want to build shaka tube but dont understand somethings

[mrfirstime]

Hi

I have always been interested in electronics and have finally decided to build a guitar pedal.  I have some tubes from another amp (home build but not by me) so I finally decided that the shaka tube looked like a great start.  I checked out the schematics and then the layout which looked great and promosing at first but then it all fell apart.  There are some things I dont understand which is due to total ignorance on my part and Im wondering if any one could help. Here are some questions I have.

1.  On the layout there is a red lead coming off the no4 pin of the tube which is 12vac.  Im not where this comes from.  Is it straight from the transformer?

2.  I have no idea where the toggle switch is on the layout or where it fits in.  I have looked on the FAQ but im unsure which is the in and out of the effects?

Is there a step by step walk through of this build anywhere.  I have checked everywhere but cant seem to find anything.

Thanks

[GibsonGM]

Hi Firsttime,
It's easier if you post a link to the schematic you're planning on using! I'm sure it's right here somewhere, but there are 10 places it might be (the Shaka has several 'incarnations').  Gotta be on the same page, then we'll be able to help you get started.
Happy building!

~Mike 

[mrfirstime]

Hi Mike

Thanks so much for your reply.  The first drawings I got were pdf's that I got from this site and they were of the layout in a non schematic format.(Looks neat and understandable except for those issues I had .http://www.diyguitarist.com/DIYStompboxes/ST1590BB.htm. At the bottom of the page.
Then I went and looked at the redrawn schematic on this site over here.http://www.diystompboxes.com/smfforum/index.php?topic=18369.0.  Hope these links work.

Thanks
Linton

[Paul Marossy]

Here are some questions I have.

1.  On the layout there is a red lead coming off the no4 pin of the tube which is 12vac.  Im not where this comes from.  Is it straight from the transformer?

2.  I have no idea where the toggle switch is on the layout or where it fits in.  I have looked on the FAQ but im unsure which is the in and out of the effects?

1. I ran that wire from the "12VAC" connection on the "power section" PCB. It essentially connects directly to 12VAC at the transformer, the PCB being the junction point.

2. Toggle switch is a bright switch which I added at a later date. I don't remember what cap value(s) I used, but if you do a search, it should come up. If you look at my PCB layout, it is on the lower left corner of the "tube/opamp section" PCB and out is off of the wiper of the 10K volume control.

[mrfirstime]

Hi Paul

Thanks thats great.  Sorry I think I mistakenly said toggle switch but what I meant was the foot switch that puts it into overdrive. ( I think its called the dpdt).  I cant seem to find that on the drawing.

Thanks
Linton

[Paul Marossy]

Oh, you mean the bypass switch. I used the "grounded circuit input true bypass" scheme found on this PDF: http://www.diyguitarist.com/PDF_Files/GCI-TrueBypass.pdf

I went with the grounded input scheme because I had a problem with my very original build when it was in bypass mode. I did this to prevent the circuit from oscillating when bypassed and somehow finding its way, faint as it was, into the bypassed signal. It wasn't a big problem, but in the right context, it would cause feedback problems.

[MikeH]

That's the first time I've seen that Paul.  I noticed how you used the input jack and bypass switch to hold the tube socket-bracket thingy in place.  Genius!

[Paul Marossy]

That's the first time I've seen that Paul.  I noticed how you used the input jack and bypass switch to hold the tube socket-bracket thingy in place.  Genius!

Gee, thanks. I consider that build one of my best ones in terms of overcoming physical challenges/constraints. Once in a while I get a eureka moment like that.  

[GibsonGM]

Like Paul said; he's actually built it! lol

[mrfirstime]

Hi Paul

Wow thanks I think I'm ready to jump in there now.  I'm sure Ill be back in a couple of weeks with my building problems but I feel positive now.  See ya soon.

Linton

[Paul Marossy]

Cool, glad I could be of some help.