Chip Zempel is a guitarist who has kindly agreed to let me post some of his technical how-to's here as part of the Epiphone Emperor II, Joe Pass model Appreciation page.
INDEX:
You can email Chip at czempel@ns.net.
Tone Capacitors
>Hi Chip, > >Doing a DejaNews search, I ran across a write up you did on the Epi Joe >Pass. I recently bought one and I'm getting ready to do some mods to it. You >mentioned in your post changing the tone control caps. What does this do? >The tone controls on mine are very effective. Does changing the caps help >with this? I love the deep, warm, full sound, but I would like for the high >strings to come out a little better. I'm thinking of changing to Seth >Lover's to see if they help. What have you heard about Seth Lover's on this >guitar. Thanks for the nice write up. > >Greg > Greg- If you are happy with your tone controls, don't change them! Tone controls work by cutting high frequencies. As you turn the control, more and more of the highs get bled off to ground through the capacitor. The higher the value of the capacitor, the lower the point at which the capacitor starts to have an effect. Let's see if I can "draw" a graph using ASCII. (This will look like hell if you don't view it with a monospaced font like courier!) | roll-off frequency | v |-------------------------------------------------------- flat volume | * | * | * | * | * | * | ---------------------------------------------------------- bass -- frequency -- treble "Flat" above is with the tone control turned all the way "up" so that no highs are being bled off to ground. The other line with the asterisks "*" shows what happens when the tone control is turned down, to cut the trebles. How much you turn the control determines how steep the line angles downward, but the point at which the line starts to bend - the roll-off frequency - stays the same whether the tone control is turned a little or a lot. Does that make sense? If you turn the tone control only a little, the line dips just a little, but it still starts to bend at that same point. The more you turn the control, the sharper the bend, but it still starts to bend at the same point. Think of it like a hinge. The thing that determines the roll-off frequency is the value of the capacitor. The higher the value of the capacitor, the more the roll-off frequency moves towards the bass side. My Epi JP came with 0.100uF (microFarad) capacitors on both tone controls. (Actually, they were labelled "100N" which stands for 100 nanoFarads, which converts to 0.100uF.) This is a very high value! The Gibson ES175D (which is a fairly comparable guitar to the JP - hollow body, laminate top and dual humbuckers) usually comes with capacitors half that value - .050uF. I installed some .047uF capacitors that I found at Radio Shack and a much happier with them. If you're good with a soldering iron, this is an easy replacement, but if you're not, have someone else do it. It should be a really simple (ie, inexpensive) job for your local guitar tech. (I'm not sure that all JPs come with these capacitors, either. I wouldn't be surprised if yours are different.) The main thing that I didn't like was that turning the tone control even a little bit seemed to just about wipe out any trebles I had. Turning it farther seemed to cut just about everything - it seemed to be acting more like a volume control than a tone control. Keep in mind that I'm mainly into jazz playing and don't want or need a really wide range of sounds - I'd rather be able to make small, subtle differences in my tone. If you aren't happy with the highs, even when you've got the tone control all the way up, changing the capacitor won't make any difference. When the tone control is all the way up, the capacitor is out of the circuit. For more highs, you have to look elsewhere - different strings, different pickups, different amp, or different cable. (Guitar cables act like capacitors, too. A high quality cable can make a big difference!) I have indeed heard good things about the Seth Lover pickups on this guitar, but it doesn't make a whole lot of sense to me to spend $500 for a guitar and then another $200 upgrading the pickups. (Of course, your mileage may vary.) I'm not sure what the Seth Lovers cost, but I would guess that they're probably about $100 each, installed. Maybe you might just replace the neck pickup first? You might try searching DejaNews for "Seth Lover" or something like that. Don't forget strings, too. For $50 or $60, you can get a lot of different kinds of strings to experiment with. Below, I'm attaching another letter that I wrote to someone else about my JP and my experiments with it. I hope you find it helpful. Since I wrote it, I tried the last two sets of strings. I liked the La Bella Tapewound strings a lot, but the bottom E was too fat for the nut. If I were only playing jazz, I would probably have widened the nut and stayed with those strings. But the TI BeBops had a brighter, more versatile sound, and those are the ones I've decided to stick with, at least for now. Good luck, and let me know how things turn out. Chip ------------------
Which Strings?
>Chip, > >I have as JP Epi too, if you do not mind, could you tell me what strings >you used on it and what caps value you used. I really like this guitar >but it never hurts to sound better. I have been contemplating a pickup >change although I have been told that this model has better pickups than >most Epiphones, but that was not a reliable source. I really do not have >any other archtop experience to compare except at shops, then you are >playing with a different amp, so comparisons are not real easy. thanks >for any info. > Before I tell you anything else, here are a few things to keep in mind about who I am and what I'm looking for: The Epi Joe Pass is not only my first archtop, but also my first electric. I've been playing classical and a little steel-string for more than 30 years, but now my main interest is learning jazz guitar, so I bought the JP. I've had it for about six months. Keep in mind that, first of all, I haven't been around electric guitars before, I'm interested in what I guess you'd call a "traditional jazz sound" (clean, warm, mid-rangey), and I play fingerstyle almost exclusively. And for what it's worth, I am playing through a Fender Princeton Chorus, a 2x25 watt solid state amp with a pair of 10" speakers. STRINGS The bass on my JP - especially the low "E" - really sounded dull and weak when I first got it. It came with some sort of light gauge, rock'n'roll strings. I replaced them with D'Addario Chrome 12s (see below) and things got better. But I was still dissatisfied with the sound, especially the bass. With a relatively shallow body and an amp with two 10" speakers, I'm not expecting (or interested in) a lot of bass. But even before I got the amp, I didn't like the way the lower strings sounded. Getting the amp and plugging the JP into it only confirmed the way I thought it sounded unplugged - the bass just wasn't there. My suspicion is that if an archtop guitar doesn't sound good unplugged, it isn't going to sound good amplified either. (At least, if you're looking for the kind of tone that I'm looking for.) In the last couple of months, I have tried several different set of strings. I plan to post a message to rec.music.makers.guitar.jazz when all this experimenting is done. But since you asked, I'll give you an interim report. Here's what I am trying out: D'Addario Chrome 12s D'Addario Chrome 13s Thomastik-Infeld Jazz Swing 13s Thomastik-Infeld Jazz Bebop 13s ------- I'm on these right now D'Addario Half-Round Series II 13s La Bella Nylon Tape Wound 14s I've been replacing strings about every three weeks, so that they haven't had much of a chance to lose their sound. (I don't want to be comparing dead strings of one brand to fresh strings of another!) The D'Add Chrome 12s were better than the strings that originally came on the guitar, but they were still pretty disappointing. The low E string was very dull sounding, plugged in or acoustic - just sort of a "thump". The D'Add Chrome 13s were a little better. The TI 13s were MUCH better to my taste. The bass finally sounded like something! It had some pitch! Some sustain! All three of these sets are flatwounds. The TI Bebop 13s are round-wound strings, but the windings are very fine and don't squeal nearly as much as normal strings. I am in love with these strings! They're a little brighter sounding than any of the flatwounds, which has helped bring the bass alive even more, and I have compensated for the extra brightness in the higher strings by rolling off the treble a little. (Remember, I'm seeking a "jazz" tone.) I would have adjusted the pole pieces in my pickups for these strings too, but since I'm going to be changing them again this week, I haven't bothered. I also noticed that the package for the TI Swing 13s (the flatwounds) called them "mediums" but the package for the Bebop 13s called them "medium-lights". The tension listed on the package is indeed lower for the Bebops, and I've noticed a little bit of fret buzzing. I would probably adjust the truss rod if I were sure I was going to stay with these strings, but I have a few more sets to try yet. I might try a set of 14s before I'm all done experimenting, but right now, these are my favorites. The TI Swings are my second favorites, and both D'Addarios are much lower on my list. The D'Addario Half-Rounds (which I haven't tried yet) start out as a round-wound string and then they're ground down a bit so that they're somewhere in between flat-wound and round-wound. Haven't tried them yet. And the La Bellas (which I haven't tried yet, either) are steel strings wound with flat nylon tape on the lower strings. (In England, flat-wound strings are called "tape-wound"). They are very cool looking - the nylon is _black_ which ought to look great with the gold hardware and natural finish on my JP! Several people in the jazz guitar newsgroup have said good things about them. Despite their thickness, they pitch-bend more easily with other 13 gauge brands. (I never noticed how much bending I do until I got a guitar with heavy strings on it!) One potential problem, though, is that they are very thick - the low E is a .067! (Yes, I've doubled checked that - it's not a typo.) A lot of people have to have their nut refiled to make them fit. (Don't know what I'm going to do about this if it comes to that!) The six sets of strings above set me back quite a bit (those TIs are particularly expensive), but I didn't even hesitate. A long time ago, I became a big believer in experimenting with strings. The right set of strings can make a TREMENDOUS difference in the way a guitar sounds. If you've never gone to the trouble and expense of trying a lot of strings in a (semi-) controlled fashion, it can be a real eye-opener. Even within the same brand, just going one step up or down in gauge can make a _huge_ difference! (BTW, there are several places on the internet that sell hard-to-find strings at very good prices. Two that I have used and been very satisfied with are Mostly Strings and Just Strings. I don't have their URLs handy, but you should be able to find them with a search engine.) Anyway, when I finish trying out all these strings, I'll post a review in rmmgj. (It probably won't be until January because I do a lot of gigs during the holidays.) CAPACITORS I was very unhappy with the tone controls on my JP - turning down the treble seemed to me like it cut _way_ too much. It was almost like I had two volume controls! (From some of the things I've read, I wonder if there are Epi JPs with different capacitors (and maybe even different pots!) floating around. I'm not sure if they're all the same or not...) But mine had .100 uF (microfarad) caps on both tone controls. (The tone controls were 500k ohms, BTW.) They say "100N" on them, "N" standing for nanofarad, one-thousandth of a microfarad. I read somewhere that most Gibsons with humbuckers come with .050 uF caps, so I replaced them with Radio Shack .047 MFD capacitors, catalog no. 272-1068. As I recall, a package of two was less than a dollar. If you're handy with a soldering iron, it's a relatively easy replacement. (Getting the controls back into their holes was much more of a challenge - use a piece of string tied around the control shaft to fish them back into place.) Replacing the capacitors made a world of difference - all of a sudden, I have a lot of useful sounds and the pickup switch and tone controls on my amp and my guitar all seem to make sense now. They're working together! I'm not sure how much of this may be due to my just getting more used to playing electric guitar, and getting to know my guitar and amp better - but I think it's mostly due to changing the capacitors! (But remember that I'm mainly interested in a "traditional jazz sound" rather than rock or blues types of sounds.) All in all, I am very happy with the way my guitar sounds right now! PICKUPS I've heard a lot of people complain about the Epi pickups. (I've also heard that they've recently started putting better ones in, but I suspect that mine is old enough that it didn't get these new ones, if they exist.) I'm trying to get as good a sound as I can out of what I got, and I'm getting pretty satisfied with it. The two pickups I've heard mentioned most often in a jazz context are Gibsons (I'm not sure what model - I think there are a few) and the Seth Lover pickups made by Seymour Duncan. (I think Seth Lover was the guy who designed the original Gibson humbuckers, or something like that.) I'm keeping that information in the back of my mind, but for right now, as I said, I'm pretty happy with the sound I'm getting. (To be honest, I think there's more improvement to be gained at this point from working on my playing rather than spending any more dough on hardware!) I think the Gibsons are around $95-100 each and the SDs are a bit less - maybe $65-75. I'm not sure. The only thing I don't like about my JPs pickups is that they seem to buzz and rattle sometimes, at certain frequencies. I'm not talking about microphonics. I hear it mostly when I'm playing unplugged. The sound doesn't show up much amplified, but I still hear it. I think it's the springs around the adjusting screws, or the pickups vibrating against the little thing that surrounds them. I've solved this (temporarily) by wedging a pick between the pickup and the surround to keep it from vibrating. I also understand that some vibrations and some of the feedback that happens at high volumes with these guitars (not a problem for the type of playing I've been doing) can be traced to the wire tailpiece. Some people have recommended threading a strip of felt through the strings between the bridge and the tailpiece. Others have recommended replacing the tailpiece with a wooden one. (Now THAT sounds cool - I can just picture my guitar with black strings and an ebony tailpiece!) For now, I'm not going to mess with any of this. OTHER (COSMETIC) MODS There are a couple of other things I've done that you might be interested in, just to make the guitar look a little better (in my opinion). I used some "Goof Off" to remove the "Joe Pass" signature from the pickguard. Goof Off is a pretty nasty solvent, for removing paint that has already dried. You can probably get it at the paint counter in most hardware stores. Just to be extra careful, I removed the pickguard from the guitar before trying this - I didn't want to take a chance on spilling Goof Off on my axe! I also pre-tested the Goof Off on the back of the pickguard to make sure it wasn't going to harm the plastic - you might want to do this too, just in case Goof Off has changed their formula or Epi has changed their plastic! Be careful not to remove the pinstripes around the edge of the pickguard (unless of course, you want to). They're painted on, too. (And, for what it's worth, I left the Joe Pass signature on the truss rod cover at the head.) I also peeled off the Epiphone "sigma" logo from the pickguard - it's stuck on with some sort of double-stick tape or something. To be honest, I don't remember what I used to remove the glue that was left. It might have been rubber cement thinner. Whatever you use (if you do this), be sure to test it on the back of the pickguard to make sure you aren't going to harm the plastic! I also removed the black "Treble - Rhythm" ring around the pickup selector switch. I'm not sure why, but that always bothered me. Kind of like if your car came with "Gas" and "Brake" on the pedals, if you know what I mean. If I had known how much trouble removing this was going to be, I'm not sure I would have done it. It's REALLY stuck on, with some really strong adhesive! (I think the fact that it was screwed down by the retaining ring around the switch was part of the reason it was stuck so tightly to top of the guitar.) Anyway, I finally ended up prying it off very carefully with a plastic putty knife and using ammonia - and a whole lot of scrubbing with a soft rag - to get the glue off. Jeez, what a job! It's probably a good thing that they use polyurethane or whatever it is to finish these guitars. Anything more delicate, and I probably would have wrecked the finish! DISCLAIMER What's that old saying about fools being lucky, or something like that? A lot of the mods I did, I went into kind of blindly, and lucky me, (knock on wood), everything came out fine. Please don't try any of this stuff (aside from experimenting with different strings - I assume you can handle that!) unless you feel up to it, or you're willing (like I was) to pay the consequences if you screw something up. Please don't blame me if something goes wrong! (But if you have more questions, feel free to ask!) Good luck, Chip Zempel