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Re: Shaka HV


 
8/22/2000 11:35 AM
Bud
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Re: Shaka HV
so when Jack was promoting higher power supplies he was herding us in the right direction?  
 
by 100k or 500k pot, I guess you mean the drive pot on the opamp?  
 
are you endangering the opamp by powering it with 36v?  
 
Bud
 
8/22/2000 5:34 PM
aron
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Yes, the drive pot on the op amp.  
 
Hmmm.... I did not check the voltage limits on the op amp :-)  
 
UH OH! I just checked - it should be 15V maximum.  
 
Oh well.... it works....
 
8/22/2000 6:12 PM
Petri Junno
> Hmmm.... I did not check the voltage limits on the op amp :-)  
> UH OH! I just checked - it should be 15V maximum.  
 
 
Thats probably +15 volts to the positive suply pin and -15 to the negative suply pin so the difference between positive and negative suply pins can be 30v. When you use opamps with sinle suply the biasing makes the inputs sit in 1/2 V+ and to the opamp it looks like it has 1/2 of your V+ in the positive suply pin (36V/2=18V in this case) and -1/2 of your V+ in the negative suply pin (-36/2=-18V in this case). Doesn't look that bad anymore? It's over the ratings anyway but I think there are opams that can handle that...  
 
This is how I have understood it anyway, when readin opamp specifications...  
 
-Petri
 
8/22/2000 6:24 PM
aron
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Thank you!  
 
That's right!  
 
OK, then I am "only" 3 volts over the max :-) Running dangerously :-)  
 
That means the dreaded Burr Brown chip I have could safely run within these limits - too bad I don't like the way it sounds.  
 
I'm even more confused. I just realized I have a TI RC4558 in there. Why was I looking up a TL072?
 
8/22/2000 6:31 PM
aron
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Re: Shaka HV RC4558 is OK
Hehehe, lucked out!  
 
The RC4558 is rated at 18V for the input.  
 
Perfect!  
 
Aron
 
8/22/2000 11:50 AM
Doug H
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Re: Shaka HV
Maybe it's time to try the mini-tubes again? I got weary of the pwr supply wickey-wackey on that one. Might sound real good with that marshall spkr sim.  
 
Doug
 
8/22/2000 5:36 PM
aron
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What doesn't sound good with that speaker sim??? :-)  
 
Doug,  
 
How do I find an op amp that is designed to handle 36 volts?  
 
Any suggestions?  
 
Aron
 
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