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previous: Steve Ahola Re: Weird Report, Steve... Re: humble clone -- 7/12/2000 5:10 AM View Thread

Trip + Presence + Why Dumble's Way?

7/12/2000 5:08 PM
Gil Ayan
Trip + Presence + Why Dumble's Way?
quote:
"Gil:  
 
    Glad to hear that you're back! So how was the trip?"
 
 
Thanks! The trip was fabulous, and the highlight was definitely Spain (I hadn't been there before). It has great beaches, it is fun, cheap, and the food is great. If Tom Jobim were alive and saw me, he would re write his famous song... "Tall and fat and tan.." Yes, I made a living pig out of myself thanks to the Spanish cuisine! Saw some real guitarists out there too, seems like everywhere you go there is a great flamenco player... Maybe the Spaniards think the same about jazz guitarists in the USA, there's one in every crowd.  
 
So, highly recommended -- provided you speak Spanish and don't mind putting on a few pounds. Then, London (it was hard to be reminded how unfortunate some people are from a culinary standpoint :D ) and Paris were great too, but nothing new to either my wife and I... and much more expensive. As for Morocco, it was very different... We went to Tangier only, and I think it'd be like passing judgement on Mexico if you've only been to Tijuana, you know what I mean? Ok, so much for this.  
 
* * *  
Back to the presence control. The cap dumps highs to ground before they are subtarcted from the signal at the NFBL. So, the bigger the cap, the more midrange you "save," and so the thicker the sound of the presence control.  
 
Now, what is different about Dumble's design is that his presence control is roughly scaled by a factor of 10 with respect to Marshall. Thus, the cap is 1uF instead of .1uF, the pot is 2K instead of 22K, etc. While the ratios are pretty much the same, and the NFBL is primarily a voltage arrangement, one could expect similar responses. However, what are, in reality, the differences between the "common practice" and the "scaled down" version of a feedback loop? I have never heard an answer I thought made much sense to me. So, why does he do it that way? I have no idea.  
 
Gil

 
Replies:
Ray Ivers Gil,Sounds like you... -- 7/12/2000 6:10 PM