the4thlast1
Well-known member
Anyone have one of those Marvel mods on a switch they used to sell online. There was someone making them several years ago. Maybe someone on here has an extra one they might want to sell me for My 101b ? Chop chop lol
Bogner Marvel Mod Anyone ?
- Thread starter the4thlast1
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the4thlast1
Well-known member
Anyone know what components are needed
_actual time_
Member
The guy who was making them was named Marvel. 
It was a 3-position switch wired across R12, cathode bypass on the gain stage that's only used on the Red channel. The three settings were stock post-2004 XTC Red gain, stock pre-2004 XTC Red gain, and a Cameron mod on the Red gain.
(In 2004, Bogner changed their factory stock wiring for the XTC Red channel and added cathode bypass on this gain stage, for higher Red gain. The Marvel mod put that cathode bypass components on a switch, so you could switch between stock pre-2004 normal Red gain and stock post-2004 higher Red gain, plus a Cameron higher Red gain mod.)
The difference between pre-2004 lower Red gain and post-2004 higher Red gain was not subtle, on my 101B; it was a lot. I too thought the pre-2004 normal gain sounded better. The difference between post-2004 higher Red gain and Cameron higher Red gain was subtle; the Cameron was squishier IIRC.
The components were a cap and resistor in series, across R12. IIRC the Bogner post-2004 higher gain is 2.7k resistor + 0.22 uF cap; the Cameron is 10k resistor + 1.0 uF cap. Some folks experimented with other values, like 10k + 0.68 uF. The Bogner sub-forum here may have some old posts, but most of the posting I saw about it was on the old Bogner forums, which are gone.
There's a couple tricks that make the wiring of it slick, like connect the caps end of the mod components to the ground end of R12, so the caps are always grounded and won't build up charge and cause popping when the mod is switched on. Wired like that, you can use a SP switch and don't need a DP switch. No need to use shielded wire; it's all going to ground. Etc.
Some folks, like me, also experimented with cathode bypass on R19, which affects Blue and Red, and on the first gain stage, which is the Structure circuit, to use values there like the XTC Classic used. They were all slightly different gain levels and brightness, but IMO stock plus cranking the Treble to 3 o'clock or higher (it's a log pot) got the sound in the same ballpark. It's a dial-with-your-ears-not-your-eyes amp, and the much-complained 101B blanket-over-speakers or won't-cut-through sound is probably people setting the Treble to noon, which = Treble at 9 o'clock on a Marshall because in the 101B the pot is a log pot. You have to crank the 101B Treble to 3 o'clock or higher to = Marshall Treble on noon.
If you use the unboosted Blue and Red much, a must-do 101B mod IMO is clipping C224 IIRC, a 1000 pF cap that is only used on unboosted Blue and Red. It dulls the sound and takes away brightness. It can be added back to the circuit by soldering it across R66 IIRC. I made a unboosted Bright mod mod on my 101B with that cap switchable.
It was a 3-position switch wired across R12, cathode bypass on the gain stage that's only used on the Red channel. The three settings were stock post-2004 XTC Red gain, stock pre-2004 XTC Red gain, and a Cameron mod on the Red gain.
(In 2004, Bogner changed their factory stock wiring for the XTC Red channel and added cathode bypass on this gain stage, for higher Red gain. The Marvel mod put that cathode bypass components on a switch, so you could switch between stock pre-2004 normal Red gain and stock post-2004 higher Red gain, plus a Cameron higher Red gain mod.)
The difference between pre-2004 lower Red gain and post-2004 higher Red gain was not subtle, on my 101B; it was a lot. I too thought the pre-2004 normal gain sounded better. The difference between post-2004 higher Red gain and Cameron higher Red gain was subtle; the Cameron was squishier IIRC.
The components were a cap and resistor in series, across R12. IIRC the Bogner post-2004 higher gain is 2.7k resistor + 0.22 uF cap; the Cameron is 10k resistor + 1.0 uF cap. Some folks experimented with other values, like 10k + 0.68 uF. The Bogner sub-forum here may have some old posts, but most of the posting I saw about it was on the old Bogner forums, which are gone.
There's a couple tricks that make the wiring of it slick, like connect the caps end of the mod components to the ground end of R12, so the caps are always grounded and won't build up charge and cause popping when the mod is switched on. Wired like that, you can use a SP switch and don't need a DP switch. No need to use shielded wire; it's all going to ground. Etc.
Some folks, like me, also experimented with cathode bypass on R19, which affects Blue and Red, and on the first gain stage, which is the Structure circuit, to use values there like the XTC Classic used. They were all slightly different gain levels and brightness, but IMO stock plus cranking the Treble to 3 o'clock or higher (it's a log pot) got the sound in the same ballpark. It's a dial-with-your-ears-not-your-eyes amp, and the much-complained 101B blanket-over-speakers or won't-cut-through sound is probably people setting the Treble to noon, which = Treble at 9 o'clock on a Marshall because in the 101B the pot is a log pot. You have to crank the 101B Treble to 3 o'clock or higher to = Marshall Treble on noon.
If you use the unboosted Blue and Red much, a must-do 101B mod IMO is clipping C224 IIRC, a 1000 pF cap that is only used on unboosted Blue and Red. It dulls the sound and takes away brightness. It can be added back to the circuit by soldering it across R66 IIRC. I made a unboosted Bright mod mod on my 101B with that cap switchable.
Last edited:
Racerxrated
Well-known member
Wow, great info! ^^^
the4thlast1
Well-known member
..The guy who was making them was named Marvel.
It was a 3-position switch wired across R12, cathode bypass on the gain stage that's only used on the Red channel. The three settings were stock post-2004 XTC Red gain, stock pre-2004 XTC Red gain, and a Cameron mod on the Red gain.
(In 2004, Bogner changed their factory stock wiring for the XTC Red channel and added cathode bypass on this gain stage, for higher Red gain. The Marvel mod put that cathode bypass components on a switch, so you could switch between stock pre-2004 normal Red gain and stock post-2004 higher Red gain, plus a Cameron higher Red gain mod.)
The difference between pre-2004 lower Red gain and post-2004 higher Red gain was not subtle, on my 101B; it was a lot. I too thought the pre-2004 normal gain sounded better. The difference between post-2004 higher Red gain and Cameron higher Red gain was subtle; the Cameron was squishier IIRC.
The components were a cap and resistor in series, across R12. IIRC the Bogner post-2004 higher gain is 2.7k resistor + 0.22 uF cap; the Cameron is 10k resistor + 1.0 uF cap. Some folks experimented with other values, like 10k + 0.68 uF. The Bogner sub-forum here may have some old posts, but most of the posting I saw about it was on the old Bogner forums, which are gone.
There's a couple tricks that make the wiring of it slick, like connect the caps end of the mod components to the ground end of R12, so the caps are always grounded and won't build up charge and cause popping when the mod is switched on. Wired like that, you can use a SP switch and don't need a DP switch. No need to use shielded wire; it's all going to ground. Etc.
Some folks, like me, also experimented with cathode bypass on R19, which affects Blue and Red, and on the first gain stage, which is the Structure circuit, to use values there like the XTC Classic used. They were all slightly different gain levels and brightness, but IMO stock plus cranking the Treble to 3 o'clock or higher (it's a log pot) got the sound in the same ballpark. It's a dial-with-your-ears-not-your-eyes amp, and the much-complained 101B blanket-over-speakers or won't-cut-through sound is probably people setting the Treble to noon, which = Treble at 9 o'clock on a Marshall because in the 101B the pot is a log pot. You have to crank the 101B Treble to 3 o'clock or higher to = Marshall Treble on noon.
If you use the unboosted Blue and Red much, a must-do 101B mod IMO is clipping C224 IIRC, a 1000 pF cap that is only used on unboosted Blue and Red. It dulls the sound and takes away brightness. It can be added back to the circuit by soldering it across R66 IIRC. I made a unboosted Bright mod mod on my 101B with that cap switchable.
Wow , thanks dude..This is very helpful !
My 101b is an older one , #32 with the Mercury Magnetics. I got it recently from the original owner, its a time machine in like new condition. Anyways it sounds incredible I honestly dont think it needs anything. It doesn't need more gain but Ive read that the Cameron mod gives a bit of an upper mid push to the tone which I thought might be cool to have on a switch. I dont really "need" it as the amp sounds killer stock.
..
_actual time_
Member
Thanks! I got it all here in the Bogner sub-forum or on the Bogner forums, from folks like Setneck, so I'm happy to pay it back. There's old posts from me and Setneck in the Bogner sub-forum here.