Xotic - BB Preamp  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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666
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Post by 666 »

kusi wrote:the L.A. Boutique-Screamer is a little bit modified...

here you find the original BB:
http://forum.musikding.de/cpg/displayim ... 4&pos=-424

(+ and - inputs of the gainstage are in wrong direction... ;)


regards, ksui
Hello Kusi... in this schematic, is this 100k pot "Level A" along with the 47k resistor are OK or should I stick in the first schematic? And what about the 1uF-1k RC behind the "Level A" pot?

Thanks.

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Krinkle
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Post by Krinkle »

kusi wrote:the L.A. Boutique-Screamer is a little bit modified...

here you find the original BB:
http://forum.musikding.de/cpg/displayim ... 4&pos=-424

(+ and - inputs of the gainstage are in wrong direction... ;)


regards, ksui
Why are there 2 level pots? I thought this was the original BB? Am I missing something?

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kusi
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Post by kusi »

hello,

this is a dual-pot!

regards, kusi

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twostring
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Post by twostring »

Any possibilities for a vero layout, or would vero be too difficult to manage? I'm trying to work on a very layout based on a TS vero layout I found, but there is much I don't understand. For the first op-amp stage, should the signal enter at the 5th or 6th pin? The vero layout I have for the tube screamer shows the signal entering at pin 3, but the schematic I have for the tube screamer shows the signal entering at pin 5. I understand you can use either op-amp, but what would make better sense when building up a circuit like the BB Preamp?

I'm trying here, but I have to admit there is a lot I don't understand here. I would like to see a layout by one of the gents here that has a bit more experience.

Thanks,

Chad

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twostring
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Post by twostring »

Well, I gave it a shot. Maybe one of you more experienced designers might improve on it. Either way, I'd like some feedback. This is the first layout I've completed (or really attempted for the most part). I started with a Screamer layout and used it as far as I could, and I continued with the vero layout for the active tone stack that was posted in a build report for the BB Preamp. The layout kind of falls apart after the second op-amp stage. I would appreciate any pointers or corrections, and I'd like to make the board shorter as well.

Hopefully I didn't miss anything, but here goes...

Image

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ShortScaleMike
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Post by ShortScaleMike »

IC2 is missing a connection to pin4 for a kick-off

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twostring
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Post by twostring »

Just a quick question...anyone think about doing this one with a quad op-amp? It might make things a bit easier to arrange. Any negatives to this?

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Da Cat
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Post by Da Cat »

Hi!

This is a great forum!
Here is my little contribution...

I have modified layout from this thread:
https://www.freestompboxes.org/viewtopic.php?t=1770
I used this schematic:
http://forum.musikding.de/cpg/albums/us ... preamp.pdf

And here are the layout and PCB.
Image
Image

and also the diy file is added as the attachment.

I made it whit beta version of DIY layout creator (Java)

Feel free to comment. I haven't built it yet...
Can anyone tell me if it is corect?

thanx
da Cat
Attachments
xotic_bb.diy
(149.78 KiB) Downloaded 582 times

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kusi
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Post by kusi »

hi,

i just checked the IC-Pinouts. IC1a is wrong in your layout, because i draw an error in the schematic as i wrote it before in this thread. please google for "non inverting op-amp stage", and you will see the basic function of IC1a.

regards, kusi

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Da Cat
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Post by Da Cat »

Thanks kusi, you the man :D
and the corected version:
Image
Image
Attachments
xotic bb_layout.diy
(149.62 KiB) Downloaded 682 times

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Da Cat
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Post by Da Cat »

...and now this wersion is also verified!
works like charm!

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quaternotetriplet
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Post by quaternotetriplet »

Hi, what ic are on the original

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audioguy
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Post by audioguy »

I get an error trying to open the DIY file... anyone else?

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miklax
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Post by miklax »

audioguy wrote:I get an error trying to open the DIY file... anyone else?
Cant open the file. either... :s

Can anyone post the offboard component connection to the board?

thanks

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Da Cat
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Post by Da Cat »

I made this pcb with diy layout creator beta (Java vesrion)
http://www.storm-software.co.yu/diylc/diylc_beta.zip

It is quite big, I will corect it when I have time.

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quaternotetriplet
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Post by quaternotetriplet »

da cat, sorry to thread jack my diylc java version thus not have a library. what is the problem?? BTW, im using vista

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darkglass
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Post by darkglass »

Hello, Im posting one layoout I designed with eagle for the BB Preamp, I used the schem traced by KHE founded in this forum...

So here it is!

Schem

Image

Layout

Image

And PCB

http://darkfinn.googlepages.com/BBPreampPCB.pdf

This layout is not verified though, I finished it yesterday, but Im quite sure it should work.

Best Regards

Douglas.

Enjoy
Attachments
BBPreampPCB.pdf
(118.35 KiB) Downloaded 185 times

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madbean
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Post by madbean »

Nice work. There seems to be more than one version of this schem, though. It looks like the one you've got here came from a trace done by KHE in Jan 2006. But there is another trace from later that same year that has uses a dual 100k for volume control.

Attached below is a pdf I have of the second trace. I have a layout of this one, but it's double sided.

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mrkaploca
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Post by mrkaploca »

Hello!
Can someone please tell what IC's and tranzistors are used for this pedal??

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mrkaploca
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Post by mrkaploca »

darkglass wrote:Hello, Im posting one layoout I designed with eagle for the BB Preamp, I used the schem traced by KHE founded in this forum...

So here it is!

Schem
http://darkfinn.googlepages.com/BBSchem.jpg

Layout
http://darkfinn.googlepages.com/Layout.jpg

And PCB
http://darkfinn.googlepages.com/BBPreampPCB.pdf

This layout is not verified though, I finished it yesterday, but Im quite sure it should work.

Best Regards
Douglas.
Enjoy
sorry,what is 9V1 pin near the 9Vpower pin???Im a bit bad in electr. :oops:
and what are original IC's and tranzistors?Is this layout verified?
THNX

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