psarkissian

@dukeofdream,... oh yeah, right.

" 4 times man and they never replaced his pcb " --- Did you go to an Line 6 authorized service center? I don't see any service record for that. Which service center was it? Knowledge Base posting,...

If it's not the cable, then it's an issue with the photo sensor, it will need to be serviced. https://line6.com/find/service_center/ For the authorized service center in your area.

Don't use the 6L6GC,... forget what the guy from the Tube Store says, he's probably not an expert in hybrid amps like this, so use the specified tubes. I worked on hundreds of these the past 14 years I've been here. The characteristic curves are not close enough to be 100% drop-in swap. These are not all analog Marshal amps. Use the specified tubes. 12AX7's are less crucial, the B's are optimum, but EH's will do,.... just no JJ's. Using 6L6GC or other unspecified tube is an unsupported modification to the amp. If this were to show up on my bench, I might be told to send back untouched. I don't want to see that happen.

Also, it's not the fundamental, but harmonic partials. Altering my palm technique helps me a little. I suck at palm muting.

One at either, depending on how well it was tuned, or whether they were in model mode with Alt Tune on.

The comments I've read put it at 1.6kHz and 1.7kHz.

Make use of EQ and adjust palm muting technique for good coverage on non played strings, so they don't resonate from sympathetic vibrations. It's what I do,... and I suck at palm muting to begin with.

No. And if you could, it wouldn't work on nylon strings,... not enough string tension to piezo contact area pressure. It's why I asked about single or six separate piezos. The 300 Acoustic Nylon, used a single slim bar type piezo, as it is much like a classical guitar bridge bone. And so it requires less string tension to piezo contact area pressure. The separate piezos are designed for our steel string/bronze string guitars.

Is it the 300 with the single strip piezo or the six piezos in a bridge mount?

" 12AX7b (China) and 5881WXT (Soviek, Russian). IS that what I should get? " --- Yes. 5881WXT power tubes have to be a matched set. " Thetubestore.com when I called a few years ago said to use the 6L6CG and the Tung-Sol 12AX7. " --- Yes, but for an "all analog" tube amp. The characteristic curves are close, but not close enough. So the specified tubes have to be used.

Very good.

1) 6L6GC is the wrong tube and therefore, probably the wrong bias. So yes, the fuse would blow. You can't use the same bias on a different tube, even in an all analog tube amp. 2) JJ's are also the wrong tube so the normal bias volts would be the wrong bias volts. 35mV +/- 2mV does not apply to other tubes in this amp. 3) Power tubes have to be matched pairs. 4) These are not all analog tube amps of old, these are hybrids (analog/digital), the two sections need to talk nice to each other. Not using the correct tubes and bias, undoes that. I don't want to see your amp on my repair bench. Use the specified tubes and bias. Please,...

I've done my share of customs and Frankenstein Variax guitars,... it's not easy, and it won't sound the same in another body. Some parts are available out there, some are not. Schematics and other proprietary property is not available to the public. And Line 6 can be tenacious about protecting its intellectual property. Don't go there.

" OK, so they will sound "dark".... is that something that can't be EQ'd out? "--- Maybe, if there is enough upper frequency there to EQ with. Trying to compensate for something that isn't much there would be trying to brute force the EQ,... and that is like putting too much salt on a meal to compensate for a specific flavor. That's a big maybe to put a bet on. " Or, what about adding a 19k resistor in parallel with the pickup.... wouldn't that drop it down to around 8k? " --- Don't go there. Don't go beyond doing just a pick-up swap. It's not just a resistor, there are also other components downstream that will come into play. Don't go there. Remember, this is an active circuit guitar, so it needs to be treated a little differently. Seymour Duncan has a nice selection, some within the 6k to 8k Ohm range, some outside the range. https://www.seymourduncan.com/products/pickups/electric/p90 Give them a call, check those out.