp design he was working with, the mica caps allowed too much of the low freqs through which caused subsequent stages to "fart out". Switching over to ceramic caps was a "quick'n'dirty" way to filter out those low freqs that were causing the problems in the high gain stages, and was perhaps the best solution in that particular design (since more complicated ways to cut the bass might otherwise compromise the sound).  
    While we all have our own personal tastes, I do think that most of us agree that a "farty bass" is not a desirable quality in the amps we build or modify. But in other instances where I have installed A/B switches to select between ceramic and mica caps, it is hard for me to decide which sound I like better... so I leave the switch in unless a later mod makes it so that I am always using just one cap or the other.  
    Like an artist painting a picture, having both ceramic and mica caps in our "tonal pallet" gives us more colors to choose from... [end of soap box rant]  
Steve Ahola

Randall Aiken Nice test, Steve!Ju... -- 10/22/1999 6:06 AM
Gil Ayan Steve, a minor clarification: with ... -- 10/22/1999 7:37 AM
Gus remember ceramics are piezoelectric... -- 10/22/1999 2:31 PM
Bjorn Thanx for your answers. I understan... -- 10/22/1999 5:02 PM
Bunky Polystrene, let's not overlook... -- 10/22/1999 9:30 PM