Xtc 101b clean channel boost?

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jamme61
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Xtc 101b clean channel boost?

Post by jamme61 »

looking to tweak the clean boost on my xtc 101b. It seems that the clean boost now switches in a 1 meg in series with a 1N cap bypassing the 3 meg resistor,on non boost. Looking for mod suggestions? I like to get a little more crunch out of it when switching on the boost, not just volume. From what I read this is part of the change to the 20th anniversary xtc. Any help thanks.
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Reeltarded
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Re: Xtc 101b clean channel boost?

Post by Reeltarded »

I don't know how they did it in the new amp or the old amp but we have one.

So the boost. You could raise the value of the cap to like 2n2 and drop the 1M to 500k or put a 1M trimmer in at that point and dial in where you really want it, if that is in fact how the boost works. Is this a mixer leg, say the signal side of a divider? Are you sure the boost isn't the 3M with nothing?

Have a schematic of that area? I dunno and I have enough energy to lay here and speculate only this far at the moment. :)

What are you really missing in the boost? Is it more output or more output and a voicing thing?

It might be that bypassing the 1M with a wire throwing that 1000p over the 3M is just right too.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
jamme61
Posts: 212
Joined: Wed Jan 18, 2012 2:20 pm

Re: Xtc 101b clean channel boost?

Post by jamme61 »

Thanks, I like the non boost side, which in the schematic shows the signal going thru a 3 meg resistor with a 10 pf cap in parallel. When in boost mode it shows the signal being allowed to go thru a 1 meg and then (series) into a 1n cap, which flows around the 3 meg // 10 pf cap. Also the 3meg //10pf never gets disconnected (boost on or off)
The boost now adds a lot of volume with a little brighter sound but, no dirt. I'd like to voice it to be a go between crunch sound, between the green channel (clean) and the blue channel on the amp.
I contacted bogner and all they would tell me is if I lower the 1 meg it will pass more signal, I guess that's all they can say. Thanks again for your time on this.
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Reeltarded
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Re: Xtc 101b clean channel boost?

Post by Reeltarded »

Yes, that is my take on it too.

If you want more drive from the boost lower that 1M or jumper a slightly larger cap over the 1M to taste as far as controlling the response.. or a little of both even.

Using a 1M trimmer instead of the resistor allows you to dial in the drive you would like. Instead of that you might use a 680k trimmer with 100k resistor in series to limit the downward adjustment with the highest setting still being just a bit hotter than the stock arrangment.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
jamme61
Posts: 212
Joined: Wed Jan 18, 2012 2:20 pm

Re: Xtc 101b clean channel boost?

Post by jamme61 »

thanks, working on it right now

looks like I'm staying stk, thanks for the time on this.
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