BAJA Sagittarian Charger (mini KLON)

dcountry13 · Post by **dcountry13** » 27 Sep 2011, 16:38

pinkjimiphoton wrote:as per the layout picture of barry's site, the small diode at the upper left part of the board, the 1n470 or whatever is INDEED PICTURED BACKWARDS. i spent two weeks fucking around trying to debug the thing, and as soon as i turned the diode the other way, success. if in doubt, socket mount it. hope this spares ya some agravation. the two things that get overlooked the most on layouts are diode orientation, and pot pinout. the only prob on this board's layout is that one diode.

Thanks for looking at that. I did the wiring diagram for Barry's site and did flip the 1N4001s that are backwards on the PCB overlay on the 1st page of this thread. I must not have noticed the 1N4742 being backwards on the original PCB overlay, too.

Funny thing is.....I have built these before and automatically put the Zener in the right way by habit.

I will have Barry update the photo on his site ASAP..

jhlind · Post by **jhlind** » 08 Oct 2011, 21:18

dcountry13 wrote:I will have Barry update the photo on his site ASAP..

Did Barry update the photo on the site?

If so, how do we get to it, since only moderators are now allowed in the unsupported build area?

tx,
jhlind

roseblood11 · Post by **roseblood11** » 17 Dec 2011, 19:49

I got an old pcb that is labeled as "Baja Sagittarian Charger 240508".
I spot some changes but it should be possible to build the new version on this board.

Can someone please post the schematic and the overlay picture for that 240508 version?
(or send to me by mail: [my username][at]gmx.net )
Would be really helpful to find the differences...

mojah63 · Post by **mojah63** » 17 Jan 2012, 14:57

Finally boxed this one up. It's been sitting populated on my bench at work for a few years.
Had a problem at first start up, the 2nd tl072 had one pin not in the socket. Sounds
pretty cool through an amp modeler and headphones. Hopefully I'll get to try it out with the big rig
at rehearsal this week. My board was the 240508 and used the 241108 layout. Like everyone has
commented the + marks are where the cathodes (-) should be. Big thanks to all for this one esp Baja

..
Now to finish off the rest of my new year's list.

pinkjimiphoton · Post by **pinkjimiphoton** » 17 Jan 2012, 15:27

i think the 40472 diode is the only one where polarity really matters...that was the only one that jammed me up, the 1n40001's i assumed were just diode clippers..guess i lucked out and got 'em in right...

glad you're up and running!!!

i'm building my second charger, the first one paid off a pawn and got me my echoplex back.

pinkjimiphoton · Post by **pinkjimiphoton** » 21 Jan 2012, 22:46

found a way to kill..and a possible cause of..charge pump whine.

the cause (on mine)a small bridge between the jumper at ic 2 pin 1that goes to the + side of c13 and r 21

that's the jumper above pin 1 of the horizontal chip, and the 1k resistor that connects to pin 1 (with terms to the left from the back of the pot with pin 3 on top)of the volume pot. if you have a bridge there, the circuit will whine and if it passes signal be well below unity gain.

the other thing i found was to jumper pin 7 of the charge pump to ground. no more whine. sounds great.

as for 1n4742....band to B+, anode to ground

1n4001's...
top, band to left
bottom, band to right.

hope this helps.

may also be able to short 6 and 7 of cp together...they're not connected on the schem, but seem better earthed (pin 7 anyways)

cp i used is maxim icl7660...lt1054 got hot enough to burn the fuck outta me...may try it anyways.

hope this helps someone.

pedal sounds GREAT. i've built the buffered and unbuffered, buffered sounds somewhat better.

peace

jlag · Post by **jlag** » 23 Jan 2012, 05:11

hey guys, really excited to tackle this build. just putting it out there now, i am new to building a board from scratch. ive modded a few pedals but thats where my experience stops. i know a few will tell me not to be my first build but im confident i can do it. my worry is just in ordering parts. i've built a cart on mouser.com
http://www.mouser.com:80/ProjectManager ... 24a3df1b66 is a link to my saved cart. it includes resistors, caps, and diodes.
my worry is all the assembled boards im seeing have box capacitors and im pretty sure i don't have any in the cart. a lot of the voltages are way higher than required as well. all the carbon film resistors are xicon and the metal film resistors are vishay/dale.

im sorry if this bothers anyone, again im new to the purchasing parts thing aside from going to radioshack and picking up a few pieces. i've read through all 22 pages of this thread and have learned a ton from everyone.

also, im planning on socketing the 1N4001's and a pair of BAT41's and wiring in a switch between them. i've seen someone do it but didnt have any info on how he did it. im sure i can figure it out with a piece of veroboard or something but if anyone knows the best way to do it, i would be much obliged.

any help or advice you can give me would be really appreciated. again, im new to this and learning as much as i can from all of you. thank you for all the info so far.

-jlag

pinkjimiphoton · Post by **pinkjimiphoton** » 23 Jan 2012, 16:17

if you're new at this, be extra super special careful...there's many many places where a solder bridge WILL FUCK YOU UP. this isn't an easy build for even an intermediate builder...i've got over 20 pedals built, including two other versions of this, and i STILL had to debug the fuck out of it...and made an almost imperceptible bridge. it's tougher than you think.

take your time, check each connection against the schem and layout, and check continuity everywhere. some little traces there, close to each other.

and if ya wanna kick in the ass, don't install the 47k resistor...replace it with two wires going to a footswitch...put the 47k on one side, and a 4.7k on the other for a huge gain boost...try it and see if you like it.

jlag · Post by **jlag** » 23 Jan 2012, 19:15

Thanks for the tip! Yeah I actually blew the layout up an spread the traces out a bit in photoshop. I plan on using a decent size enclosure so it'll be ok a little bigger. But yeah I'll definitely try the resistor replacement. Do you think I'm ok without the box capacitors though? That's really all I'm concerned about right now. Are they just to save space on a small board? I know the mojo pedals build used all tantalum caps I believe.

Seiche · Post by **Seiche** » 23 Jan 2012, 19:21

jlag wrote:Thanks for the tip! Yeah I actually blew the layout up an spread the traces out a bit in photoshop. I plan on using a decent size enclosure so it'll be ok a little bigger. But yeah I'll definitely try the resistor replacement. Do you think I'm ok without the box capacitors though? That's really all I'm concerned about right now. Are they just to save space on a small board? I know the mojo pedals build used all tantalum caps I believe.

be careful with caps:
tantalum caps = polar
electrolytic caps = polar (those are interchangeable when you've got the same values)

nonpolar caps: boxcaps, greencaps, panasonic (the red ones), ceramics, silver mica, styroflex and many more, those are interchangeable with the same values.

so you are right, the mojopedals klone uses all tantalum on the polar caps. The nonpolar ones are mostly box caps.

rocklander · Post by **rocklander** » 23 Jan 2012, 20:06

if you blew the image up, then check the spacing on the ICs..

jlag · Post by **jlag** » 23 Jan 2012, 23:27

Alright so I don't necessarily need the boxcaps as long as the values match. And yeah I kept the spacing on the ic chips the same.

jlag · Post by **jlag** » 25 Jan 2012, 21:04

Also, recently just got a hold of some LM313h diodes. So instead of my original plan to switch between the BAT41s and the IN34As, I'll be switching between them plus the LM313Hs. Anyone know of a good switch to do this? I think I wanna go the mini toggle route.

jhlind · Post by **jhlind** » 30 Jan 2012, 06:34

Need help.

Second build. First one worked great.
This one has no output. Traced signal. It stops coming out of the second TL072 (U2a) at pin 1. Looked for solder bridges. Don't see any.

Anyone had the problem before?

LOVED the first one I built. Sold it. Looking forward to getting this one working.

Thanks for your help in advance.

j

roseblood11 · Post by **roseblood11** » 30 Jan 2012, 09:06

jlag wrote:Also, recently just got a hold of some LM313h diodes. So instead of my original plan to switch between the BAT41s and the IN34As, I'll be switching between them plus the LM313Hs. Anyone know of a good switch to do this? I think I wanna go the mini toggle route.

Get a 2pdt on/on/on switch. Then find out, which lugs are connected when the toggle is in middle position.

: clipping dioden switch2.jpg (16.43 KiB) Viewed 3303 times

jhlind · Post by **jhlind** » 30 Jan 2012, 15:24

Trying to debug my build. Maybe this will help:
Voltage readings from ICs are:

Supply - 9.65V

IC1 (top left TL072 on pcb)
1. 4.44
2. 4.44
3. 1.21
4. 0
5. 4.05
6. 4.16
7. 2.99
8. 9.65

IC2 (far right TL072)
1. -7.62
2. -7.27
3. 4.38
4. -9.60
5. 4.38
6. 3.66
7. -7.59
8. -8.17

IC3 (7660 charger)
1. 9.62
2. 5.75
3. 0
4. -3.87
5. -9.61
6. 4.78
7. 4.44
8. 9.63

Any help in deciphering what these voltage readings are saying is greatly appreciated.
Already built one on same pcb, and it worked great first time. No debug.
Not sure what I've done on this one.

Thanks in advance,

j

aegert · Post by **aegert** » 01 Feb 2012, 12:00

Hey finished my build. Had a bad charge pump but slapped a new intercil scpa in and it lit correctly without choking out.

1) First impressions are that the buffer is way way way below unity gain so I will need to change the ratio of the resisters to attain unity . It is extremely colored not to my tastes. I have to check the components around it to make sure I didn't make a factor of 10 value mistake but I was pretty careful on assembly by doing meter readings over every one when putting in circuit.. more likely I will just go with a try bypass of it as I have buffers all over my pedal bard and on the amp switcher.

2) gain vs volume controls are a precarious balance. small movements in gain create very large movements on output volume. I have a 250kB dual for my gain pot. I cant see that a 100k will make much of a difference it should give me more range. Might change the tone sound though. will see...

3) Tone is very very trebley I have a BBOPA in the tone IC. Any ideas for best opamps for this before I rip the tone stack apart and re voice the thing? Has anyone fooled around with the tone stack or have any mod ideas?

I will post pics in a few any input is appreciated. I'm getting lazy in my old age LOL

pinkjimiphoton · Post by **pinkjimiphoton** » 01 Feb 2012, 13:10

won't going with a 250k give you LESS gain? that could lead to it sounding more like a treble booster, louder, but less distortion.
just thinking off the top of my head here..

aegert · Post by **aegert** » 01 Feb 2012, 20:29

any ideas on why the buffer would be less than unity gain? Is it supposed to be less?

Seiche · Post by **Seiche** » 01 Feb 2012, 20:42

aegert wrote:any ideas on why the buffer would be less than unity gain? Is it supposed to be less?

have you checked the colour codes of the resistors (especially around the buffer)?

BAJA Sagittarian Charger (mini KLON) [documentation]