#1
Hey guys I'm looking to do my first mod on a pedal and I have a new Small Stone that is plagued with the volume drop problem but I love the sound of it. So I found this on generalguitargadgets.com : http://www.generalguitargadgets.com/bom/smallvlp.txt

I'm just wondering if anyone has done this and if you could give me some tips on how to really do it and if it's worth it to do myself (ie. easy enough, cheap enough, etc.) and any other information or tips would be great too.

#2
Quote by RG Keen(GGG)
The loss of volume when engaged is correctable in the Issue J Small Stone
by changing the gain of the two-transistor preamp at the input of the circuit.

There are two 4.7K resistors at the emitters of the input transistors. One
(R7) goes to ground from the emitter of Q1, the second (R42) connects the
emitter of Q2 to the emitter of Q1. Those two resistors set the feedback gain
of the two-transistor compound.

Increase the 4.7K between the emitters (R42) to increase the gain. Start with
10K. Be aware that this will affect the stage biasing, so the headroom may
be affected; I don't think this will really be a problem


Steps:

1-Buy parts...Use www.smallbearelec.com because it supports DIY effects.

2-Find the transistor pinout, it commonly goes EBC with the flat side facing you.

3-Find the resistors. Use http://www.dannyg.com/examples/res2/resistor.htm for color codes.

4-Desolder with a soldering braid or so, and take out the resistors.

5-Replace them as it says.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#3
Ok thanks. And also, the site mentions that you have to adjust the resistance. Does this mean that I just have to buy a bunch of different resistors to see which one works? Or is there a way to like tweak around one resistor to make the volume the same. Any words of caution for me while doing this also? Thanks again I appreciate the help.

#4
Well, trial and error will work. You could try and put in a trimpot too.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#5
So I just increase the R11 to 10k and then the R47 also to 10k using trimpots and it should be ok?
#6
Just use 10 k trimpots yeah, and then you can adjust them to however it sounds good
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#7
Ok thanks. Cos towards the beginning of those instructions, the guy mentions the R7 resistor so I wasn't sure if I needed to do anything with that but the recommended part chagnes say to do what I'm going to do so it should work out. Thanks for all the help man.

#8
Yeah, I think you should just replace the R42 with a small trimpot.

Do you have a digital camera? If you do, I'd really appreciate it if you could submit the mods to http://www.stompboxmods.com/

Thanks
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#9
Yeah I'll try but I just realized that my circuit board looks a lot different from the schematic on that site and I think I have a different pedal. I bought it off eBay so I don't know the year it was made but I think it's a newer one and the circuit board is definitely different. Will this mod still work?
#10
The shematic isn't the same as the PCB layout. And I think the PCB layout on that site is different, so they don't have copyright issues. Should still work.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#12
Ok so I got some trimpots and they three prongs on them so what do I do with the third prong in the middle? Or did I get the wrong trimpots? Help please!