Questions about JTV-89F pickups/volume pot/etc

[magnoliafan]

Hello,

I just got a JTV-89F (refurbished directly from Line6). It is a well-built, solid instrument that plays very well. But as a new owner, have some questions. I've had the JTV-69 since they launched, so the modeling aspects are not new to me. But I've noticed a few things after playing the 89F for a few days that I wanted to ask experienced owners about.

1. The volume control, when used with the magnetic pickups, appears to function like a linear pot rather than a logarithmic pot. I don't get the smooth roll up with increasing gain like the 69. There is an immediate jump in volume at about 3, and anything about 5 sounds the same. Is that the case for this model? Can that be changed? I know this is not your average pot since it controls two things, but...
2. What are the humbucker pickups based on? I'm thinking DiMarzio because they sound very bright and harsh, as well as overly distorted. I'm sure it's a different pickup than the 69, but it's not nearly as pleasing or versatile. I find the tone to be very limiting. Some of the single coil sounds are very nice on a clean patch (as opposed to even a moderate-gain patch).
3. How difficult would it be to change the magnetic pickups? I know people have done it, but the interior of this is a lot more complicated than your average passive pickup guitar. Are the pickup leads soldered or do they use Molex connectors? Are there wiring diagrams anywhere on the web?
4. I am experiencing a couple of quirks related to the Variax part. I am going to check the firmware version tonight and then flash it if it is not up to date. When I switch patches on my Helix, it always turns the modeling "on" whether the patch is set for Variax on or off. Could be a software thing that I need to update, but since I just got this directly from Line6, I will be surprised if it isn't current FW.
5. As I noticed on the 69, palm muting strings with modeling just doesn't work well. Since the 89 is geared towards metal and has all those down-tuning presets, I expected palm muting (which is a big part of rock and metal playing) to work better. I thought I had read that the Shuriken addressed this, so maybe a FW update will help.

 

I am also going to have to turn up the gain levels on the modeling. I remember having to make adjustments on the 69 as well. If I am running both mags and Variax to the Helix with discrete inputs and signal paths for each, the magnetic pickups greatly overpower the modeled sound to the point that you can barely hear them. There's also a noticeable drop-off in volume when I go from mags to modeled on the same signal path and patch. This I think I can handle since I did it before on the 69.

 

I really see this being a useful guitar if I can address a few things!

 

Thanks for your help, folks.

[cruisinon2]

1 hour ago, magnoliafan said:

As I noticed on the 69, palm muting strings with modeling just doesn't work well. Since the 89 is geared towards metal and has all those down-tuning presets, I expected palm muting (which is a big part of rock and metal playing) to work better. I thought I had read that the Shuriken addressed this, so maybe a FW update will help

 

 

The dreaded "piezo plink" is a disease that can afflict all the models. Target demographics don't matter much... the technology is all the same, and unfortunately the shortcomings are what they are. The are numerous contributing factors, many of which you can find discussed at length in an epic years- long thread titled "Do you have the same problem with the 6th string".

 

One big factor is the use of high gain tones... this can really exacerbate the problem. So I'd argue that an 89 owner might be more likely to notice plink issues for that reason alone... at least compared to the guy with a 69 who's playing SRV and Clapton tunes all day long. 

[psarkissian]

1) Mag pot controls are audio taper. 89F is a two pick-up HH configuration,

69 is a three pick-up HSS. Difference in pick-ups, difference in perceived tone and amplitude.

 

2) James Tyler was going for a Duncan like spec.

 

3) Wiring diagrams are on this Forum's Knowledge Base. Third party pick-ups should have a DC/bulk resistance

range of 6k-Ohms to 8k-Ohms, so as to be impedance matched to the rest of the circuitry downstream. Impedance

matching is necessary in guitars like this with active electronics.

 

4) Check the Helix manual, in the edit page of the Helix should be a Variax patch "Force/Don't Force" kind of setting.

It tells the Helix whether or not to "force" the Variax to use the Helix default Variax patch setting.

 

As far as Firmware goes, I'd have to look at the serial number in your account to get a better idea about the Firmware.

Or you could check for certain using Line 6 Monkey. Info on updating Firmware can be found on this Forum's Knowledge Base.

 

5) More info on the subject of klang tone or plink tone is also found on this Forum's Knowledge Base.

 

6) String amplitude on the modeling can be done by adjusting string amplitude levels in Workbench HD .

 

[magnoliafan]

I upgraded the firmware to 2.23, and the volume difference between magnetics and modeled is much better. I may still tweak it some, but it definitely helped. Palm muting also seems to work better, except on the low E, but that may be partly psychological or a subtle change in my technique. Also figured out that not all Helix patches turn modeling on, so I will check to see if that is a Helix setting causing it. 

 

I still think the volume control is not behaving properly. If it should be the same on all JTV guitars, this one definitely behaves differently than my 69.

 

psarkissian, thanks for the detailed reply. Is the bridge humbucker in the 89F the same as the 69? They sound radically different. I was surprised the resistance on the 89F bridge pickup is 6-8k-Ohms, because it seems to be much hotter than that. It's pretty far from the strings and still seems too hot. I might swap it out and see if there is a difference.

 

[magnoliafan]

I found the wiring diagram, but it's really just the wire outs of the pickups. Not very helpful. It doesn't show where inside the guitar they are connected. I'm going to need something more detailed or try and trace the wires if I'm going to try a swap.

 

Also, this shows it as a 5-conductor pickup. That's new to me.

[psarkissian]

Slight difference in the turns ratios in bridge pick-ups between them.

69 and 89F are different guitars, so would expect a difference in sound in mags mode.