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Peacocke

Weird model knob activity

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I have a 2011 JTV59 that I bought second-hand at the beginning of this year. The model knob wasn't working, so I got it cheap. I figured that, if I was lucky, it would be a simple matter of padding out the inside of the knob to raise it enough to work. Unfortunately, it turned out that it wasn't that simple. I left it for months and then finally decided to do something about it recently. I bought a couple of Belton BTDS20HPT encoders, dismantled the original PCB-encoder assembly and attached the new encoder. Hey presto! It works. At least, it works from Custom 1 to Chime, at which point it stays on Chime instead of moving to Semi and then goes back to Custom 1 again. I've reflashed it, but it's still doing the same thing. Does anyone have any idea what might be wrong? I'd like to see this guitar up and working properly. I already had a JTV69 and bought the 59 in the hope of being able to save it from the scrapheap, which I guess I have done in part, but it's frustrating that it doesn't want to play ball.

 

Thanks for reading and thanks in advance for any suggestions.

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Are you sure that's the right encoder to use?  The model selector has 12 positions but that BTDS20HPT seems to come in 8 10 16 18 24 32 40 position variations (not 12). Sounds like maybe you got one that is 8 or 10 position? I can't remember for sure but I believe there is a physical stop on the knob that blocks multiple positions so maybe a 16 position is right?

 

It also looks like you can get that encoder with BINARY, BCD, or GRAY encoding. Not sure which the JTV is expecting.

 

Mark

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Thanks for the reply. I did wonder if it might be something like that. I suppose I could always give in and buy the original parts, but they’re a lot pricier than the encoders I bought. I thought there were the same number of positions but I’ll check.

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I don't really know if it could be applicable and work also for the JTV, but here follows the procedure to calibrate the Model Select Knob of the 500/700 (but it requires the Line 6 XPS box and a TRS cable)

 

(taken from the "Variax Troubleshooting Tips" post)

 

Q: How do I calibrate the Model Select knob on the Variax 500/700?

A: Here are the instructions on how to calibrate the Model Select knob on the Variax 500/700:

 

*Please make sure that the output from the Variax 500/700 is plugged into an amplifier or monitoring source to hear the audio beeps from the guitar.

 

1. Unplug RJ45 cable from guitar.

2. Turn off Power (disconnect "¼" TRS cable from guitar).

3. Turn the volume up.

4. Pull model selector knob "up" and away from the guitar body and set it to position Custom 1.

5. Set pickup selector to 4th (neck-middle) position.

6. Set tone knob to middle position.

7. Turn on power (connect "¼" TRS cable to guitar).

ONCE INITIALIZED, YOU WILL HAVE APPROX. 13 SECONDS TO COMPLETE THE FOLLOWING PROCEDURE:

8. Turn tone control to min and then max.

9. You will now hear a beep sequence come from the amp or monitor source the Variax is plugged into. (The beeps will NOT come from inside the guitar itself.)

10. Turn model selector from "Custom 1" through all positions up to "Custom 2" this should be timed to approximately 1 second per physical step. (Counting: "one, one thousand", making sure to turn the pot on the one).

11. You will hear a low-high-low beep when completed.

12. Model selector will now be calibrated.

13. Press the Model Select knob back in to the guitar body to the "down" position.

If you hear the low-high-low beep prior to completing the entire rotation of the model select knob, unplug the "¼" TRS cable from guitar and start over again until the timing is correct.

 

____________________________

 

however in case of need the following spare Model Select encoders from Line6 are not too expensive, description says that they are for the 300/JTV-69, but I strongly suspect that they work fine also on the other JTVs.

 

257346.jpg

$ 9 - Line 6 24-12-0016 Model Select Encoder

 

336829.jpg

$ 12.50 - Line 6 50-02-0090 Model Select Encoder+assembly

 

 

_______________________________________________________________________________________________________________________________________________________________________

All about POD HD500/X

help and useful tips

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Thanks for that. I’ll give it a go. I have a TRS cable and XPS box from my 700 Acoustic. I would have been very happy to pay $12.50 for an original encoder but Fullcompass don’t ship to the UK, where I am. I can buy it from Yamaha here, but it costs $69. The full harness costs $131, so you can see why I bought a couple of encoders from China for $12 in the hope that it would be an easy fix.

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2 hours ago, Peacocke said:

Thanks for that. I’ll give it a go. I have a TRS cable and XPS box from my 700 Acoustic. I would have been very happy to pay $12.50 for an original encoder but Fullcompass don’t ship to the UK, where I am. I can buy it from Yamaha here, but it costs $69. The full harness costs $131, so you can see why I bought a couple of encoders from China for $12 in the hope that it would be an easy fix.

 

I see. If I had the same issue I would have done the same as you, since I live in Italy.
However, I think you bought already the right encoder model, and I believe it's the same one mounted on different (not all) Variaxes.

 

photo_1475826220.jpg

BTDS20HPT SERIES (DIGITAL SWITCHES)

 

Suitable for setting code with push-on switch
Detent number from 8 to 40 are available

(Rotational torque can be changeable by option
Push-on torque can be changeable by option)

 

BTDS20HPT specs.pdf

 

_______________________________________________________________________________________________________________________________________________________________________

All about POD HD500/X

help and useful tips

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"It also looks like you can get that encoder with BINARY, BCD, or GRAY encoding. Not sure which the JTV is expecting. "---

Don't go there. Each guitar board is programmed for the model type it goes into. Don't try anything custom. Use the correct part.

 

@hurghanico, old Variax calibration doesn't apply, JTV is a different kind of cat, have to cuddle it under the chin differently.

 

@Peacocke, see my mate Mark Wright at Mark Wright Music in Northampton. He was my counterpart at Line 6 UK when we

had a location in Rugby. He still service Line6 gear and knows this stuff as well as I do.

 

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Thanks. I was in touch with Mark many months ago when I first got the guitar. I’ll give him another call now that I know that the board is working and that it’s likely to be nothing more than the switch. As you say, the calibration didn’t work on this model. 

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Old Variax used a pot instead of an encoder, hence the need for calibration an that.

Not relevant with JTV, Standard and Shuriken since they use encoders, and so no calibration needed.

 

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56 minutes ago, psarkissian said:

Old Variax used a pot instead of and encoder, hence the need for calibration an that.

 

On Fullcompass website they wrote that the encoders I linked in my previous posts in this thread are for Variax 300 and JTV-69.

So based on what you said above here about the Old Variax, should I infer that they gave wrong information about those spare parts?

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No.

The posting of the Knowledge Base is correct for the 500 and 700.

Newer JTV, Standard and Shuriken are different.

 

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16 hours ago, hurghanico said:

On Fullcompass website they wrote that the encoders I linked in my previous posts in this thread are for Variax 300 and JTV-69.

 

34 minutes ago, psarkissian said:

The posting of the Knowledge Base is correct for the 500 and 700.

 

So even if the Variax 300 belongs to the older generation such as the 500/700 (which don't use encoders), however it is using an encoder instead of a pot for the selection of models, the same encoder mounted on the JTV-69, right?

So the Fullcompass info about that specific encoder are correct, right?

 

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300 and 600 use a different and earlier encoder than the ones used in this newer generation of guitars.

The 500 and 700 the only two models to use the pot, and so may need calibration every now and then.

Current encoders used are probably available on Full Compass, not certain if the earlier ones are still available.

 

 

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" ... however it is using an encoder instead of a pot for the selection of models, the same encoder mounted on the JTV-69, right? "--- the encoder part itself alone,... yes.

The encoder full assembly (50-02-0090),... no, not interchangeable with older Variax.

 

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23 hours ago, psarkissian said:

" ... however it is using an encoder instead of a pot for the selection of models, the same encoder mounted on the JTV-69, right? "--- the encoder part itself alone,... yes.

The encoder full assembly (50-02-0090),... no, not interchangeable with older Variax.

 

 

Ok... Thanks for all the useful info.

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