Radial bigshot ABY switcher

[bilisnegra13]

Hello folks
I need a reverse engineer, tracing master
Since my skills for doing schematics from scratch are bad I come here and ask if anyone can help with that, plus checking if all connections makes sense and to see if anyone can find the transformer substitute for this one since typing the numbers on the trafo on the web, doesn't show any successful results

Black traces are GND
RED traces are top layer and BLUE traces are Bottom layer

Electrolytic cap is non polarized

Thanks in advance

 

[PunchySunshine]

Hello folks
I need a reverse engineer, tracing master
Since my skills for doing schematics from scratch are bad I come here and ask if anyone can help with that, plus checking if all connections makes sense and to see if anyone can find the transformer substitute for this one since typing the numbers on the trafo on the web, doesn't show any successful results

Black traces are GND
RED traces are top layer and BLUE traces are Bottom layer

Electrolytic cap is non polarized

Thanks in advance

a pic of the backside of the board would help probably

 

[PunchySunshine]

datasheet for your tranny

 

[bilisnegra13]

a pic of the backside of the board would help probably

The traces are shown on the pictures with the red, black and blue traces, the real foto is just to show the transformer
Basically on the other side of the actual pcb you can just see the traces what are the red lines on the draw pcb

 

[PunchySunshine]

The traces are shown on the pictures with the red, black and blue traces, the real foto is just to show the transformer
Basically on the other side of the actual pcb you can just see the traces what are the red lines on the draw pic

I understand, but I'm not the one asking for help. Good luck!

 

[bilisnegra13]

a pic of the backside of the board would help probably

Ok ok

 

[Feral Feline]

You've got everything you need there, it would seem — the trace is done and all you need to do is make up the schematic.
It's an opportunity to hone your own skills.

I suggest checking out some ABY schematics online to help you map out your trace-to-schematic:

GGG has an ABY for sure (PDF),
BYOC's amp AB to extrapolate from,
ROG's has one with some op-amp buffers thrown in,
RG Keen too,
Others online...

 

[Feral Feline]

Found this block diagram on my HD, probably got it off the Radial website — schematic almost drawn right there for you:



The latest block-diagram on the Radial site is this one:

Brief search turned up this DIYSB thread, but you've probably already checked it out.
I've yet to read it, but may be some relevant info here, still:

BigShot ABY box: transformer?

BigShot ABY box: transformer?

www.diystompboxes.com

 

[Feral Feline]

"It's an older ABY, sir, but it checks out. I was about to trace it..."


<<I'm endangering the schematic, I shouldn't have posted here.>>


"...Should I have sold it?"












No, we can always add the LEDs...

 

[giovanni]

I kind of expected it to be buffered…

 

[Feral Feline]

I can't believe it's not buffered!

 

[Feral Feline]

There's something bugging me about all this, I can't quite put my finger on it...

Mm There are no values.

I've got a value-less rough-draught schematic drawn up and going to waste.

 

[Feral Feline]

@bilisnegra13, have you got the Bigshot's cap and resistor values for the schematic I draughted?

 

[bilisnegra13]

@bilisnegra13, have you got the Bigshot's cap and resistor values for the schematic I draughted?

Thanks for all the input and sorry for the late response

So I made a sch on my newbie skills and so it looks like right now, it's messy but somehow I followed the layout trace, I'm sure there are better ways to put a sch down

Anyone could add the 2 leds for the ab and one led for the both footswitches? Maybe?

 

[Feral Feline]

No worries about a "late response", you've been busy draughting a schematic!
Looks SO much better than mine!

I'd just add the 2 LEDs for the AB and Y footswitches while building the pedal; I'm too lazy to add it to the schematic, for now.



Here's my DIYLC amateur attempt (haven't added the values you provided, yet):

 

[Nostradoomus]

Incomplete Rough Draught, name of my next batch of homebrew

 

[Feral Feline]

Ol' Feral [reading, lips moving slowly]: "A ... B ... NORMAL"

Ol' Feral [pondering aloud to no one]: " Ah ... Ab... Abby... Abby Norm ... Mal... Hmm weird Radial-thingy... 'BigShot' — but... Y?"










I think there's something wrong with the trace/schematic.

Note the paths around C2 and R3, that R/C combo is useless because the signal will just flow right around them — path of least resistance.


EDIT: UPDATED SCHEMATIC!

 

[bilisnegra13]

Ol' Feral [reading, lips moving slowly]: "A ... B ... NORMAL"

Ol' Feral [pondering aloud to no one]: " Ah ... Ab... Abby... Abby Norm ... Mal... Hmm weird Radial-thingy... 'BigShot' — but... Y?"



View attachment 90416






I think there's something wrong with the trace/schematic.

Note the paths around C2 and R3, that R/C combo is useless because the signal will just flow right around them — path of least resistance.

I just notice this trace after finally remove those switches

 

[Feral Feline]

I just notice this trace after finally remove those switches

You've tested for continuity with a DMM?


EDIT: OKAY! I noticed an error in my schematic, and then rechecking the updated trace, the whole thing still didn't make sense.
So I re-examined the updated trace and my schematic and... well, even before the missing link was discovered, my schematic had some substantial errors — since rectified.

I was fixated on how I thought the circuit was, so failed to see how the circuit truly was — all stemming from ground around C2 and R3.
Errors fixed:

• C2&R3 were backwards, now swapped
• YSW Lug 4 went straight to ground, it does not, and it wasn't connected to LIFT 3&6
• LIFT SW 3&6 went straight to ground, they do not
• Missing trace, added

I hope I haven't missed anything else.

 

[bilisnegra13]

You've tested for continuity with a DMM?

Sure