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Fetzer Ruby problem

Started by XinTX, August 04, 2007, 12:22:02 PM

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XinTX

Just worked up a Ruby with the 'Fetzer Valve' mode from ROG.  But now I can't get it to work at all.  All I get is a hum.  If I turn the volume pot down all I get is a motorboat noise.  I've retraced the components against the schematic and don't find anything wrong.  Any ideas where I should look? 

tonyharker

Did you just put the Fetzer valve circuit in front of the Ruby circuit or did you replace the Ruby FET with the Fetzer FET?

XinTX

It's the circuit on the ROG FAQ page as shown here:


tonyharker

I have a few further questions for you:

have you any photos of your construction you can show us?
What did you build the circuit on - PCB or Perfboard?
What is your supply, battery or ???   If you are using a battery is it a good one?
What FET did you use and are you sure it is the right way round? 
What source are you using - a Guitar?
Have you tried feeding the input directly into the top of the volume control?
Have you adjusted the drain of the FET to 4.5 volts?

Sorry about the Qs but it is necessary to find out exactly what you are doing.

Tony.

XinTX

Quote from: tonyharker on August 05, 2007, 03:06:41 PM
I have a few further questions for you:

have you any photos of your construction you can show us?
I could, but my camera takes photos that are too large to host.  I'll try to figure something out.
Quote from: tonyharker on August 05, 2007, 03:06:41 PM
What did you build the circuit on - PCB or Perfboard?
Perfoboard. 
Quote from: tonyharker on August 05, 2007, 03:06:41 PMWhat is your supply, battery or ???   If you are using a battery is it a good one?
Battery.  Tried more than one.  All read 8.6V or better.

Quote from: tonyharker on August 05, 2007, 03:06:41 PMWhat FET did you use and are you sure it is the right way round? 
J201.  Yes, I'm sure it's right way round.

Quote from: tonyharker on August 05, 2007, 03:06:41 PMWhat source are you using - a Guitar?
Yes, a guitar.

Quote from: tonyharker on August 05, 2007, 03:06:41 PMHave you tried feeding the input directly into the top of the volume control?
No, haven't tried that.

Quote from: tonyharker on August 05, 2007, 03:06:41 PMHave you adjusted the drain of the FET to 4.5 volts?
No.  I'll measure and see what I have.  My resistance values aren't jiving with what I think they should be.  I think I may have the variable resistor in wrong. 

Quote from: tonyharker on August 05, 2007, 03:06:41 PMSorry about the Qs but it is necessary to find out exactly what you are doing.

Tony.

joecool85

Quote from: XinTX on August 05, 2007, 06:39:55 PM
I could, but my camera takes photos that are too large to host.  I'll try to figure something out.

Do you know how to use any photo editting software?  You can open up your image and then "save for web" and it will compress the image for you so it takes up less space.  Also, trim it down to 600x450 pixels.  If that sounded like german to you, you can email me the pics and I'll do it for you so we can see what your project looks like.

If it did make sense but you don't have software, you can get free photo editing software like The Gimp:  http://www.gimp.org/downloads/

If you scroll about 1/3 of the way down you can download The Gimp for Unix, Windows and Mac OS X.
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