Im having a serious pain in my arse and its not gonna be cleared up with a hemoroid cream! I am attempting this mod, mod #2 on this page: www.stocklogic.com/nohum/. I didnt do the treble bleed volume thing but everything else I did do. Ive gone back 3 times now and Im ready to freak! My problem is the volume of the guitar is very low even when I crank the amp. If I turn on my compressor pedal it gets a little louder but not much. There is also still very significant hum. Please any suggestions would be greatly appreciated. Thanks, Damian.
I'm just guessing.. someone more pro (not very high condition) may have better idea... I think you've accidentally reversed some cables.. and now you have there so called "out of phase" circuit.. that would explain low volume.. OR then you have somethin bleeding to ground.. so you lose signal.. only advice: check grounding with multimeter and if it's ok.. it's your circuit... :/ but from mistakes learn we must.. yoda spoken has..
Personally, I've had volume and tone pots whose contacts were so close to the foil on the pickguard underside that this caused bleeding of the signal. Sometimes the output jack wires get twisted and short out. Since you haven't had too many suggestions, how about eliminating the volume control from the circuit and make an appropriate connection to the output? Same thing with the tone control. Well, that's a start.
Post by UnklMickey on Jul 15, 2005 19:02:44 GMT -5
Im having a serious pain in my arse and its not gonna be cleared up with a hemoroid cream!
skip the cream, use Tucks pads instead.
seriously though, some thoughts on your problem:
you've no doubt checked your cable to make sure it wasnt shorted or open.
If you have a short, you will probably still bleed a minute portion of the signal through. You will have to crank the volume a ton on the amp to be able to hear it. The hum louder than normal 'cause the amp is cranked. -- sound familiar.
step one - get a meter (if you don't have one get a cheap dvm from harbor freight, home depot, Lowe's etc. -- $5~$15).
Set it to read resistance (ohms) select a scale on the order of say 20k ohms max.
check for proper operation of the meter by connecting the 2 probe tips together -- should read 0 ohms -- anthing less than 10 ohms is still OK for our tests.
with one end of your cable connected to the guitar, use the meter to check the resistance between tip and shield of the other end of the cable -- should be between 1k ohms and 20k ohms depending on the dc resistance of your pickups and how many are selected. oh, BTW make sure the volume pot on the guitar is not at zero, if it is it will look like a short from the end of the cable.
if you read a low resistance, you have a short. could be the selector switch, a pot connection or the output jack is touching the back shielding in the cavity. if so this will go away when you remove the pick guard from the body. other shorts will be harder to find. look for wiring errors. also, shielded cable can short if the insulation is overheated during soldering.
if the resistance increases significantly when the volume pot is rotated ccw, then goes again to a low value when you reach full ccw, the left side of the volume pot is shorted to it's case or the short is toward the pickups from the volume control.
you can isolate things by disconnecting systematically. if you disconnect the wires to the selector switch and the bridge pickup on switch, at the left side of the volume control, you will now be testing just that portion of the circuit with the volume pot and the output jack. still shorted? look for melted insulation on the shielded cable between the jack and the pot, look for the left or center connection of the pot touching the case of the pot.
just had a thought, that bridge on switch is on the volume pot? new volume pot with integral switch. right value? not 250 ohms instead of 250k ohms or 500 ohms instead of 500k. that would really attenuate the signal.
we've covered some of the possible shorts.
opens are easier: just trace back through the wiring from the tip of the cable to the tip connection of the cable to the center connection of the volume pot to the left side of the volume pot,etc
let's assume the you found the problem and you're ready to re-attach the pickguard. don't re-string until you check the resistance at the end of the cable. if you see the resistance drop with the pickguard in place, it's much easier to just take the pickguard back off and find the short now than after the strings are back in place.
the next trick I'm going to tell you about should be used with caution:
if you have another functional guitar at hand connect it to the amp. set the amp volume at a very LOW playing volume. take a magnetic object (not an actual magnet) that contains cobalt nickel or iron and allow it to touch one of the pole pieces on a pickup thats selected. if it really is a magnetic material is will be attracted to the pole piece. BE CAREFUL! -- if it has sharp corners and is pulled out of your hand, it could scratch something or slamming into the pole piece could impair the health of your pickup. so, you hear that thump through the amp when you touched the pole piece? you can use the same technique to verify that the pickup selector selects right combination of pickups before you restring, or even before you put the pickguard back in the cavity.
hope this helps.
P.S. I'll be on vacation next 2 wks. but I'll check on your progress when i get back.
"Silence is golden, but duct tape is silver. " -- Steve Hopton
"some people say happiness is just a State of mind...................... i think it should be a whole freakin' Country!" -- unklmickey
I shielded a strat a couple of weeks ago that gave me a little trouble. I lined the foil in the body with black electrical tape and fixed a contact problem. It was cheap and quick and lucky me ended up fixing my problem.
Woooohoooo! Dude I fixed it! O.k. for one if you can fit your foot through the computer do this now so it impacts my fanny at a high rate of speed! For one I had the leads mixed up to the output jack!! AHHHHH!!!!! Next I found that one of the leads on the big 1uf cap was touching a tone pot when I was putting the pickgard on. I dont know if the latter had anything to do with my problem. But Im damn sure that the first did. Thanks for all the suggestions especially Unklmickey. I know you spent a while typing that. This site is the cooolest. Thanks Damian