Markfothebeast

So the Pod XT Pro Live cannot control the amp like the FBV Express? The FBV Express MKII manual states that it can be used with this POD. I don't understand how that works. What's the purpose of plugging a pedal in to a pedal?

I recently acquired a Line 6 Pod XT Live Pro effects pedal. Will this function via the "Variax" port with the Line 6 Bogner Spider Valve MK1 amp and work in place of the FBV foot pedal?

I had a similar issue on a bass amp. It was a solder joint to a pot. The heat of the tubes below like to melt solder on combo amps that are poorly vented.

Just an update on this amp. It's been about 4 months running the JJ tubes I was told not to use. I play the amp for 4 hour performances and 3 hour practices twice a week. The amp has not had any type of issues. Having the fans vent the head unit keeps it cool to the touch and is most likely extending the life of the circuit boards and components. I am still very happy with the sound of the tubes on stage.

Can you explain why you cannot run JJ or Tung-SOL tubes? The service manual does not say this. It also does not state to use only Electro-Voice or Sovtek brand tubes. My MKI came with Sovtek 5881/6L6WGC power tubes. But not saying you should do what I did and run JJ 6L6GC's/Tung-SOL 12AX7s and make your amp sound totally awesome. They have different max wattage and voltage ratings. Perhaps the filament is larger and generates too much heat? I'm now curious as to why.

I changed the tubes today. I did not use the suggested tubes in the admin post. The service manual states to use 6L6 tubes. It did not specify WGC/GC/WG and so on. It simply stated 6L6 tubes. I needed tubes by Saturday so I had to purchase them locally. Words cannot describe how drastically the sound quality has improved. I've installed "JJ 6L6GC" power tubes and Tong-Sol 12AX7 Pre-Amp tubes. Not even the same amp anymore... It doesn't even seem like I'm playing the same guitar. The 6L6GC tubes are physically longer. I simply had to stretch the springs on the tube brackets about 3/8". These tubes also have a higher max wattage and voltage rating. I'm not sure if that will increase the life expectancy or not. But WOW! I should've installed these a long time ago.

I wired up two 12v DC fans to a 1200mA power supply. One fan sucks in cool air and the other blows it out. Works like a charm. However, I think it's time for new tubes as mentioned. I don't get a very heavy tone like the solid state Spider III 75 I just picked up. It's as if the sound is temperamental. It might have a nice, heavy tone one day and another day sound like a wet fart. Even after I raised the bias voltage to 34mV.

I have the same issue. I go through and reprogram A, B, C, and D with the channel volume knob vertically centered. The volumes still largely vary. The distortion channels have more output than the clean. So than I have to do it again and again. And standing next to the amp to turn reprogram doesn't help... So when I crank it up and it's mic'ed at a gig the variables in each channel volume become much more obvious. You almost need a decibal meter to get it right. I believe there's an Android app but I don't know if it's accurate.

If you plan to repair, I think I have one of these amps out in the garage in pieces. The input jack failed and umm, the circuit board is not one to solder. It's some type of laminated board that isn't very solder iron friendly. The copper is so thin it's nearly impossible to apply enough heat without burning through. So it's now a boat anchor.

I own the same beast. Last resort, throw the two boards in an oven sitting perfectly FLAT, and cook it at 250ish to "re-flow" the solder joints. This is if the solder perhaps is at fault if the amp heated up enough to cause a poor solder joint. These amps get crazy hot because the chassis is sealed. Seen it happen many times to electronics and even solid state amps. Somehow I have doubts that the chip itself actually failed. The ABS plastic and ribbons would need to be covered with an insulating material. I did this a few times as a quick fix on other electronics as shown here:

Ahh. The circuit disclosure. Hehehe. Anyway I've read that the Spider Valve MKI is not accessible to edit. It appears true if there's no firmware update available. So it must not be linked through the CAT5E/USB. That's too bad. I was really looking forward to that feature.

I'm a little disappointed that it's inaccessible via MKII Express to edit the pre-sets. Is the chip a ROM?

Anyway, I went through and played like I typically do through the Spider Valve. Amp keeps a stable sound, as should be. I'd always thought my mind was playing with me when sound levels and effects were unstable. Still playing through the amp right now. No issues. FYI, I recorded the entire scenario for YouTube. But I have yet to determine that everything is still 100% stable. Temps are cool to the touch on the chassis.

After about 45 min, it kept slowly creeping up. When it was hot I brought it to 34mV. It went up to 35mV. I came back home from band practice and had zero issues after installing two 12v fans to cool the PCBs. It was as cool as a cucumber and did not pull any odd sound changes on me. The sound had always seemed to erratically change as far as distortion/clean. It operated just fine now.

V3 reads 32.7mV and V4 reads 33.2mV. Think I should raise it? Service manual says +/- 2mV. This is after about 1 minute and the reading is steady.

For the 1.5 hour drive to the nearest authorized Line 6 tech, the fuel, and service costs, I could purchase another one of these amps used. In a few minutes I'm going to do a check up on the bias voltage to ensure that it's within range. There seems to be a lot of numbers flying around as far as the temperature of tubes. The infrared thermometer is probably not the most accurate device when pointing at glass or metallic objects. The innards of the tube could be reading these temps. The inside of the tube is probably far hotter than 350F.

Everything I've managed to gather has basically concluded that this model amp is flawed from the start. The amount of heat rising upward from the tubes directly in to the sealed enclosure is decimating the components. My conclusion comes from any and all tube amps that are designed with the tubes below. But stupidly enough, there's not an ounce of air flow in to this amp.

Okay, so I won't be using AC fans. Apparently the brushes create electrical noise. Plan B. DC fans with a power supply hard wired in to the power input.

I can discharge the caps. How does the "bias" voltage change? Do new tubes have lesser resistance and the voltage increases?

Oh geez... That's an easy procedure. I had to look that one up. A simple voltage adjustment. I can handle that in my sleep. I should give it a check. Maybe someone had swapped in tubes without voltage adjustment. Looks like 35mV. I'll have to find the correct voltage for my model amp. Is there a service manual available?

May I ask, what's dangerous about tubes? Do they hold capacitance? I've never changed out tubes but I do understand that they require a "Bias". Is that a different procedure on Line 6 amps vs a standard tube amp?

I can't see the entire model right now other than "6L6WGC Sovtek, Made in Russia".

Here's what's in it now for tubes.

Thanks! The names of the Line 6 products are confusing. The manual shows a photo of it and states it's MKII. But that must be incorrect.

Here's a similar issue on a bass amp with a pot. It had several symptoms from a single pot.