»Need FET Bypass Scheme«

[difedetry]

Hello guys

I'm wondering if someone could help me and share a bypass FET
scheme. I know that should be very easy to split a switching
scheme from a original schematic (like Boss or DOD, which I
have a lot) but I'm not sure if I'll do it well. I wanna make
a PCB layout for it and put it into my site to share with all
of you. I tried electronic swtiching with CD4053 without good
results. In some cases it add noise or oscillation with a
distortion.


thanks in advance  


» Diego

[Peter Snowberg]

Hi Diego,

I know there was a recent post here (maybe from 1 month ago) that shows JUST the switching logic of a Boss pedal, but I could not find it when I searched.

I hope somebody will see this and re-post.

I did find a couple of posts worth viewing on the subject:
http://hammer.ampage.org/files/dodswitch.gif
http://members.shaw.ca/roma/switching.html

http://members.shaw.ca/roma/ great stuff here!

Good luck,
-Peter

[Marcos - Munky]

You will find a modded Boss switch in my site, take a look.

[Peter Snowberg]

That's what I was remembering. Thanks Marcos!

http://www.geocities.com/munkydiy/

eswitch.gif is what you want.

[Jim Jones]

Hi Diego,

Out of curiosity, how did you use the 4053?  Did you try Laurier's cicuit?

Thanks!

Jim

[Marcos - Munky]

Hey Jim, I built a bypass using the 4053. I used the last schematic in Laurier site, the one with another CMOS. Works in the first try, but I found two problems. Sometimes it didn't bypass, and you need to press the switch a few times (I think this could be a problem in the switch, or all electronic switch have this problem, because I played in a Ibanez SP-5 with the same problem). The other problem is if I connect the LED and press the switch, the LED do the normal work, but the effect isn't bypassed. If I disconnect the LED, all works.

[Jim Jones]

Hi Munky,

Thanks for the info!  I think I'll try it out.

Jim

[difedetry]

Peter:
I already knew those both links: from Laurier Gendron
(http://members.shaw.ca/roma) I've made his switch with CD4053-CD4011 and it sound awful: drop volume in bypass and add distortion when engaged... then I gave a try to R.G's switch with CD4053-CD4049 and almost the same. Maybe I've made a bad PCB design ?, check it
out if you want:

http://www.difedetry-fx.com.ar/iframes/switch1.htm

As for the DOD switch from Mark Hammer's site maybe I should try it but
I was thinking about something without ICs; it has a CD4007 and I'm in
doubt to make it.

Thanks Peter!


Marcos:
That's what I looking for...
Q: what's the purpose of the added parts?
I don't see them on the schemes that I have of other Boss circuits.

Thanks Marcos!

Jim:
I did use CD4053 with 4011 & with 4049...
I tried Laurier's circuit and it sound bad to me


OK, I'm ready to go nuts with the PCB designing ...
I have work to do! cya

sorry my english


» Diego

[Marcos - Munky]

I don't know why there are some parts added. The only thing that I know is that is a modded version.

[difedetry]

ok. thanks Marcos... i'm beginning the PCB design.
I let you know when I have something...

» Diego

[rx5]

forget chip bypass... I use JFETs..low noise.....or no noise at all...just follow marcos site....

he posted my modds there....    :wink:

tested it 3 time allready.... just for a brute punish, I even used it on obsidians with ulta high gain dist.... aND it would not "leak"..... :wink:


Those are MY perfect solution for bypass....because I dont have access to carlings.... hehe :twisted:  :evil:  :twisted:

[The Tone God]

forget chip bypass... I use JFETs..low noise.....or no noise at all

I never liked FET style bypassing but I love "chip" bypassing. I've been using the 4066 for more then five years in several different types of effects. I don't think one should just discount "chip bypass". I haven't used 4053s so I can't comment on them.

Check out the "Wicked Switches" article about how I do my electronic bypassing.

Andrew

[rx5]

the tone god,


dont you hear "thump" when siwtching states??


tried the 4053 and 4066....I hear "thump" thats why I resorted to Jfets...




-ralph

[The Tone God]

dont you hear "thump" when siwtching states??

tried the 4053 and 4066....I hear "thump" thats why I resorted to Jfets..

A "thump" ? I don't think I've heard that or atleast its not very common for me. I got more "pops" then anything although would could just be having a difference in opinion with the use of our terms. There are few simple things that can be done to minimize these problems which I do on my effect boards.

Andrew

[difedetry]

Ok, first of all I've made this layout because it looked less
complicated than the Boss one. It's based on DOD bypass switchs
from Mark Hammer's site, Albeit it was made it a little quick
I think it's right, take a look :

http://www.difedetry-fx.com.ar/iframes/switch2.htm

you'll only have access to the layout from this links because
I have not test it yet and there isn't any PCB download too.

If someone could make a brief explanation about how it should
be wired to achieve a normal function of bypassing would be
nice cuz I have some doubts... If I'm understanding well I
have to tie B-C points as the input, being A and D the output
and fx-output respectively...
Give me a hand with debugging cuz I only checked a couple of
times the PCB ...

Now I'm starting the Boss style switch PCB design...

Ralph: I dont have access to carlings either !  :twisted:
thanks for your mods...

regards :wink:


» Diego

[rx5]

Diego,

Im gonna wait for your BOSS layout .. :wink:       I know it would be another clean layout....  cool man... nice work.... :twisted:

I think the DOD style bypass should also work..from the looks of it... havent tested it though.... also, I dont have access to CD4007, thats why I resorted to transistor logic... but still its the same functionality....


Andrew,

I think "pop" was the right word for it.....

Anyways, havent gone far on the chip "bypass"..... my first try w/ CD4053 was a "pop".... next , 4066 was also "pop".... thats why I just used Jfet.... :twisted:  

[plucky]

Can anybody send me the pcb for the boss electronic switching?... I saw the schematic but I´m really bad doing pcb's... please  :oops:

thanks

patrick
plucky_00_@hotmail.com

[petemoore]

Id say, ..that'd one fairly large board.
 I thought of doing one of those for the challenge and Jfet Experience..
 Too big, too expensive, too hard looking.
 I suppose they have a better longevity track record than switches, changing a switch isn't that much trouble IMO, ..lets see how many BP switches = $ for Jfet switcheing...
 Instead I built a buffer to try the buffer effect.
 The main reason I would take on such a challenge is for remote switching.

[plucky]

Does anybody know what is the power consumption of a cd4049 flip flop with led???

[gez]

Does anybody know what is the power consumption of a cd4049 flip flop with led???

Not much more than the current flowing thru the LED.  There'll be a tiny bit of current that flows during switching and a little when the cap charges up, but we're talking insignificant amounts and only for short periods of time.