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previous: Greg O'Connor Preamp -- 4/4/1998 7:43 PM View Thread

Re: O'Connor Preamp (solved)

4/14/1998 11:11 AM
GregRe: O'Connor Preamp (solved)
Well, I figured it out, for what it's worth.  
The preamp diagram in the book shows wiring to be used w/ the book's "Experimenter's Power Supply" which has a DC filament supply. Basically, has one 6.3vdc wire to pin 9 and the other to ground w/ pins 4 & 5 connected to ground. Well, I wired mine exactly the same way except that I'm using an AC filament supply. Plus, I had the filaments referenced to grnd w/ two 100R resistors. So, essentially, one side of my filament supply went to the 100r res to grnd and on to pin 9. While, the other side went to a 100r res to grnd and on to grnd again. Doh!  
Solution: Ran directly to pins 4 & 5 and disconnected the pin 4 & 5 connection to ground as per the DC version.  
Anyway, it sounds good but I do have a question. I don't have a seperate power amp so I'm just running into the front end of my regular amp and I can't turn the preamps volumes up very much at all before it's just too loud. And this is w/ my amp's volume low (about 2 or so). I have to keep the preamps volume barely on. That seems a little odd to me.  
Also, it's a little bright sounding on the distortion channel. Clean side is pretty nice.  
Any thoughts...  

Doc Greg:Sounds like you're run... -- 4/15/1998 7:41 AM
Jack Orman Time to build that DiY Champ to go ... -- 4/16/1998 9:40 AM