Xotic - BB Preamp  [traced]

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

Re: Xotic - BB Preamp

Postby BennyBoop » 18 Jun 2009, 14:42

How will it sound with a Burr Brown OPA2134PA? Anyoune tried it?
What other IC's have you tested?
User avatar
BennyBoop
 
Posts: 43
Joined: 02 Jun 2008, 22:01
Location: Linköping, Sweden
Has thanked: 0 time
Have thanks: 0 time

Re: Xotic - BB Preamp

Postby mrkaploca » 26 Jun 2009, 16:52

what are original transistors and IC???
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby chicago_mike » 26 Jun 2009, 17:24

lm353 or lf353 or something like that. Not your everyday tl072

I'll be building these for bass and will use opa 2134's I think. I really like those.

The npn/pnp's though Im not sure whats used there.
Skyline FX 2013
User avatar
chicago_mike
Opamp Operator
 
Posts: 1711
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Have thanks: 275 times

Re: BB Preamp, new layout!

Postby mrkaploca » 06 Jul 2009, 03:19

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

what about the output transistor here?+4,5V is not connected to base but to emmiter???
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby Silent Fly » 06 Jul 2009, 08:23

I am not convinced by the Q2 connections either... :hmmm:
"Remember - all I am offering is the truth, nothing more". Morpheus
User avatar
Silent Fly
Resistor Ronker
 
Posts: 423
Joined: 27 Feb 2008, 23:40
Has thanked: 20 times
Have thanks: 37 times

Re: BB Preamp, new layout!

Postby mrkaploca » 10 Jul 2009, 00:28

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

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

I tried this version,not working.I fixed output transistor pinouts(original are not correct,Va should go to base not emmiter,and emmiter to ground.)but still doesnt work.does anybody have working layout??
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby Silent Fly » 10 Jul 2009, 09:44

The bias of Q2 doesn't look right. As a test, I suggest you try pick up the signal from terminal 2 of the LEVEL potentiometer. If you hear a sound it's Q2. The connections of IC2A also look wrong.

I would recommend you have a look to this version.
"Remember - all I am offering is the truth, nothing more". Morpheus
User avatar
Silent Fly
Resistor Ronker
 
Posts: 423
Joined: 27 Feb 2008, 23:40
Has thanked: 20 times
Have thanks: 37 times

Re: Xotic - BB Preamp

Postby mrkaploca » 10 Jul 2009, 16:35

Silent Fly wrote:The bias of Q2 doesn't look right. As a test, I suggest you try pick up the signal from terminal 2 of the LEVEL potentiometer. If you hear a sound it's Q2. The connections of IC2A also look wrong.

I would recommend you have a look to this version.

yes but I am realy bad in layout designing so I ask if somebody has working layout.I have a gig in france for 6 days and I realy need to finihs it till then!!!!!!!!HELP
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby zxbreak » 15 Jul 2009, 14:28

Hi!
Help me with a small questions.
BB PLUS preamp has a B>A and A>B channel selector. But how? :shock: Relays? DPDTs? or?
In the Zvex Box of Rock have been realized as A(on\off)>B(on\off) chanel only.
zxbreak
 
Posts: 1
Joined: 13 Jul 2009, 09:25
Has thanked: 0 time
Have thanks: 0 time

Re: Xotic - BB Preamp

Postby mrkaploca » 24 Jul 2009, 15:51

Da Cat wrote:Thanks kusi, you the man :D
and the corected version:
Image
Image

OK,I ve built this version,engaged it and all I got is a HUM.Every pot is responding,difference can be heard when I turn gain pot,bass,treble,and the volume increases,but ll that is comming out is a hum sound no metter what you play(no distortion,no nothing).What could be the problem??
Thnx!!
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby madbean » 24 Jul 2009, 17:21

Re-flow your solder. You might have a solder bridge somewhere.
madbean
 

Re: Xotic - BB Preamp

Postby mrkaploca » 27 Jul 2009, 16:26

madbean wrote:Re-flow your solder. You might have a solder bridge somewhere.

No,that's not the case,I rechecked all the paths.What else causes only hum sound.Transistors must be ok soldered or else there wouldn't be any sound at all??IC's????Someone help!!
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby modman » 28 Jul 2009, 02:35

mrkaploca wrote:
madbean wrote:Re-flow your solder. You might have a solder bridge somewhere.

No,that's not the case,I rechecked all the paths.What else causes only hum sound.Transistors must be ok soldered or else there wouldn't be any sound at all??IC's????Someone help!!


You used a layout that somebody said was/you hope is verified. In that case and in fact always, you should check your build against a correct schematic or use the Audio Probe to trace your guitar signal.
"The whole point of diy is diy. It's not dsoiyathodtr - do some of it yourself and then have others do the rest" (paulc)
User avatar
modman
a d m i n
 
Posts: 4246
Joined: 19 Jun 2007, 17:57
Has thanked: 2886 times
Have thanks: 495 times

Re: Xotic - BB Preamp

Postby TheLemon » 28 Jul 2009, 07:32

mrkaploca wrote:
Da Cat wrote:Thanks kusi, you the man :D
and the corected version:
Image
Image

OK,I ve built this version,engaged it and all I got is a HUM.Every pot is responding,difference can be heard when I turn gain pot,bass,treble,and the volume increases,but ll that is comming out is a hum sound no metter what you play(no distortion,no nothing).What could be the problem??
Thnx!!


You might have a grounding issue, maybe a connection missed
TheLemon
Breadboard Brother
 
Posts: 100
Joined: 15 Oct 2008, 04:55
Has thanked: 9 times
Have thanks: 21 times

Re: Xotic - BB Preamp

Postby Da Cat » 28 Jul 2009, 12:21

Hmm, my bb is working fine with this layout i made....
Hum sounds like a ground problem. Check the power filtering diode going to ground - orientation!
Check the schematics kusi posted - i made layout after that one.
And also check the transistors - try 2n5088 or 2n3904.
Da Cat
 
Posts: 31
Joined: 25 Oct 2008, 06:25
Has thanked: 0 time
Have thanks: 1 time

Re: Xotic - BB Preamp

Postby mrkaploca » 29 Jul 2009, 16:04

Da Cat wrote:Hmm, my bb is working fine with this layout i made....
Hum sounds like a ground problem. Check the power filtering diode going to ground - orientation!
Check the schematics kusi posted - i made layout after that one.
And also check the transistors - try 2n5088 or 2n3904.

I changed 2sc1815 transistors to 2n5088 and I finally made it work.Everything works fine except when I increase the gain potentiometer-then there is alot of background noise(hum)present :hmmm: .It can not be heard when I play but when I stop a noise appears.On a very low gain values it's ok.I put 1M log pot instead of linear one and I put 20k resistor(on the second gain stage of the first IC)instead of 19k.Can that cause the problem?
Sorry guys I torture u but I wanna make it right ,I really like the sound of bb preamp!!!
thnx!!!!
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby mrkaploca » 31 Jul 2009, 10:20

anybody with good advice??
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby mrkaploca » 04 Aug 2009, 17:13

mrkaploca wrote:
Da Cat wrote:Hmm, my bb is working fine with this layout i made....
Hum sounds like a ground problem. Check the power filtering diode going to ground - orientation!
Check the schematics kusi posted - i made layout after that one.
And also check the transistors - try 2n5088 or 2n3904.

I changed 2sc1815 transistors to 2n5088 and I finally made it work.Everything works fine except when I increase the gain potentiometer-then there is alot of background noise(hum)present :hmmm: .It can not be heard when I play but when I stop a noise appears.On a very low gain values it's ok.I put 1M log pot instead of linear one and I put 20k resistor(on the second gain stage of the first IC)instead of 19k.Can that cause the problem?
Sorry guys I torture u but I wanna make it right ,I really like the sound of bb preamp!!!
thnx!!!!

So guys what could be the fault??increasing the gain pot a background noise (hum)appears!!!! :slap: :slap: :slap:
mrkaploca
Breadboard Brother
 
Posts: 142
Joined: 23 Nov 2008, 16:45
Has thanked: 15 times
Have thanks: 12 times

Re: Xotic - BB Preamp

Postby ODwan » 05 Aug 2009, 16:39

Hi!
Could be bad filtering of the power supply --> try with battery.
Could be hum pickup from external source like mains wire, transformers, lighting..... either through guitar pu's or circuitry.
Is the circuit shielded/in a box?
Hope this helps some!
Timo
ODwan
 
Posts: 39
Joined: 03 Jan 2008, 20:16
Has thanked: 0 time
Have thanks: 0 time

Re: Xotic - BB Preamp

Postby diggum12 » 28 Aug 2009, 18:59

Has anyone tried this without the buffers? I may try it this weekend if I get time.
"Now we cheer if someone get's a tweed champ working. I feel like the future was here and we traded it away for trinkets." -diagrammatiks

ayayay! on the other site
User avatar
diggum12
Solder Soldier
 
Posts: 196
Joined: 19 Jun 2009, 18:13
Has thanked: 3 times
Have thanks: 12 times

PreviousNext

Return to Boutique Stompboxes dissected...

Who is online

Users browsing this forum: bobbass4k, hlaph, Leeuujay, lukatosh and 17 guests