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'1st build-Hi Octane?'
Author:spud (registered user: 3367 posts )
Date: Fri, Mar 14th, 2008 @ 11:28 ( . )

Hey chris,

Changing the cathode bypass caps increases the gain - there is big thread on this that I took my que from, do a search for "more distortion" under the HO area. If I have time later I'll go find it and post again. It pushes each stage a little harder making it dist earlier and more when you max it. I really like it now - like I said I upped stage 2 bypass capped from 1 uf to 1.68 uf (I just soldered a .68 uf cap in parallel with 1 uf cap). I also, put the 1 uf bypass cap that had been taken out of stage 3 (it has no bypass cap in the 06.02.23 version). If you look at the latest draft HO schematic, it's back in (by popular demand I suppose). I've also used .68 uf on stage 1 exactly per the schematic - my kit came with a 1 uf for the first stage but I didn't use it and bought a .68 uf to put in that spot. I used that 1 uf in the 3rd stage when I started to mod the amp.

Keep in mind that if you have electrolytic caps in there now and you want to parrallel the .68 uf to the electro, you have to solder it across the leads. When you do this, you need to protect the electro with some heat sinks - I used those cheap aluminum ones you can get at Radio Shack. I used 2 so they would soak up the heat. I did a similar thing with the stage 3 and paralleled the 1 uf electro cap with the cathode resistor. Looks kind of funny but it works.

I also tried playing with the bright caps but I didn't see a big diff there so I went back to stock. Other people say they like the Mesa or SLO type bright cap configs better - I put them on a 3 pos DPDT switch (up was mesa, mid was stock, down was SLO). I spliced it into the bright caps that are in place and tried them - no big change so I took it back out. You might think different - there is a thread on this, search for "bright cap".

Here is the link to KOTB -


Also Youtube has some KOTB contest vids. I don't plan on entering, I just like some of the backing tracks and their fun to Jam to for practice.



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--* 1st build-Hi Octane?
3/15/2008 @ 22:17--ChrisC

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