curtisa

The volume pot is in parallel with your pickup, the total resistance will drop (resistors in parallel law). Although I would've thought it wouldn't drop by that much. Are you sure you've got the correct value pot in there, and wired up correctly? An undersized pot will cause the reistance to drop that much, and also reduce the available output too.

What if you get the dual 500K one and wire a 120K resistor in parallel with the two outer lugs of each pot? With the resistors in parallel with the pot elements the total resistance of each element will drop to 96K - pretty damn close to 100K.

Does it have to be 100K? I can find 50K and 500K doing a Google search. You might get lucky if you can lay your hands on an old car stereo or TV maybe?

I think you've got your volume pot wired up wrong too. The output from the pickup needs to go to the "left" lug on the volume pot, not the middle, and the output of the volume pots needs to come from the middle lug, not the left.

You could add an extra switch in series with the capacitor common point and ground - when you throw the switch you "lift" the capacitors from ground.

No ground - it won't work at all, not even through your smaller amp, you'll just end up with a whole heap of noisy garbage. No shielding - guitar will pick up lots of hum through any amp. Ground loop - could cause all sorts of things - hum, buzz, high pitched oscillation, radio pickup. Southpa's comments regarding making contact with the shileding at one point only are valid, although I would've thought that with a solid aluminium body guitar the chances of causing such a loop would be pretty minor - an earth loop requires two or more points earthed at different locations and a degree of resistance in the earth connection to cause anything audible - a solid piece of aluminium the size of a guitar body will have a pretty damn low resistance! Still, I'd be curious to see if his suggestions have an impact - go for it! Something else which just struck me - you've got a solid aluminium bodied guitar with a highly inductive (your pickups) circuit located inside, coupled to a very high gain amp (your 5150). I wonder if by using aluminium as your body material you've inadvertantly created a resonant circuit, like a radio receiver? It could be that by choosing aluminium as your body material you've added too much capacitance to the circuit and it'll oscillate when you apply too much gain For your sake, I hope not! Basically you may have too much "earth"!

I've never heard of the electronics causing what you describe. I'm thinking it's more likely to do with physical factors - the guage of your strings, the age of the strings, how dry your fingertips are when you play. Large guage strings under high tension will nearly always squeak more than smaller guage strings tuned to the same pitch. I use 9-42, or 9-52 on my 7-string, and with a fresh set on the guitars I never have any problems with squeaks. If I leave the strings long enough and let them get really old and crusty, the unwound 1st, 2nd and 3rd strings have a real tendancy to squeak, but only because of the increased amount of gunk on them causing friction that makes a squeaking noise when I rub my hands on the strings. Conversely, I string my acoustic with 10-52's, and the low strings tend to squeak a lot more than the low strings on my electrics. I would think this is due to the higher tension and larger guage - the diameter of the wire used on the wound strings is a lot larger, meaning that the "ridges" along the length of the string are more pronounced, giving you more opportunity to cause a squeak. Kinda like a violin bow rubbing a against a string - the more friction, the louder the noise. I second Spazzy's comment - I wouldn't use candle wax on strings, I don't like what it would do to the wood in your fretboard. There used to be a product made by GHS that was like a special polishing compound to "lube" your strings, but I can't remember what it was called. How sweaty your fretting hand gets while you play may have an impact too. Do you have the same problem with a fresh set of strings? How about if you try it on a guitar with lighter guage strings? You can get flatwound and roundwound strings aswell, but these have a big impact on tone - they tend to sound a lot more rounder and duller, but they don't suffer from the squeaks as much.

I don't think push/pull pots work like that. A PP pot is exactly like a normal p[ot except with a switch that is actuauted by the action of pulling or pushing the shaft. You could wire it up so that the switch selects which pickup is passed to the volume control, but you can't set the volumes independantly - it's still just one pot.

You can't get any better shielding than a solid lump of aluminium Provided you have continuity between the ring of the output jack and somewhere on the body, trust me, it's well shielded! I was going to suggest a microphonic pickup. 'Course it could be the amp? Can you make the squealing come and go if you back off the volume control?

Hi Telemaster, Here's the blend pot modification I've found. Basically it's exactly the same as yours except for the addition of the tapering resistors across each input of the blend pot: http://i153.photobucket.com/albums/s222/ac1176/blendpot.gif All the rest of the diagram has been omitted for clarity - it should just substitute straight in as is. The pot has to be a linear taper type. Cheers, Curtis.

3 bucks??? Highway robbery!!!! Just kidding... Yeah, it'll work fine. I'd prefer to have something with a capacitance measurement function aswell, this one for example: http://www.harborfreight.com/cpi/ctaf/disp...temnumber=37772 ...which also falls under your $20 budget.

Looks like it'll work fine to me

Lose the resistor in parallel with the capacitor - I think this is where your highs are being shunted when you alter the tone control. You'll probably find that you'll have to fiddle a bit with different value capacitors to get the right sound you're after. Don't forget that your pickups are indirectly also part of the circuit, predominantly inductive and resistive, which will have an effect on the frequency response of the mid cut circuit. Just grab a fist full of different value capacitors and a pair of aligator clips and start swapping them in and out. Smaller values of capacitance will increase the frequency of the mid cut, larger values will reduce the mid cut frequency. This page may also help a bit too: http://home.online.no/~jaeioluf/sound/eqpassiv.htm

The pot really needs to be a dual log/antilog type to get the correct feel out of it. You'll have a hard time trying to find one at a reasonable cost. The next best thing will be a dual linear pot with tapering resistors around it. After that you may get acceptable results just using a linear pot with no resistors, but you'll probably still end up with the same volume drop problem you're already experiencing. Just check to make sure you've got the right pot from Stewmac - use an ohmmeter, set the pot to mid rotation, and measure the middle lug to either outside lug of each element . If it's linear taper you'll have half the total resistance between middle and outside for both elements. If it's dual log you'll have about 60% across one side and 30% across the other for both elements. If it's dual log/antilog you'll have 60/30 on one element and 30/60 on the other. Basically the dual log/antilog pot will work exactly as you've drawn that diagram (with the earth of course), the dual linear pot will need the tapering resistors, and the dual log pot will never work in this application. I have a wiring diagram at home for a blend control using a dual linear taper pot and the additional tapering resistors. I'll see if I can dig it out tonight.

Ahhhh yes, he's right Check out http://www.stewmac.com/freeinfo/i-4137.html for the whole story.

I think you have the balance pot wired up funny. With the pot in mid rotation you'll have half the total resistance of the pot in series with each pickup, which will cause the drop in volume you're experiencing. I think the proper way to do it is to shunt each pickup's output to ground, not to add more resistance in series with them, kinda like the volume control, plus you'll need "tapering" resistors around the balance pot to get a good blending characteristic. I'll have a think about it, don't have much time at the moment, hang tight in the meantime

Neck pickup is out-of-phase with the bridge? Balance pot is too low value? Got a schematic handy?

Having actually tried the piezo-buzzer-on-the-bridge-block trick myself I can say that it sounds like pants. The bridge block is not the optimum place to position these piezo units as it picks up as much string vibration as it does the vibration of the tremelo springs themselves. It does work, but it doesn't sound particularly nice. There is a reason that piezo units are mounted in the saddles One alternative that has been suggested, and that I haven't tried myself, is to fit the piezo buzzer unit between the neck and body in the neck pocket. I would imagine however that it aint going to sound anywhere near like an actual piezo saddle system. Approach with an open mind and expect anything.

Is this an already-built guitar? Chances are it already has shielding in the control cavity if it is. If it's not earthed to another part of the instrument, say through the bridge or output jack, you'll need to provide an earth for it. With the guitar assembled check for continuity between the cavity shielding and the output jack shield using an ohm meter. If there's continuity between the two, you don't need to earth the cavity shield. If this is a new guitar you'll probably need to apply shielding to the cavity in the form of either conductive paint or sheets of self-adhesive foil. Both should be available from your guitar parts supplier. An easy way to connect the shielding to the jack is to make a connection to the collar of the toggle switches. Most switches have conductive bodies that should come in contact with the cavity shielding once the guitar is assembled. If you have the switch body in contact with the cavity shileding, you can use that to your advantage and easily solder a wire to a washer that sits on the collar of the switch, and return the wire back to the output jack shield. That being said, you may even get away with no shielding at all. If the pickups you're using are humbucking you may find the guitar is hum-free anyway. I have a guitar with very little cavity shielding and a bridge humbucker that's dead quiet, even when run through the most high-gain amp.

Yes, your bridge needs to be grounded as it acts an earthing point for your strings aswell - ever tried taking your hands off the instrument when plugged into a high-gain amp? Lotsa buzz. If you don't have the bridge and strings earthed your guitar will buzz badly 24/7, whether your hands are on the strings or not. If you're dispensing with volume/tone controls I'd be grounding the bridge, control cavity shielding (if applicable), the "cold" side of the two pickups, and running the wires back to the shield connection of the jack socket. Make the shield connection on your jack socket the star ground point. Run one wire from this point out to each point in the guitar to be grounded - pickups x2, bridge, control cavity - four ground wires in total, 3 if you don't need to ground the control cavity shielding.

Without knowing how the unit works I couldn't really say. The manual makes mention of using a standard insert lead when using the pedal for expression duties - do you have such a lead? Can you make the pedal work in expression mode with the SE70 anyway? Sorry, I've got no idea how the pedal achieves the functions that it does. If you can't make it work the way you just described it, I would guess that it's going to be a hack-up job to do it, requiring a reasonable working knowledge of electronics, and voiding any warranty on the unit in the process. I'd be doing all that kind of crazy multiple-paramater controlling through MIDI, but then I'm a bit of a control nut anyway

Can't help you with the tone pot size thing, but yes, 47nF is indeed 0.047uF

Looks like it's in the input stage of the amp, doubt it's the cause of your problem, but I have no idea why only 2 of 3 legs would be connected. Some kind of mod by a previous owner maybe? Bah! Need the schematic Sounds like you've found the problem, and yep, you've got it connected right. Well, the easy solution is to leave the lead plugged in but it certainly isn't the most elegant solution. Have a closer look at the effects loop jacks when you get a chance. If they're the same type as the input jacks (which I can just see in the bottom-left corner of that photo you posted), they'll have little metal tabs that are shorted across the top of the jack when no lead is plugged in, and that lift up when the lead is inserted - you can try cleaning the point where the two contacts meet with isolpropyl alcohol (will be damn fiddly though). You may also get good results if you use extremely fine wet-and-dry paper, fold it in half, and slide it in and out a few times between each contact. Also check that each pair of tabs actually meet when the jack is removed from the socket. Check the solder joints on the sockets underneath the circuit board - look for any cracked or fractured solder joints and remelt any that might be there. You may need a magnifying glass and strong light to see any really fine cracks. Hope that helps

Did the volume gradually fade out, or suddenly cut off? One channel or both? I used to have one of the old Peavey Express amps that had dodgy effects loops jacks - the contacts on them would occasionally open up and result in a sudden loss of volume. Plugging a lead in and out of the sockets a few times would temporarily fix the problem until the contacts gradually opened up again. Replacing the jacks would permanently fix the problem, cleaning them would also work. If the volume drops again, you can test the effects loop jacks by plugging a lead from the effects send jack to the effects return jack. If the volume comes back up when you plug in to the loop, one or both of the effects loop jacks are probably the problem. This may sound kinda stupid, but if you hit the amp can you make the problem come and go? That would indicate the problem is to do with loose connections, dry solder joints or other poor connections. Without seeing a schematic for the amp I couldn't tell you if that transistor is meant to be soldered like the way you say. Can you post a photo of the offending component and surrounding circuit board? If the amp initially worked for a while before dropping out I would guess that the transistor isn't the problem. Another one to check, if your amp is fitted with it, is the external speaker socket - if it's designed to bypass the internal speaker when a lead is plugged in it can develop the same problem as the effects loop jacks. Beyond that I'd be looking at the circuit board itself and checking for fractured traces or fractured solder joints. I once fixed a Peavey VTM60 head that would drop in volume randomly. The problem was traced back to a resistor with a cracked body - replacing the resistor fixed the problem. Cheers, Curtis.

Maaaaaybe. LED light output tends be pretty non-linear with respect to applied voltage. You'll probably find that the LED bightness will only start to noticably dim when the battery voltage gets critically low, by which time it's probably too late anyway! You may be able to "fudge" it slightly by using a larger-than-normal value resistor so that the LED current is only just above the minimum needed to light the LED when the battery voltage is healthy - experiment with different value resistors. Good luck! Cheers, Curtis.