Xotic - RC Booster

azza1 · Post by **azza1** » 28 Oct 2007, 05:48

Enjoy! More photo's still to come
All diodes are 4148

Goop_buster · Post by **Goop_buster** » 30 Oct 2007, 21:23

Thanks azza
Hey there seem to be a 470 ohm "mojo" CC resistor in there

Is that a stock component or a mod

Interesting to see that the board is a bit different from that in the AC.

Perhaps just another board revision?

madbean · Post by **madbean** » 30 Oct 2007, 21:53

I'm including one mojo resistor in all my builds now. The question is: what's the best place for you mojesistor? Is it in the feedback loop of your TS? Or in the tone control of your Muff? Or on the collector of your pnp germ?

Enlighten me!

Goop_buster · Post by **Goop_buster** » 30 Oct 2007, 22:05

madbean wrote:I'm including one mojo resistor in all my builds now. The question is: what's the best place for you mojesistor? Is it in the feedback loop of your TS? Or in the tone control of your Muff? Or on the collector of your pnp germ?

Enlighten me!

At least we know that Xotics opinion is that the correct place for CC-mojo is in series with the signal before the output. There was a similar CC resistor at the same position in the AC-booster too.

bajaman · Post by **bajaman** » 30 Oct 2007, 23:39

At least we know that Xotics opinion is that the correct place for CC-mojo is in series with the signal before the output

Yep -rolls off the extreme high end due to the lousy carbon granular construction - also adds noise too.

bajaman

axiss · Post by **axiss** » 31 Oct 2007, 01:17

bajaman wrote:
At least we know that Xotics opinion is that the correct place for CC-mojo is in series with the signal before the output
Yep -rolls off the extreme high end due to the lousy carbon granular construction - also adds noise too.
bajaman

So, the million dollar question is: what should we use small caps for?

The better answer I can find is: maybe they didn't care much about the high end roll off, maybe they were just after that pinch of extra noise.

About the best place for the CC mojo, it's probably as close to the input as possible, so you get the most gain over that small noise and turn an ordinary distortion box into a noise box, or as a true booteeker would say, "an effect on its own", "tone nirvana unheard before" or "(add your favorite Lovepedal or Zachie description here)".

Silent Fly · Post by **Silent Fly** » 08 Apr 2009, 11:46

Enjoy

culturejam · Post by **culturejam** » 08 Apr 2009, 14:20

Awesome.

Just added this to the White List

Silent Fly · Post by **Silent Fly** » 08 Apr 2009, 16:38

culturejam wrote:Awesome.

Just added this to the White List

It would be even more awesome if someone draw a schematics from my pics/values

soulsonic · Post by **soulsonic** » 08 Apr 2009, 19:19

Great job, man!
I'll get to work drawing up the schematic.

Silent Fly · Post by **Silent Fly** » 08 Apr 2009, 19:35

soulsonic wrote:Great job, man!

Thanks for your kind words

soulsonic wrote:I'll get to work drawing up the schematic.

...and I look forward to see the schematics

The Rotagilla · Post by **The Rotagilla** » 08 Apr 2009, 19:43

Silent Fly wrote:
soulsonic wrote:Great job, man!
Thanks for your kind words

soulsonic wrote:I'll get to work drawing up the schematic.
...and I look forward to see the schematics

Correct me if I'm wrong but don't we already have a schematic and layout?

Fuzzer · Post by **Fuzzer** » 08 Apr 2009, 20:13

There are two other threads addressing this pedal,

viewtopic.php?f=7&t=262
viewtopic.php?f=7&t=843

And in a recent thread, regarding low output from the AC, there was a schematic linked which had the changes to make it an RC.

http://schematic.exteen.com/xotic-rc-booster-ac-booster

soulsonic · Post by **soulsonic** » 08 Apr 2009, 20:26

Yes, but that schematic and project is inaccurate to the RC Booster. As you can clearly see in the photos, it doesn't even include the correct number of diodes, which surely has a huge impact on how it distorts.

Fuzzer wrote:There are two other threads addressing this pedal,

viewtopic.php?f=7&t=262
viewtopic.php?f=7&t=843

And in a recent thread, regarding low output from the AC, there was a schematic linked which had the changes to make it an RC.

http://schematic.exteen.com/xotic-rc-booster-ac-booster

Spazzmatazz · Post by **Spazzmatazz** » 08 Apr 2009, 20:47

it's two side pcb?

I was recomended to build one of this.
what's the difference between the AC and the RC?
I want a clean booster.

soulsonic · Post by **soulsonic** » 08 Apr 2009, 20:57

Spazzmatazz wrote:it's two side pcb?

I was recomended to build one of this.
what's the difference between the AC and the RC?
I want a clean booster.

Yes, two sided. The main difference between this and the AC is that the RC has less gain and additional diodes in the feedback loop which raise the level at which limiting occurs. It also does it's limiting symmetrically, in contrast to the AC which does it asymmetrically. The low frequency bandwidth is wider as well.
It looks like it is a clean boost - certainly cleaner than the AC.

briggs · Post by **briggs** » 08 Apr 2009, 23:39

Nice work Silent! Finally a true schematic

apart from the old sanded opamp!

Silent Fly · Post by **Silent Fly** » 09 Apr 2009, 00:15

Spazzmatazz wrote:[...]
what's the difference between the AC and the RC?
I want a clean booster.

You may want to check the Xotic web site. You can find specs and videos.

If you look for a clean booster the RC is closer to what you want. You can also add a switch to remove the clipping diodes for an extra-clean sound.

Fuzzer · Post by **Fuzzer** » 09 Apr 2009, 02:11

soulsonic wrote:Yes, but that schematic and project is inaccurate to the RC Booster. As you can clearly see in the photos, it doesn't even include the correct number of diodes, which surely has a huge impact on how it distorts.

Sure, I was just trying to reference every bit of data that is around the forum, so they can be merged and after that, emphasize on the correct info.

soulsonic · Post by **soulsonic** » 09 Apr 2009, 07:20

Here is the schematic:

Xotic - RC Booster [traced]