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Vintage threads from the first ten years

Millenium bypass

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7/20/1999 3:28 PM
JohnC	Millenium bypass Question: Does the R.G.'s Millenium bypass need an specific value for it's resistor noted as "optional"? Any "average" value that would work for, let's say, a: RAT, GeoFex Screamer or A.Nelson's/Jack Orman's Shaka Braddah III...? Does a too low or too high value/resistance affect the sound? thank's. johnc

7/20/1999 4:07 PM
R.G.	As noted, it may well not be needed at all. You can try it without the resistor, as the current is limited by the JFET. If you like belt and suspenders, start with 510 ohms. The resistor has no connection to the audio path in either bypass or effect mode, so it can't have any effect on the sound in any way.

7/20/1999 4:29 PM
Farrow	Depending on the "on" resistance of the FET, the LED may draw too much current. Ever hooked a LED right to a 9V battery? They get real hot and then they go out. The same thing happens with a couple of different kinds of JFETs in the Mil. bypass cct. I never noticed it until I started putting AC adaptor sockets in my pedals. Then I blew a lot of LEDs... I use 1k, it's nice and safe.

7/20/1999 4:43 PM
R.G.	I must be using the wrong or right JFETs, depending on how you look at it. I've never had one get too much current, but it certainly could happen; that's why I put the resistor in, but made it optional. 1K is certainly OK.

7/21/1999 4:04 AM

Ok, thank you very much.

Now I have another one that was going to a different message, but here it goes:

unusual resistor values

I need a 510k resistor, value that's not usual at all around here where I live.

How should I connect a 470k and a 39k resistors to obtain that 510k value?

Is it in serial? (I mean, "one after the other")

Would it work like that?

Thanks again for your help.

n.b.: it is not for the M bypass, but for the GeoFex screamer I'm building righ now.

johnc

7/21/1999 12:18 PM

John:

>I need a 510k resistor, value that's not usual at all

What tolerance resistors do you have? 1%? 5%? A 5% resistor could measure anywhere from 475K to 525K! Even a 1% resistor could be as high as 505K!

>How should I connect a 470k and a 39k resistors to obtain >that 510k value?

When you connect resistors together in series, you add their resistance values. So 470K + 39K = 509K. On the schematic for the Screamer, does it say something like "all resistors 20%?" Anything like that? I think you'd bo OK with 500K.

Farrow

http://surf.to/pharaohamps

7/22/1999 1:36 AM
JohnC	Farrow, R.G.: Thanks for your help! I finally put them in series, and both pairs measured a bit more that 500k, so maybe that's near enough. johnc

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