Got a request for the BB Preamp, but not the current version. The earlier version uses a dual-gang pot for the Level control and apparently more bass response. Like many of Xotic's offerings the BB owes a lot to the classic Tube Screamer. Schematic can be found
here.
If you'd prefer to build the newer version without the dual-gang Level pot, you can use the same board. Just remove the 1µ capacitor and the 1k and 47k resistors in the bottom right side of the board and replace with a jumper like this:
In the newer version, where does level 1/2 go?
ReplyDeleteI mean connected..
DeleteYou won't use the Level A connections. In the original version the Level pot was dual gang. The newer version just uses a regular single gang pot, which are the same as the Level B connections in the layout (top of the board).
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DeleteOk pal I get it.
DeleteI got a BB preamp made by a friend using different schematic, but it is now broken. I'll rebuild it later using its components base on your layout after finishing my demo tape fuzz. Thanks man
Awe
oh David, you always beat me
ReplyDeletejust made layout for friend, Andy Timmons die hard fans in perf with onboard pots wannabe
but worse, cause have 6 jumper! :( hehe
@berkicau = maybe this scheme help you build two version
https://1.bp.blogspot.com/-JNsyPpyyt7U/VtRuHepg5II/AAAAAAAAAOA/Ux3Fre0_7uo/s1600/bbprea.png
put inside big box to small box. or thrash the big box! hehe
On board pots are always a good thing though. 6 jumpers with on board pots is ok in my book. If you don't mind sharing, send it over and maybe I can make a PCB version too and post our combined work if you're cool with that.
Deletecheck your fsb inbox :D
DeleteI have a BB +. I recently played the BB comp and LOVED the setting with no compression. Can anyone tell me how to mod my Plus to have no compression instead of "hard/soft". Ideal world the switch would be "off/soft." Any tips?
DeleteUal
ReplyDeletewow!!!
ReplyDeleteif possible, can you make the layout of BB +. maybe it would be a good idea to separate the sides. I am very interested in the B side, which is like a drive and has much more gain.
here the link: http://freestompboxes.org/viewtopic.php?f=7&t=19528&p=248830&hilit=bb+preamp#p248830
Brejna made a layout but I have not the schematic to be corrected if it does not work.
the schematic according Brejna, is from Darmstat
*** Sorry if this is not the place to do this, but I did not find your email as previously
Francisco, the schematic is gone in fsb thread. Can you upload?
Deletehonestly, i have bb+ and early bb, but in sprint and double side. so, i never built that
please a look http://www.mediafire.com/download/gldlcoxeupw1bfy
my eyes is trouble see the B side in there
sorry forgot where i get that
that's the schematic!!!
DeleteIt was the same earlier drawing. It was the same that was in the tread that I put up.
i asked for it, you made it !! YOU ARE SO GREAT DUDE !!
ReplyDeleteRafik
you can check this, VERIFIED !!!
ReplyDeletebut i found some little problems: https://goo.gl/photos/H5kfuspXjYZZ8CEt7
And the Gain pot is more useful with a Log pot --> A1M
sounds great thanks !!
Great site by the way !
cheers from Chile !
That for catching those and thanks for verifying!
DeleteI have a BB +. I recently played the BB comp and LOVED the setting with no compression. Can anyone tell me how to mod my Plus to have no compression instead of "hard/soft". Ideal world the switch would be "off/soft." Any tips?
ReplyDeleteHi Jp, if you want no compression, just remove the 4148 diodes, or add a switch for more versatility (see the link here: http://tagboardeffects.blogspot.fr/2012/10/xotic-bb-preamp.html).
DeleteCan I replace the 2SC1815 transistor to BC517?
ReplyDeleteYou could try it, but it's probably overkill as the BC517 is a darlington. A BC550 would be better suited. Just mind the pinout.
DeleteI use 2N5088, working fine to me.
DeleteWhat does the yellow trace stand for?
ReplyDeleteVoltage reference (4.5v)
DeleteCan 1N5818 replace with 1N5819?
ReplyDeleteThat should be fine.
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ReplyDeleteThose are transistors. BCE indicates the pinout.
Deletelol.
Deleteso which trnsistor did you use?
and can it turn for bassist?
Deletecan it turn for bassist?
ReplyDelete2sc1815 is ECB
ReplyDelete2n3904 is EBC
You need to swap the Base & Collector if you use the 2N3904
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ReplyDeleteWorking for me in new version... Perfect!
ReplyDeleteNo encuentro en el esquema electronico del pedal los resistores de 19K y 1K que salen conectados juntos de la patilla dos del TL072. Es una reforma del circuito y que en el esquema original no figura?
ReplyDeleteNo entiendo porque la pcb usa un opa del JRC4558 y otro del TL072 en la primera parte del circuito, ya que en el esquema electronico del pedal no es asi. O en realidad no existe un TL072 en el pcb y son dos JRC4558?
ReplyDeletehow to make a modification under the bass guitar ??
ReplyDeleteFor level use dual gang, but this layout just have 3 pin,
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ReplyDeleteHow to increase gain for this pedal?
ReplyDeletePedal saya berbunyi timbul tenggelam di sertai bunyi seperti potensio kotor yg di putar putar,adakah yang dapat membantu untuk masalah saya??
ReplyDeleteMy pedal appears and sinks accompanied by a sound like a dirty potenti being rotated, can anyone help with my problem??
ReplyDeletehola señores ...alguien puede subir o revisar el enlace del esquema por favor. Gracias.
ReplyDelete