Eastman 905CE - Pickups

[Tim Z]

I just received a brand new Eastman 905ce this week and have a few questions about it.

1) It has the Kent Armstrong floating humbucker with the gold metal cover. Every time I touch the metal cover the guitar buzzes really bad. This is extremely annoying as I tend to want to play near the pickup and my thumb is constantly touching it. Is this normal? Assuming it is not, what can I do about it?

2) It appears that both the tone and volume pots are linear taper. I can't understand why anyone would put a linear taper pot in a guitar as it really limits the sweep and usability. Anyway, as this is my first ever guitar with a floating pickup and pots under the pickguard, does anyone know if these pots can be replaced with audio taper pots? And where can I purchase them from?

Other than these issues, the guitar is very nice and appears to be very well built.

Much appreciated
Tim

[73Fender]

Regarding the buzzing issue this occurred for me once when I had the output jack leads reversed. In my case it would buzz when I would touch any metal part, strings included. Sounds like a grounding issue. Good luck.

[sgosnell]

The buzzing is not normal, and should be fixed. It's probably either a loose ground or a miswired pickup. I've seen miswiring in Eastmans before. As for pots, they're available from many sources. I use Arkansas Music Works on ebay a lot. I've had good service, and prompt shipping from them. Mouser Electronics sells all sorts of electronic parts, and has a wide variety of pots available. StewMac sells them, but not cheaply. AllParts also has them. Make sure you get the correct size pot, with the correct shaft and housing diameter so you don't have to ream new holes in the top nor buy new knobs.

[Tim Z]

Thanks very much for the replies. I will check the wiring and ground connections. Note, the 905ce has a floating pickup with the volume and tone controls are hidden under the pickguard. I do not get any buzzing at all when touching the strings; only when I touch the pickup cover. So are these pickups grounded at the tailpiece where the jack is? I have wired dozens of guitars, but they are all Strats, Tele's and Les Pauls. Not familiar with this type.

With regards to the pots, these are not the typical size pots you find in most guitars. Since this is my first floating pickup guitar, I am not familiar with these kind of pots. Guess I will have to take the pickguard off and have a look at them and the specs on them. Do all those sources sell these kind of pots? I also need to make sure they are "A" taper. The ones I see at Stew Mac don't say, so I guess I will have to email them first to confirm.

[sgosnell]

Probably you have Schatten thumbwheels. That's pretty much the standard. But you can find others here: Guitar Parts Factory - Mini Potentiometers

Scroll all the way to the bottom. One is definitely linear taper, but I'm not sure of the other two. One is 250k, one is 500k, and I assume audio, but that might not be a valid assumption. As far as I can tell, it's this one from WD Music, and you can buy direct if you prefer. WD definitely says theirs are audio taper.

Alpha® Thumbwheel Potentiometer 250 kohm - 500 kohm

[Tim Z]

Thanks for the help sgosnell. I will check those out. I definitely want/need audio taper thumbwheels. I will also have to measure the impedance on these stock thumbwheels to see if they are 250k or 500k. I'll see if there are any suppliers in Canada.

I checked the wiring and I cannot see anything wrong that would cause this buzzing. It all looks clean with good solid solder joints. The only thing that could possibly be wrong is if they reversed the ground and lead from the pots to the jack, but even then, I am not sure it would cause the same buzzing. It may actually be a faulty pickup? As it is, the guitar is basically unplayable, as the buzzing is there all the time and can be heard in recordings. It gets much worse if I touch the pickup cover, but is still there quietly even without touching it. The guitar is under warranty, but it took 6 weeks to get here from the warehouse in California through the store I bought it from in Edmonton. The last thing I want to have to do is ship it back to wherever it would have to go for warranty servicing. You would think Eastman would triple check their top of the line model before shipping it out!!

[sgosnell]

Having the pickup positive and negative reversed could cause the buzz. Someone else had the same problem on here recently, and that was the cause. I have an Eastman T145 that had the pickup wired incorrectly, AFAICT from the factory. It worked, but it didn't sound good. After I rewired it to the Armstrong specs, it sounds great. Surprisingly, since they make most of the electronics for the world, the Chinese don't seem to have adequate knowledge of wiring them up.

For the pots, generally single-coil pickups use 250k, and humbuckers use 500k. It's not a legal requirement, but that's what most people prefer. Humbuckers tend to be darker, so 500k pots brighten them up a little. Single-coils are brighter, and the 250k pots tame that to some extent. I just remembered that I had a set of the 250k thumbwheels from Guitar Parts Factory on hand, left over from a previous project. I dug them out and replaced the 500k Schattens with them, on my Wu with a DeArmond Rhythm Chief single-coil pickup. They're definitely audio taper.

[deacon Mark]

If it were me i would simply put a new CTS pot in and only use one volume control no tone. You have a loose
ground or reversed wire on jack. I recently wire on wrong on a mini jack not paying attention same problem as you with noise.

[Tim Z]

I believe you are correct and it is a problem with the ground and leads being reversed somewhere. I measured the impedance between the pickup cover and the jack and get a reading of 7.66. This should read zero! So there is a problem. Problem for me is that I am not familiar with these thumbwheel type controls. I can see that the lead and ground are correct at the jack, and can only assume they are coming off the correct terminals on the pickup, but I have no idea where they should be at the thumbwheel. Guess I will have to find a wiring diagram for this to correct it. Man, what PITA though. How can they send out there highest level guitar without even making sure this is all correct. So far, not impressed with Eastman's quality control. I aslo notice that whoever drilled the hole for the jack, did a horrible mess of a job, with wood chipped all off on the inside. I will deal with this buzzing issue first and then see about the thumbwheels after it is wired correctly.

Deacon Mark I am not following you on the CTS pot thing. I have used tons of CTS pots in my time, but are you saying CTS makes a thumbwheel pot that will go under the pickguard like these stock ones? There is no way I am drilling holes in either the top or the pickguard to install a typical CTS pot. Besides that, I definitely want/need a tone pot for a jazz guitar.

I have also sent an email off to Eastman telling them of these issues and also making it clear that I am NOT impressed!

[sgosnell]

My guess (and it's only a WAG without seeing anything) is that the pickup leads are wired backwards, or else there is a short between some leads on the thumbwheels. I can post a wiring diagram if you need it, from Benedetto. It's not with thumbwheel pots, but there is no real difference. You do need to know that the diagram shows the pots upside down, and the actual thumbwheels are right-side up when you view the terminals, so you have to reverse the connections. I just ran into that. If you don't, the pots work backwards for me, so turning clockwise reduces the volume and tone instead of increasing it, and fully clockwise is off. Just picture the thumbwheels from the other side, if that makes sense.

[Tim Z]

Thanks Man . . . . . I'll try reversing the wires tomorrow and post back if it fixes it. If you can post a wiring diagram, that would be great.

[sgosnell]

Bravo wiring diagram.pdf

This is my preferred wiring scheme, because it gives the same tone from full volume to cutoff, or at least a very close approximation.

The Armstrong wiring diagrams are here: http://www.kentarmstrong.com/schemat...structions.pdf

[ugarte]

From my experience with rewiring a couple Eastmans I suspect the problem is with the tailpiece ground wire. I don't know how Eastman does it but the internal wiring is remarkably tight - like no slack on any of the leads to the point where a little rotation on the jack (or a pot on those models) can introduce enough tension to break a solder joint.

[deacon Mark]

I believe you are correct and it is a problem with the ground and leads being reversed somewhere. I measured the impedance between the pickup cover and the jack and get a reading of 7.66. This should read zero! So there is a problem. Problem for me is that I am not familiar with these thumbwheel type controls. I can see that the lead and ground are correct at the jack, and can only assume they are coming off the correct terminals on the pickup, but I have no idea where they should be at the thumbwheel. Guess I will have to find a wiring diagram for this to correct it. Man, what PITA though. How can they send out there highest level guitar without even making sure this is all correct. So far, not impressed with Eastman's quality control. I aslo notice that whoever drilled the hole for the jack, did a horrible mess of a job, with wood chipped all off on the inside. I will deal with this buzzing issue first and then see about the thumbwheels after it is wired correctly.

Deacon Mark I am not following you on the CTS pot thing. I have used tons of CTS pots in my time, but are you saying CTS makes a thumbwheel pot that will go under the pickguard like these stock ones? There is no way I am drilling holes in either the top or the pickguard to install a typical CTS pot. Besides that, I definitely want/need a tone pot for a jazz guitar.

I have also sent an email off to Eastman telling them of these issues and also making it clear that I am NOT impressed![/Quot
I would not use the thumbwheel pots I just do not think they are substantial for the most part. Since it is an Eastman I would put a CTS 500k pot on the pickguard and only use a single volume pot. This will run the pickup wide open and you can adjust the tone with the amp. I have never been a fan of a tone control for the most part. They take up extra space an rob the simplicity of the whole floating pickup set up.

I have my for the most part Dearmond 1100 with a single mini volume pot I believe it is a 1000k pot so really wide open better than a 500k. These are on my Barkers and the D'angelico they require a small 1/8th mini plug at the pickguard. If I need to adjust the tone then I do on the amp. When ever I play a single pickup guard like Wes L5. I have the tone dialed completely up and never change it while I am playing. Tone controls to me are like worn out running shoes...………..they are not helping anything I need to throw them out.

[Tim Z]

Thanks for all the responses. This morning I took it apart again and it was immediately obvious that they wired the lead and ground wrong (reversed) at the pickup. The fix was as simple as reversing those two wires at the pickup. Buzz is now gone and the guitar is very quiet. Now to actually get to playing my new guitar with the pickup.

FWIW, the thumbwheel pots in this guitar are 500k A. So they are audio tapers. Just do not work like any A taper pots I have used in all my other guitars. Not a big deal for me though, as this guitar will primarily be used for recording purposes, I can take as much time as I want to dial in the tone. For live situations, I would never ever want to have to be adjusting my amp(s) for each song at gigs

[sgosnell]

500 kOhm does not equal audio taper. The resistance has nothing to do with the taper.

I don't agree with the deacon about thumbwheels, I like them. I far prefer using them instead of clumsy big pots and knobs on my pickguards. My Wu doesn't even have a pickguard, the Rhythm Chief pickup is held in place with Blutack and the thumbwheels are inside the body, accessible through the f hole. But that's a subjective choice, and regular pots do work.

[rpguitar]

I don't think he's stating that 500k is equivalent to audio taper. Note the statement, boldface addition is mine. A capital "A" is probably stamped on the pot, and it's interpreted to mean "Audio."

"FWIW, the thumbwheel pots in this guitar are 500k A."

[Tim Z]

rpguitar is correct The pots are stamped "500k A" which means audio taper. I have been working on and wiring guitars for many many years, so I do know the difference between audio and linear taper pots

With regards to Thumbwheels vs regular pots, remember this is my first ever solid wood jazz guitar. The reason they use floating pickups on these guitars is to not drill into or limit the affect on the spruce soundboard. This is also quite a pretty guitar, so not a chance that I am going to be drilling holes into the soundboard or the ebony pickguard and lowering the value of the guitar. Not to mention also likely voiding the warranty. Perhaps in 5 years down the road I might think of doing something that crazy to it, but not a brand new $3000 guitar that I have barely played yet.

[deacon Mark]

I was not suggesting drilling into the top of the guitar at all that would be crazy. I was suggesting to drill into the ebony pickguard that is attached only by brackets. If you put a pot on the pickguard as they are usually mounted this would do nothing at all to de-value the guitar. I just find them much easier to adjust volume rather than the small thumbwheels.

[Tim Z]

I have only had this new Eastman 905ce for a week now, but have been recording with it a fair bit the over that period. The stock Kent Armstrong gold covered pickup (which I assume is the Chinese version) sounds pretty good, but I have very little experience with other floating pickups on jazz archtops and wonder if it could be better. In another post of mine here, someone suggested that I immediately switch the pickup to an American handmade Kent Armstrong with the double row of poles (i.e. 12) and that the difference would be a noticeable improvement. I am in no hurry to do this, but also do not want to miss out if I can make the recording quality of this guitar that much better. So a few questions:

1) Is the stock pickup on my guitar a Chinese version and is it not as good as the American version?
2) What's the difference?
3) Is the 12 pole version better and why?
4) Would you be in a hurry to change this pickup, and if yes, what are some of the choices you would consider?
5) I have looked at a few other options like the Benedetto and the Bartolini (and others) but some of them do not mount on the pickguard. I would only want pickup options that mount (glued) to the pickguard like the stock pickup is.
6) Lastly, I have read that some of the KA pickups in the USA are not the "better" handmade versions. How do I ensure that it is the better version and and where can you purchase them from to make certain?

Much appreciated
Tim

[Cincy2]

I can't answer all the questions but can give you some pertinent information.

1. Yes. "Good" is a subjective term. To my ears, it does not have the thick, syrupy tone of the KA hand wound 12 pole replacement
2 and 3. See above
4. I only considered the handwound KA
6. This is what you are looking for:

Kent Armstrong® Handwound Series Side Mount PAF Style 12 Pole Humbucker Pickup Black

Cincy

[stevus]

My Eastman AR810 CE had a stock Chinese KA pickup which after about a year I replaced with a KA handwound one. The stock pickup is not bad, so you could wait a while until you know your new guitar and current pickup better. The KA handwound is an improvement and a great match with the Eastman guitar. The only serious alternative I considered was a Häussel Jazz, but that one was a little more expensive and may be more difficult to get in the US. So I don't think you can go wrong if you decide for the KA handwound. I am pretty sure you will be happy with it.

[TH]

Everyone has a different standard of what makes their guitar come close to their ideal. Personally, I have never liked the stock Eastman (Asian Armstrong) pickups but I do have very specific ideas of what I need. I play those Eastman guitars and I love the subtlety, nuance and wood-like attack and decay. I play fingers and use half rounds into a Princeton II. On the Eastman, the Benedetto S6 is the only pickup I feel good with and I changed that out the first week I had my Eastman. That's me, but don't overlook this option when you're shopping around. To my ear, it's the pickup that accentuates the best qualities of the acoustic sound of the instrument and it holds up really well in small group situations.

Good luck
David

[Gitpicker]

Another option is upgrading to the pickup that Eastman now uses, which is a Lollar Johnny Smith. Big step up from the Asian KA pickup and will be a very easy swap. Eastman now uses that in both the 905CE as well as 680CE Frank Vignola model.

[Cunamara]

Go direct to the source, talk to Kent (use the phone number). Tell him what kind of tone you want and he'll put it together for you. And the price will IMHO be very ressonable.

Guitar pickups - Handmade pickups by Kent Armstrong