SD1 Switching with 3PDT Question ??

Started by HOTTUBES, March 31, 2012, 12:37:16 AM

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HOTTUBES

This will be a simple question for the pro's i'm sure .... :icon_redface:


I'm rehousing a SD1 into 1590BB along with a Boost circuit etc ...

Now the switching for the Boost i have figured out , but because the SD1 uses momentary type switch etc etc , Is it possible to
switch the SD1 with a 3PDT switch ???? I'm aware that the 3PDT is a latching switch , but is there another to control the SD1's
flip / flop on/off circuit ?





Thanks for any help !!

HOTTUBES

I ran a simple test with another Boss pedal i had on hand , i removed the boss switch and soldered the wires to a 3PDT switch ....
It will switch the circuit , but you have to cycle the switch twice to go " ON " and the same for " OFF " etc .

Could you use diodes here to control the circuit with the 3PDT ??

.Mike

Have you seen R.G.'s Technology of JFET Switching in Boss and Ibanez Pedals?

It describes how to put the pedal into always-on mode in the first five paragraphs, and then you can use regular 3PDT true bypass switching. :)

Mike
If you're not doing it for yourself, it's not DIY. ;)

My effects site: Just one more build... | My website: America's Debate.

soupbone

Quote from: HOTTUBES on March 31, 2012, 12:37:16 AM
This will be a simple question for the pro's i'm sure .... :icon_redface:


I'm rehousing a SD1 into 1590BB along with a Boost circuit etc ...

Now the switching for the Boost i have figured out , but because the SD1 uses momentary type switch etc etc , Is it possible to
switch the SD1 with a 3PDT switch ???? I'm aware that the 3PDT is a latching switch , but is there another to control the SD1's
flip / flop on/off circuit ?





Thanks for any help !!

Hey Hot Tubes.Have you ever checked this out? http://www.jackdeville.com/clickless-system/cltb  Works for Boss and Ibanez pedals.

HOTTUBES

Quote from R.G   ......


You now know all that's needed for this: you
remove the JFETs that do Sw1, Sw2, and Sw3 from the board, and insert jumpers from source to
drain where Sw1 and Sw2 used to be, leaving Sw3 out. All done.





ON the SD1 how do you identify the DRAIN & GATE of Q1 and Q2 ??

And ..

Will this mod cause the " POP " when switching etc ?

.Mike

Quote from: HOTTUBES on March 31, 2012, 11:04:57 AMON the SD1 how do you identify the DRAIN & GATE of Q1 and Q2 ??

You could either:

1. Look up the datasheet to the FETs. The datasheet certainly lists the pinout.

2. Look up the schematic. Look up the symbol for FET pinouts on schematics. Identify the D and G on the schematic. Identify what components are connected to the D and G on the schematic. Find the corresponding components that connect on the board.

QuoteWill this mod cause the " POP " when switching etc ?

Maybe. There won't be a pull-down resistor at the start of the circuit.

Mike
If you're not doing it for yourself, it's not DIY. ;)

My effects site: Just one more build... | My website: America's Debate.

HOTTUBES

Ok , so when looking at the SD1 schematic ... if i'm correct here .

remove Q2 , Q3 , Q4

Install jumper's from source to drain on Q3 & Q4

Then take the SD1's signal out to the 3PDT ....




thanks for your help here ....


.Mike

Looking at that schematic a bit closer, I think they're only using 2 of the 3 FETs that R.G. describes. I don't see a FET on the input, just two to select the output. R.G.'s SW2 would be Q1, and R.G.'s SW3 would be Q2.

I think you would want to remove Q2, the bypass path, and jumper Q1, the wet path.

Mike
If you're not doing it for yourself, it's not DIY. ;)

My effects site: Just one more build... | My website: America's Debate.

HOTTUBES

Ok Thanks MIKE   !!

I was thinking about this ALWAYS ON state of the SD1 ....
If you remove all the FETs involved in the switching of the SD1 , could you not just do a single wire
by pass some how , by picking up the effected signal at Q1 and sending it direct to the  output jack ?


And if this is possible , will there be any signal difference or loss when by passing the out put buffer ?



Groovenut

#9
...
You've got to love obsolete technology.....

HOTTUBES

Does anyone have any diagrams showing the " TRUE BY PASS " mods for the SD1 ?