Mod

[Deisel401]

Hi everyone. I saw a post for a mod which I did to my SL+. I changed 3 resistors; R1, R2, and R3 from 1/2 watt 470 ohms, to 1/2 watt 150 ohms. According to the post this mod would eliminate some "fizz" and noise. I did a really clean, careful job on this so I'm quite sure I didn't damage anything. But, my SL+ is now a super clean tone with approximately an 1/8th of normal volume. No gain at all. So I'm wondering if I did somehow damage a trace or contact, or if these 3 resistors have a lot to do with gain staging and the instructions in the post may not be totally accurate ( no offense to whomever posted it ). The post indicated that this mod is more for hi-gain modules. I thought the SL+ is considered hi-gain. . . .? Anyone have any ideas? I'm willing to "overnight" an extra turkey leg to them. Hope everyone had a great , safe Thanksgiving. p.s. - i checked the entire pcb with a magnifying glass 2 x and all looks good.

 

[Graham Pearson]

I have 2 SL+ modules. One has the black stripe on silver face plate and has 470 ohm 1/2W resistors in R1, R2, and R3 and the other has an all-black face plate with 150 ohm 1/2W resistors.

Both my modules exhibit about the same amount of gain. So there must be something other than these resistors that is affecting your gain.

 

[Shinozoku]

Did you happen to put one of these resistors in R7 as well? Or remove an electrolytic cap from the middle of the board? A pic would help tremendously.

And a Happy Thanksgiving to you as well!

 

[Deisel401]

Hi guys and thanks for responding. My SL+ has the black stripe on silver face plate. I only changed those 3 resistors; R1 , R2 , and R3. Didn't touch R7 or anything else. Graham you said both of your SL+'s sound the same so I'm guessing this mod was pointless. . . ? Shinozoku I'm working on learning how to get some pics posted. But because I changed ONLY those 3 resistors and nothing else, and these resistors do not affect gain, that means that I probably damaged something on the pcb and didn't realize it. Thanks for helping me track down the prob. Gonna get my soldering gun heated up and grab the magnifying glass again and try to fix this. Thanks again.

 

[ak37]

Check your soldering and you resistor values. The latter can get you quickly! As I get older, :-(, my eyes trick me and the damned color bands look mis colored. Is that red or orange? Once I put a 4.7k in place of a 470 before! That really chokes the signal! LOL

 

[kc2eeb]

I always check my resistors with a good multimeter no matter what they're marked. Once in a while you'll find one that's open, infinite resistance.

 

[Deisel401]

That's def good info. I went back and checked my work and fired it up again. Same prob so idk what the hell i did. I'm gonna put the original res's back in and see if it works. Btw, i have a pretty goo DMM, but not sure what setting to use to check caps and resistors. Ohms for resistors ?

 

[kc2eeb]

Yep, you use the ohms for resistance. To check caps, the best way is with a DMM that has a cap setting or, better yet, a separate cap tester. Both the resistors and caps have to have at least one lead disconnected from the circuit.

 

[Deisel401]

Ok. . . i put the original resistors back in and all is well. The guy at the electronics store must have given me the wrong value resistors. Def will be double checking all caps and resistors with my DMM from now on before doing any more mods.