Small Clone Help Please

Started by Barcode80, May 28, 2008, 02:28:55 AM

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Barcode80

I've searched the forum and the net both extensively. I have an older small clone and i want to true bypass it. all the posts i've seen on this topic don't really address how to do it. i know the current from switching on the LED flips a fet that introduces the delayed signal into the mix. i was wondering if i could just replace the LEd with a 1n4001 hard wired from what would normally be the current limiting resistor to the fet connection, so that the fet is always on. then true bypass from input and output. but it seems to easy :)

so how the frick do you bypass this sucker?

analogmike

you could do that, but easier to yank the FET and put a jumper in, as if the FET was always on.
DIY has unpleasant realities, such as that an operating soldering iron has two ends differing markedly in the degree of comfort with which they can be grasped. - J. Smith

mike  ~^v^~ aNaLoG.MaN ~^v^~   vintage guitar effects

http://www.analogman.com

SonicVI

To elaborate on what Mike said, just solder a jumper between the outside pins of the FET. This will make the pedal "always on". Then find the input and output wires to run to the new switch. For the LED just tap the 9V from the pcb where the adapter jack/battery connects.

Barcode80

nice. thanks for all the help, i'll give it a try and if it works out, i'll make a tutorial. i saw a lot of questions on this one but these are the first real answers!

Barcode80

okay, i took pics, and i need you guys to help me with whether i have the labels right. The only fet i can find on the board is a tin can 2n4340, so i assume that is the switching fet that needs to be bridged. as for the wiring, i'm pretty positive on it, but let me know if i've missed anything.



Barcode80

bump. seriously need help guys. i removed the only fet i could find on the board, the one marked "switching fet" on the above pic. i then jumpered the outside fet legs. then, i wired a dpdt wth the effect in and out wired to the points labelled on the board and then the jacks wired to the poles, normal dpdt fashion. now i get no chorus switched on or off. have i jumpered the wrong fet legs?

Barcode80

#6
SUCCESS!!!!

Okay, here goes.

Above images have marked on them the wires you will be moving, which will be the effect in, the effect out, and both wires from the LED.

You will want to desolder both ends of the LED and probably toss it. that one sucks anyway :)

remove the wires attached to the tip connection on each jack. attach the one that was going to your output jack to the top right lug (if facing the lugs on the bottom of the switch like below) and the one from input goes to the top left lug:

EFFECT INPUT _   _   _  EFFECT OUTPUT

INPUT JACK     _   _   _  OUTPUT JACK

                      _   _   _
                      |_____|

The middle lug between effect input and effect output connections will be soldered to the negative LED leg. the dead center lug goes to ground.

Then find the metal can (at least it is a metal can on my version) JFET that performs the switching, as marked in the image above. carefully remove the fet (in case you ever want to restore the old switching) with a heatsink attached to it. then, bridge the two legs of the JFET that are on the outside of the board. that would be the center leg and the one farthest to the outer edge of the board. tidy up the wires, and fire it up! you should now have a nice true bypass small clone.

NOTE: you will also have to desolder the pot and pull it out as far as it will go and still solder in place in order to let the board free up room for the new switch.