Author Topic: Which Ampeg Scrambler schematic is correct ???  (Read 3153 times)

trescat

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Which Ampeg Scrambler schematic is correct ???
« on: September 12, 2004, 12:26:24 AM »
I have checked four different ampeg Scrambler schematics which are available on the internet, and two of them are different than the other two, one of them is the original schematic, which shows the 1uF electrolytic cap which comes off Q1 as having the negative polarity connected to Q1's emitter Here is a couple of links to that particular schematic --
http://members.aol.com/portaflex/schems/scrambler.gif http://http://members.optusnet.com.au/trescat/pictures/scrambler%20original%20Sch.gif
The schematic at tonepad shows the same arrangement --
http://www.tonepad.com/getFile.asp?id=31 http://But the schematics at General Guitar Gadgets ---http://www.generalguitargadgets.com/diagrams/scrambler_sc.gif
and the one at Fuzz Central ---
http://fuzzcentral.tripod.com/scrambler.html [url]
Well they both have this particular Capacitor with the polarity reversed from the original schematic, so which one would be correct, I am assuming that the original would be the way its meant to be , but then why would they change the arrangement at those other two sites, any light on the matter would be appreciated.

Cheers
Trevor :)

Tychobrahe1979

Which Ampeg Scrambler schematic is correct ???
« Reply #1 on: September 12, 2004, 04:35:15 PM »
I built the one from GGG and it worked perfectly the first time I powered it up.

phillip

Which Ampeg Scrambler schematic is correct ???
« Reply #2 on: September 12, 2004, 04:52:54 PM »
The original factory schematic is in error.  The 1uF capacitor attached to the emitter of Q1 should have its positive side connected to the emiiter, just like the 5uF that's also attached to the emitter.

If you wire it so that the 1uF is as shown in the factory schematic, the capacitor will be in reverse polarity and it will dump about 0.5V onto the output and then onto the switch, making a horrible POP when it's switched on and off.

Phillip

trescat

  • Guest
Which Ampeg Scrambler schematic is correct ???
« Reply #3 on: September 12, 2004, 05:18:35 PM »
Thanks Phil.