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You may try to use additional resistor in range between 220-470k. Higher values would tend the amp to get too loud and fizzy. Still You might consider 250K linear pot in place of R62... Regards, Andy :)

According to the schem, in T position You have bare 100K nfb resistor in circuit. I had an subjective impression that removing C40 changed slightly T voicing too, but I tested it for a short time, as I have a pot in place of L R62 resistor and both Excursions are set to L in my amp. That is how...

Depends what You're after. But all-around mod for everyone - besides the tone caps what is IMO essential - is removing C40 Excursion cap and changing dirty Treble pot to linear. For most users not fully satisfied with their XTC's tone those mods would be enough to be totally happy. It really...

Not anymore. Marvel is busy making his own amps, lots of orders on bench now. But the mod isn't anything special actually, if You're familiar with solder iron You may make it for Yourself. You don't even need a board for the mod, You may simply solder resistors paralleled by a caps directly to...

Yes, it will work. We did similar mod with Marvel once, for testing purposes with C2 Structure cap. It works similar to spdt/dpdt switch, but You have more options. But back then we finally ended up with this :) Regards, Andy :)

Excursion circuit is somehow modded in 20th Ann. but I don't know which way. 470pf C40 cap, alongside with audio treble pot, are mainly responsible for "blanket effect" in 101B. Getting rid of C40, alongside with changing dirty Treble pot to linear, was the most important mods in my amp. I...

Thanks guys :). As I've said many times - always a pleasure to help Bogner bros :). That is correct. Every change done to Excursion circuit affects both A & B pots. Yes it was, as the cap removes big amount of highs and mids out of the nfb. Even with C40 if You switch from L to M there a...

In T position the Excursion filter is completely bypassed so You have bare 100k nfb resistor in circuit. In M and L positions it’s added in series with the 100k nfb resistor. So, in stock XTC, in L position you have the 1M//470pF combo in series with 100k, in M position the 220k is added in...

I must admit that I like it very much with my modded amp. Stock it wasn't satysfying, as there was too much compressing lows in the tone. Now my Blue with last stage boosted with .68uF cap truly sounds like hot-rodded JMP - which basically my Blue channel became after the mods done to 2nd gain...

Remove that C40 sucker and You'll never want to have it back in the amp. Don't even test the tone with and without the cap. I should have start with this mod before I modded anything else. The amp is now truly open, very in-front and aggressive as hell. After You remove C40, Excursion circuit...

Modding is more than addiction, it's like bad habit :). Further mods done in Marvel Amps HQ: :) - raised back 1st CC to 4.4nF, soldering 2.2nF cap in parallel with present 2.2nF. The sound became a bit more beefy, not losing clarity. 2.2nF sounded too dry - installed modified PTP Marvel Mod...

Tried Grennbacks yesterday with my modded XTC. They sounded great. It was my first time with Greenies and I must admit that I am still impressed with that creamy liquid sound. Low wattage could be a problem here, had to switch the amp to 50W to be safe. But it still sounded massive. Greenies...

Yes, it is safe. Use Series Mode and Master Volume to set the amount of boost. Regards, Andy :)

No, it isn't. You may footswitchably drop a gain only with boost. Regards, Andy

Did the same once but that's one of the mods that was reversed. The amp was prone to go squealing very fast. I was hitting the chord and instead of sounding it was turning into squeal very quickly. Went back to 1000pf and the problem was gone. But that symptom was caused by other mods, which...

Yes, You got to raise the board to replace the pot. It isn't tough operation and it is really worth doing that. The amp responses much much faster. To do so You got to remove preamp tubes, then remove knobs, unscrew the pots, then unscrew the pcb, disconnect loop wire and desolder wires that...

Keep trying and feel free to ask any questions :) To me it totally kills poweramp's clarity and dynamics. The amp's response becomes totally sluggish. I have it on switch now and can compare the tone with and without the cap. The difference is like night and day. The switch is still there only...

Mojo caps really made my tone. It is definitely more crunchy and smooth now, less "hi-fi". IMO not possible without cutting the traces on pcb to separate it off the Structure circuit. Regards, Andy :)

Before modding my amp I also liked Red Channel without post2004 gain mod, with bare 10k in 3rd stage cathode. But now I need to boost the overall gain a little, as I lowered the bias - therefore the gain - in 1st and 2nd stage. But still "Factory" mod is too much, especially as far as...

Before I modded the amp I have found that the most open tone in Red is with the gain around 10 o'clock (Structure H, I have never used L). The more the Red Gain was turned up the more compressed the sound have become. Now, after modding 1st & 2nd gain stage, where by rasing cathodes resistance...