Taylor T5 T5z Switch Problems, Repair, Schematic, Substitution

[jonfields45]

At 9 months of pretty heavy use the position 3 bridge output of my T5z would mute intermittently. Taylor warranty repair offered to clean it, but I paid $100 for them to replace it. 6 months later the new switch is starting down the same path. I went and retrieved the old switch from the warranty center.

I contacted Schaller support and while they confirmed it was their Megaswitch hardware they said they had no involvement with the circuit board. They would offer no advice but did offer to inspect the switch if I sent it to them in Germany (literally a polite no comment to every question). A Schaller Megaswitch is a gorgeous piece of mechanical overdesign.

A classic CRL Strat switch uses a claw contact that is self cleaning and aligning. The Schaller Megaswitch uses a wiper design which requires good planarity between the circuit board and the wiper (thus play in the handle could be bad). Comparing the old and new switches it appeared that the tension screw was getting loose.



The middle position 3 of the switch has the least support from the housing and the play in the lever can be eliminated by tightening that screw. When tight the screw moves with the switch. When loose it is stationary. Stewart Macdonald reports that for the Megaswitches they have in stock, the screw moves with the switch (one of the questions politely declined by Schaller). For my “bad switches” the screw was stationary. I took the spare switch apart and confirmed the main tension screw is probably not thread locked (another question declined by Schaller). The screw can be removed and the switch is still held together by the circuit board (there are AGF postings about the screw rattling loose in a T5).

I performed two experiments.

1) With the spare switch I removed the circuit card and cleaned it with DeoxIT and a cotton swab. After reassembly it worked perfectly with or without the tension screw tightened
(analog volt-ohm meter on the appropriate contacts while wiggling the switch handle in position 3).

2) For the switch in the guitar, I used a 3mm hex key that I hack sawed small enough to fit through the rear circular access to tighten the tension screw until it moved the switch lever. It now also works perfectly. The switch still moves easily even with the screw tightened down very firmly.



In order to remove and service a Taylor T5(z) switch you need to remove the preamp board which blocks access. This is a lot of work to clean a switch. I plan to tighten the screw a little whenever the middle switch position gets problematic. If that stops working, I'll clean the switch, in place, with DeoxIT (careful to surround the switch with tissue to catch overspray). Worst case I will remove the switch and clean as above.

Below you will find a listing on how the summing board and switch work and how to substitute a CRL 5-way Strat switch since its design does not have this alignment problem (or the series pickup option).

Jon

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3 Wire Color & Letter Codes (pickups to summing board & switch to preamp)

BD soundboard sensor
NK neck single coil pickup
HM neck humbucking coil
BR bridge pickup
Red + (+/- chosen arbitrarily)
Black ground
White -

9 Wire Color Code (summing board to switch)

G black ground
6 red BD+
5 brown BD-
4 yellow HM+
3 white NK-
2 green BR+
1 blue BR-

Notes

HM- shorted to NK+ on summing board.
BD+ red shorted to 3 wire + red on switch board

The Following Refer to the 3 Wire Cable from the Switch to the Preamp

5 Way Switch Position 1 (+BD- +HM- +NK- in series, BR+/- shorted to -)

3 wire red BD+
3 wire white NK-, (BR+, BR-)
Notes: HM+ shorted to BD-

5 Way Switch Position 2 (+HM- +NK- in series, BR+/- shorted to -, BD+/- shorted to +)

3 wire red HM+, (BD+, BD-)
3 wire white NK-, (BR+, BR-)

5 Way Switch Position 3 (+BR-, BD+ to +)

3 wire red BR+ (BD+)
3 wire white BR-

5 Way Switch Position 4 (+HM- +NK- in series, parallel with +BR-, BD+/- shorted to +)

3 wire red HM+, BR+, (BD+, BD-)
3 wire white NK-, BR-

5 Way Switch Position 5 (+HM+ +NK- +BR- in series, BD+/- shorted to +)

3 wire red HM+, (BD+, BD-)
3 wire white BR-
Notes: BR+ shorted to NK-

5 Position “Classic Strat” Switch Substitution

Wiring

Strat Neck PU lug: BD+ (9 wire red)
Strat Middle PU lug: BD- & HM+ (9 wire brown and yellow)
Strat Bridge PU lug: BR+ (9 wire green)
Switch output lug: 3 wire red
BR- (9 wire white) & NK- (9 wire blue) to 3 wire white
Switch housing: 9 wire black, 3 wire black

Switch Translation

Strat Neck T5 position 1: acoustic
Strat Neck+Middle T5 position 2: neck
Strat Middle T5 position 2: neck
Strat Middle+Bridge T5 position 4: neck || bridge
Strat Bridge T5 position 3: bridge

Reference Pictures:

[jonfields45]

At yesterday's rehearsal, 10 weeks and a few days from tightening that tension screw, the guitar muted when switched to position 3... I opened it up today and that tension screw was quite loose. I noticed that at points where I had it tightened, but not quite tight enough to consistently follow the switch, it only moved in the direction that loosens it :~(. This is my main gigging and rehearsing instrument and tightening that screw every 10 weeks or so seems unreasonable to me. I guess I'll contact Taylor for some ideas. I'll post what they have to say.

EDIT: Just tighten the screw very firmly. The switch still moves fine and the screw takes longer to come loose.

[jonfields45]

Poking around Stew-Mac there is one review out of maybe 40 that reports the same problem. I think most guitars are not played very often, which would make this kind of problem relatively uncommon and certainly not something that will come up during the honeymoon where most reviews are written...


3.0
Great idea, bad design
By Robb Lowe from Spartanburg SC
(Customer's Reviews) Monday, April 08, 2013

The idea of the switch is great. The build quality is not. I've been through 3 of these things in 2 years. The center screw comes loose and once it backs off to a certain place, there's no saving it. Why did they not splay this at the factory? It would be a simple fix. If you need Tele tones on your Strat, this is great. But be prepared to pull your pickguard at least once every 6 months to make sure the switch lives another 6 months. Even though I loved what it did, I couldn't handle it dying in the middle of a gig again, and went back to a standard CRL 5-way.

[jonfields45]

In the absence of quick feedback from Taylor and a gig tonight... I lubricated the spring washer with teflon grease and torqued down that tension screw hard. The switch housing is designed such that the tension screw all the way down does not freeze the switch from moving; something I previously misunderstood. The switch works normally and hopefully the screw won't work itself loose any time soon. The next step might be rubber fortified cyanoacrylate to lock the screw into the threads of the handle.

[Ned Milburn]

Maybe some locktite...??

[jonfields45]

Originally Posted by Ned Milburn

Maybe some locktite...??

I was thinking the shock resistant rubberized superglue gel might be a better choice (the one I have is Loctite branded), but I would still like to hear from Taylor. At this point I've got two T5 switches (along with a collection of CRL and Oak Grigsby in my parts box for a more radical fix...maybe the world's first T3z since I never use the parallel or series PU options) and no mistake would be catastrophic.

I am certain that almost no one plays a T5 as a primary electric guitar. If they did my problem would not be news.

[SLG]

The best solution is to apply a small amount of Loctite 242 (blue) to the thread. This would prevent the chance you over torque the screw and damage the threads, but would prevent the screw from loosening from use.

[jonfields45]

Originally Posted by SLG

The best solution is to apply a small amount of Loctite 242 (blue) to the thread. This would prevent the chance you over torque the screw and damage the threads, but would prevent the screw from loosening from use.

That seems to be the right product. Assuming no better instructions from Taylor, I'll use that next time it fails.

The screw is magnetic (plated steel?) and the handle might be stainless steel, so I was thinking it could take a fair amount of torque without stripping. I did this work with the switch in the guitar, so clearly I could not really go too crazy with torque. My repair of 10 weeks ago only torqued the screw enough to move the handle and even that lasted a few months.

I do very much appreciate the feedback!!!

[jonfields45]

Taylor offered to replace the switch today and confirmed there is no redesign in the works. My electronics warranty runs out April next year and I've got to decide whether to go with a third new switch, or stick with my torque to be followed by threadlock plan. I did ask if they would extend the replacement offer an extra year to see how I make out first. [edit: got an email right back agreeing]

[jonfields45]

Since tightening the screw with some force I've gone 6 months trouble free which is probably record with margin for my usage. If it comes loose again I'll add some threadlock. Schaller has redesigned the Megaswitch with riveted stamped steel.

http://www.stewmac.com/Pickups_and_E...egaswitch.html

I bought one hoping it might be compatible with the circuit boards for the older cast design but it is not (at minimum the two screws attaching the PCB are a couple of millimeters further apart for the new design).

My latest problem is I've worn out the volume control (Alpha 9mm rotary pot 9, 3RP/0912N, shaft C, Style D1, B linear taper with center detent, 10K ohms, 10K turn lifetime rating). Not surprisingly no electronics distributor carries it. Taylor kindly sent me a refurb preamp board so I'm back in business, but I would like to repair my original board and don't want to wear out my welcome at Taylor... Maybe a repair center can order them??? A friend's ES1.0 3 volt system also needs a new volume pot (similar except for the specifics of the PCB mount) and I would like to get my hands on a few of those too.

[jonfields45]

The 9mm pots Taylor uses turns out to be a relatively common standard. I was able to find ALPS pots online (Mouser) that with a little work to shorten the shaft will be an otherwise perfect fit. I ordered 12 of the ALPS (RK09L114001T) and 6 Bourns (probably not the best choice since it lacks threads) from Mouser for a cost of about $1 each. When I figure out which is the best fit I'll report back. I suspect the inventory at all the major electronics supply outlets (Mouser, Newark, etc.) varies and where I went off track was looking for Alpha only, for what is a standard form factor with multiple sources.

[jonfields45]

This is the pot I think Taylor's subcon uses on the T5 preamp:



Given the regular acoustic Taylors use the same supplier, same value, and same mounting hardware (knobs, ferrules, standoffs), then this is the likely pot on those boards:



These are called 9mm snap mount pots by the major manufacturers. There are literally millions of manufacturing options with a minimum order of 500 pieces which means it is impossible to find this exact part in-stock at any electronics supplier. This was the closest I could find and the following photos document how I used a 1" belt sander to make it fit. It is an ALPS RK09L114001T (Mouser 688-RK09L114001T) which Mouser carries with a significant amount of stock (presumably means it is a standard stock item for them).

http://www.mouser.com/ProductDetail/...2fUuGzyQCQw%3d




This part has a metal shaft and a 50% higher turn lifetime. I have not tried to mount it in my guitar and you can see the threads for the ferrule are definitely higher, but I don't think that will be a problem. I ended up belt sanding a little more off the shaft after soldering it down. Most of my engineering background is in management and my personal soldering skills date back to tube Heathkits and point-to-point guitar and amp wiring. This is a very high quality board with minimum dimension plated through holes. I found to remove the original pot I had to clip off the leads and snap pins, remove the remaining pieces with my soldering iron, and then vacuum out the remaining solder (that last step was harder than I anticipated). I used what turned out to be useless Bourns pots to test the holes to make sure they were clean enough (and destroyed one pot). In spite of that I had to compress the leads of the ALPS pots with long nose pliers to get them to go through.

And now for my rant! Electric guitarists are constantly tweaking their volume controls. Do it every other song on your main guitar and you will blow through the 10K turn lifetime pretty quickly (10K turns is a pretty typical spec for even the large pots in your Strat). The T5 pot is impossible to find and difficult to replace. In general I'm not a fan of PCB mounted pots in electric guitars. I have a friend who's 3 volt ES-1.0 needs a new volume pot and he won't have the ability to get a refurb preamp card. So far I've not found an obvious replacement anywhere for that pot (I could look harder...).

Taylor support was FANTASTIC (THANK YOU CHRIS BEARDEN!!!) and my only gripe is with the design decision to PCB mount hard to source pots in an electric guitar.

[jonfields45]

I took these two pictures to show that the ALPS pot with the longer threaded extension is compatible with the Taylor mounting ferrule.



Ignoring the hand work to shorten the pot shaft, I think the ALPS pot should be a better solution; 15K turn lifetime (10K for the original Alpha), metal shaft, and longer shaft support.

[dragonfly66]

Thanks for the info. No problems for me yet, but good to know the research has been done just in case.

[jonfields45]

I'm now at 9 months since torquing down the switch screw with no problems.

I did buy a solder vacuum and found a reasonable substitute for Taylor acoustic ES pots:

http://www.acousticguitarforum.com/f...d.php?t=434625

If the T5z preamp dies again I might just get rid of it. I've built a compatible preamp card on a small breadboard using these components and a hand wired full sized POT (no tone controls since I have mine poster taped at the detent). Between the four dual opamps and LED the Taylor preamp draws roughly 20 mA which translates to roughly 25 hours lifetime for an alkaline 9v battery. The no EQ Bartolini is rated 1500 hours for a single 9v battery and would easily support annual battery replacement. I recently discovered 100K turn lifetime full sized POTs and might hunt one of them down for this project... [EDIT: checked the lifetime on the Bourns pots I already ordered and they are 200K turns, which is 20 times better than the PCB mount pots Taylor chose for this preamp board!!!]

http://www.musiciansfriend.com/onboa...&CJPID=5696037

http://www.molex.com/molex/products/...CB_HEADERS.xml

http://www.molex.com/molex/products/...CB_HEADERS.xml

http://www.molex.com/molex/products/...CB_HEADERS.xml