Help needed with wiring Small Stone Issue J for True Bypass
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Posted: 10 March 2009 06:36 PM

Hi there,
I could need some help with the proper wiring of a 3pdt switch for my small stone. It’s an “issue J” and I wired the switch like this:

Lug 1 - Pole 1 No Connection -  Pole 2 Jumper to Pole 3    
Lug 2 - Pole 1   to Ground - Pole 2 to Input Jack - Pole 3 to Output Jack
Lug 3 - Pole 1   to Led + - Pole 2 to Board Input - Pole 3 to Board Output (If I recall it right, might be just the other way round…)

Well, it works, but in bypass with the color switch in the up position the oscillation is even worse than before…it sounds very much like a bird. From the pictures of the reissue small stone with a 3pdt switch I can see that a different wiring is used. How does it work?

Any information would be really appreciated!
wink

thanks, michael

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Posted: 11 March 2009 07:16 AM | Link to this reply (#1)

Small Stone don’t take very well to true-bypass, at least the vintage units don’t.

Ron Neely II
The EH Man, All-Knowing Guru of Electro-Harmonix
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com

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Posted: 11 March 2009 04:24 PM | Link to this reply (#2)

I TB’d my vintage unit just fine, you need to ground the effect input or it will oscillate in bypass mode.

Just run a wire from effect input, not the in jack, but the effect in to ground, it will fix your problem.

If you only have a DPDT re wire it like the DPDT switch in this diagram, the one on the bottom left corner.

http://i119.photobucket.com/albums/o127/truthandshame/Big Muff/CCCPBIGMUFFTBD.jpg

Edited: 11 March 2009 04:29 PM by Liberty Belle
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Posted: 13 March 2009 07:42 AM | Link to this reply (#3)

@ Ned Flanders: Thanks a lot! Works great now!

Cheers, Michael

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Posted: 07 July 2009 08:13 AM | Link to this reply (#4)

I’ve got this oscillation in bypass problem too.
Putting a dpdt switch on my 1979 Small Stone made
the oscillation problem worse. I didn’t quite
understand Ned’s description above. Can someone
please show on a picture where I should solder the
wire to “effect in” and “ground”.

BR Thomas from Sweden

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Posted: 07 July 2009 04:40 PM | Link to this reply (#5)
madelephant - 13 March 2009 12:42 PM

@ Ned Flanders: Thanks a lot! Works great now!

Cheers, Michael

Cool.


@the above post, you just have to wire it like the guy above you did and it wont oscillate in bypass mode.

Can you locate the effect input and output wires?

Edited: 07 July 2009 07:07 PM by Liberty Belle
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Posted: 11 July 2009 06:18 PM | Link to this reply (#6)

@the above post, you just have to wire it like the guy above you did and it wont oscillate in bypass mode.
Can you locate the effect input and output wires?

I’d appreciate if someone can upload a pic with description on where to solder the wire ends.

Also, when in color mode on, when I engage the switch there’s a loud pop. Can I expect this to dissapear when I ground the effect in? There’s no pop when in color mode off.

BR Thomas

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Posted: 11 July 2009 06:43 PM | Link to this reply (#7)

Hey, as I understand it, there are differences regarding the layout of parts in the different issues of the small stone…the main thing is, you have to identify the “effect input” like ned flanders wrote: not on the input jack, but the input on the circuit board (the spot where the signal is fed to the phaser) - then you run a wire to ground.  You should already have figured that one out, because the true bypass wouldn’t work otherwise. On a website called general guitar gadgets you will find a description of the wires. If I recall it correctly mine were different. But after a little bit of trial and error I found a way it worked. I dont have a digital camera, but I see if I can borrow one. You should see a gutshot of my small stone by the end of the week. But it looks rather messy - I would make a really gruesome surgeon.
:D


Cheers, Michael

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Posted: 11 July 2009 07:22 PM | Link to this reply (#8)
madelephant - 11 July 2009 11:43 PM

Hey, as I understand it, there are differences regarding the layout of parts in the different issues of the small stone…the main thing is, you have to identify the “effect input” like ned flanders wrote: not on the input jack, but the input on the circuit board (the spot where the signal is fed to the phaser) - then you run a wire to ground. 

Cheers, Michael

No you don’t, you wire the switch so when its in bypass mode the input of the circuit is switched to ground. If you just wire the circuit to ground it wont work,ever.

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Posted: 12 July 2009 05:04 PM | Link to this reply (#9)

I opened my Small Stone and took a picture.
To make sure I understand, can someone please
guide me and show on the attached picture where
to solder.

BR Thomas

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smstone.jpg
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Posted: 12 July 2009 05:31 PM | Link to this reply (#10)

Perhaps you’re refering to the lower
true bypass alternative on the attached
picture in this post?

BR Thomas

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dpdt.gif
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Posted: 13 July 2009 02:29 PM | Link to this reply (#11)

The second/lower of the true-buypass pictures is exactly the one you need to follow: Notice how it connects the circuit board input to ground when the circuit is bypassed.

On the picture of your smallstone guts, the circuitboard input is just off-centre of the board and currently connected by the black wire to the bottom left lug on the footswitch. This gives you true bypass switching, but without the input being grounded (i.e. it’s the same as the TOP picture of the two true-bypass schematics you posted). Just rearrange the connections so it ressembles the second picture. The white wire that emerges from the circuit board immediately next to the input wire and connects to the lug opposite the black input wire is the effect output. The red wire on the switch is the pedal input, and the white wire opposite that on the switch is the pedal output.

Hope this helps…

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Posted: 14 July 2009 01:01 PM | Link to this reply (#12)

Ok, I see it clearly now. Thank you all!

One question remains. The wire going from
switch to ground: One end is soldered to
switch and the other end is soldered to what?
Where is the best “ground spot” to solder to?

BR Thomas

Edited: 16 July 2009 06:41 AM by user2883
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Posted: 23 July 2009 05:52 AM | Link to this reply (#13)

I just got a used Sovtek/Russian Smallstone. One of the newer ones in the smaller black box with just four screws on the top.

It doesn’t work. It lights up and passes a signal. The color switch even engages (you can hear a filter change). But there is no phase and the rate knob does nothing.

I am thinking it might be a ground problem. Inside all looks OK except there is a white ground wire that is not attached to anything. One end has a small washer to screw it down somewhere, the other end was soldered to something but now it is just flopping around loose.

I don’t want tru-bypass, just want it working again.

Can anyone tell me where this ground wire attaches?

(Not sure if this deserves a new thread. Am I hijacker?)

Edited: 23 July 2009 05:57 AM by fikus
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Posted: 23 July 2009 12:58 PM | Link to this reply (#14)

I found great guts photos of the latest Sovtek Smallstone here: http://www.pedalarea.com/small_stone.htm

The white ground wire seems redundant as the input jack is grounded to the casing with a washer, but I connected it anyway and still no phasing.

Edited: 24 July 2009 05:14 AM by fikus
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Posted: 23 July 2009 04:30 PM | Link to this reply (#15)

The white wire has nothing to do with it.  I’d suspect a bad CA3094 IC.  There are 2 that produce the oscillating signal.  When one goes bad, no phasing occurs but it will still pass signal.

Ron Neely II
The EH Man, All-Knowing Guru of Electro-Harmonix
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com

EHX Customer service: http://newsensor.com/CutomerServices.aspx
Questions about power supplies w/ EHX products?: http://www.ehx.com/forums/viewthread/2957/
EHX power supply info and requirements: https://spreadsheets.google.com/ccc?key=0Ak9R7oW8W8MidHhCOHdKSkFTdGowdklDd2sza2VXMFE&hl=en&authkey=CJXI1aEF

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