Hi all
Hopefully some of you more knowledgeable types will be able to shed some light on this problem and stop me from going mad!
My main Strat is a vintage style partscaster. A couple of years ago I had the pickups changed by my local music shop's workshop, and at the same time I had them rewire it with new pots, as the original ones were always very stiff. A few weeks ago I took the scratchplate up, and saw that instead of being standard vintage correct wiring, it had a length of Gibson shielded wire. This wire took the positive from the middle lug of the volume pot, and then the outer shielding took the earth from the side of the neck tone pot, then it was soldered to the side of the other tone pot, before going to the jack socket in the usual way (with some insulation around it to stop any shorting). The earth to the trem claw came off the volume pot body as it should, as did an earth wire to the shielding paint in the cavity (strangely the volume pot didn't have an earth feed going to the jack, although it was probably using the aluminium shield OK)
So last weekend I decided to wire it back to vintage correct, using cloth push back wire. For now I left off the earth to the cavity paint, but otherwise it went back as per vintage spec - positive from middle lug on vol pot to jack, earth from vol pot body to jack, earth from vol pot body to trem claw. When I plugged in to test it afterwards I thought it sounded a little thinner than before, but thought I must have imagined it. However, at the band rehearsal today I found that it is definitely sounding thinner. With amp and pedals set the same as usual it is not as full sounding, and is not driving the drive pedals and amp as hard as before the change. It doesn't sound bad or wrong, and if you didn't know how it sounded before you probably wouldn't notice, but it really threw me at rehearsal!
Anyway, sorry for the long post. Can anyone shed some light on what might have occurred? I did wonder if I had managed to overheat one or more of the pots, despite trying to be careful (my wiring skills are not that developed, although I don't usually have any problems). Here is a photo of part of the wiring as it was previously:
Thanks
Mike
Comments
There is no advantage to 'vintage correct' unshielded cable between the volume pot and the jack - it will do nothing other than increase noise - and shielding does take off a tiny bit of top-end by adding a little capacitance to the circuit.
The apparent loss of gain is probably because the resonant frequency has been altered slightly by the capacitance change and isn't in the right place to maximise output as it was before.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Did you put the same strings back on just to test things or did you replace them with a brand new set? If you changed strings, were the new ones the same gauge as last time or did you go lighter this time?
Annoyingly I cut the old shielded wire before unsoldering so I’ll have to get hold of some more before I tackle it.
Thanks for for the help and wise words.
Shielding does make quite a difference to the tone. When I was first starting out with a cheap Strat-style guitar, I followed some advice in a book on how to thoroughly shield the whole thing to stop the noise, so I did - it took half a day since it was basically covering everything, including the insides of the pickup covers, with copper tape, and replacing all the wiring with shielded cable. Then feeling very satisfied I plugged in the guitar... no noise, but I thought the tone control had gone faulty because it sounded like it was turned halfway down even when it was full up. I took a lot of fruitless troubleshooting before I finally realised it was the shielding. I had to take about half of it back out before the tone was anything like normal.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Yes, connecting a shielded cable from the volume pot to the jack and then a separate ground wire to the tone pots is fine. In fact, as long as the pickguard shield contacts to the pots are good you don't actually need the ground wire - at worst, if the contact fails al that will happen is that the tone control doesn't work.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Many thanks again - it’s much appreciated.
Mike