DS-1 to True Bypass (3PDT)

[s.r.v.]

Hi,
Awhile ago i asked about DS-1 mods. I'm adding ten different diode clippings with toggle switches to play around with, but i also want to make it true-bypass. I have a 3pdt (of course!). I understand (a little) how the switch works, but the DS-1 circuit looks wired to me. Can someone help? thanks!

[magikker]

Are you planning on putting in to a new box? or somehow mounting the switch to the standard box.

[s.r.v.]

new box, but there were only two wires going to the switch, so how would i go about this?

[the_random_hero]

Get rid of the flip-flop switching, isolate the input and output and then wire it up for TB. If you have a schematic handy, this shouldn't be too hard to do.

[s.r.v.]

1. what is flipflop switching?
2. how do you isolate a jack?

[jonathan perez]

why? it sounds fine bypassed...

[magikker]

having the schematic would probably help. I don't think I can give any sort of good advice unless I know what I am talking about... I guess the for starters there should be wires going to and from each jack, and going to the LED. You need to locate all those.

You also need to locate the buffer to remove it. That part needs the schematic for me to help at all.

[Pushtone]

2. how do you isolate a jack?

Not the jacks but the circuit input and output points.

Everything before the circuit input and after the circuit output is the electronic bypass that you want to cut out.

Flip flop switching is just the electronic bypass part of the pedal, as opposed to mechanical bypass (3PDT switch).
Don't worry about understanding it. Just cut it out and I don't mean to physically remove the components. By "cut it out" I mean tap the circuit at the circuit input and output points.

A schematic of the pedals circuit will help a great deal in finding those tap points.

I've been meaning to do the same thing to a couple of Berhinger effects to rehouse in a metal box.



So BOTM, thats why he wants to TB it as using the stock bypass would be more trouble when rehousing a Boss pedal.

[wampcat1]

http://www.indyguitarist.com/schematics/boss/DS1PG2.jpg

[Pushtone]

Thanks for that wampcat.

Since I need to learn to do this to rehouse these Berhinger pedals I'll have a stab at it.

From that schem it looks to me like everything after Q6 and everything before Q7 is the effect circuit.

If it were me doing this I would lay the PCB on a table and solder an input jack to the conjunction of R5 and C3.
I would add a .047uF cap (to do what C13 would be doing) after R18, and solder an output jack after R18.

If it sounded OK the next step would be to cut the traces before these points.

Hows that sound to y'all?

[s.r.v.]

it sounds a tad bit confusing, but i think that i can figure it out.
how does this sound for steps:
1. locate where R5/C3 meet. attach wire to Tip or ring or sleeve of stereo jack
2. add .047uF cap from R18 to ?
3. add output jack wire from R18 to tip of mono jack
4. wire what to 3pdt?

this is still very new to me, but I really appreciate this forums help. And as far as other ds-1 mods go, ive got ten toggles lined up with clippings of: 1N914, 1N914, 1N4001, 1N34A, 3mm red LED. that all went great, so now i just have to get this 3pdt working!

[Pushtone]

I had a look at the Tonepad DS-1 project schem.
http://www.tonepad.com/getFile.asp?id=78

Looks like Fp kept Q1 at the front and Q3 at the rear in the circuit for buffering.

It may not be as easy as as stating "everything before" and "everything after".
It may take a jumper around Q6 and Q7 to keep the circuit intact.
I'm afraid its a case of the blind leading the blind here.

Anyway that business between Q4 and Q5 is the flip flop electronic bypass section that you want to cut out.

I still would try soldering leads connected to jacks to points in the circuit to find the "circuit" in and out.
Don't bother with the 3PDT until you know where to connect it.
Lets finish with the "isolation" step first. Where the circuit starts and ends.

I'll get a chance to show the schem to our repair engineer. Perhaps he can add some insight.
Although he mostly works on the Midas mixers and power amps.

As fas as your step 2 and 3....
Sorry I meant to say....

R18>>>>.047>>>>circuit out.

[wampcat1]

here you go:
http://www.indyguitarist.com/schematics/boss/ds1-truebypass.gif

I would also connect a 100pf in parallel with r5 to filter RF.

enjoy,
Brian

[Pushtone]

Thanks Brian for taking pity on srv and I.
Nice to know I was sort of on the right track.



Any benefit keeping Q1 and 3 in the circuit?


And about those Berhinger pedals of mine...
Anyone know what Boss schematic would be close to the Ultra Flanger UF100?

Boss BF2 perhaps?

[moro]

here you go:
http://www.indyguitarist.com/schematics/boss/ds1-truebypass.gif

I would also connect a 100pf in parallel with r5 to filter RF.

This is awesome. Thank you so much for posting this. You made my day.

To add to what Pushtone said, it looks like you can just remove R1, Q5, Q7, C14, and R23? I'd rather do that than cut the traces.

[s.r.v.]

  thank you so much! this is the BEST forum!
so now my last question before i turn the iron on is do you cut a trace with a knife or something?

[Pushtone]

  thank you so much! this is the BEST forum!
so now my last question before i turn the iron on is do you cut a trace with a knife or something?

Good question.

I have my Behringer PCB out of the case and I was thinking of drilling thru the trace to break it.
Of course I would only do that with a drill press.
May not be able to since the board is two sided.

In which case I would pick at it with my mini-drill tool with the pick attachment.
Its quite sharp.

[s.r.v.]

ok now all i have to do is:
1. learn to read a schematic
2. make it so i can match it up with the pcb trace
3. wire 3pdt
4. wait till monday to drill bigger holes
hope it works! thanks again

[s.r.v.]

damn this is harder than i thought!!! so far i cant really figure out where the 3pdt wires go. looking at the schematic with the 3dt, is this right:
3pdt:
123
456
789
lets say the lugs are labeled as above, in the same direction as the picture.
1. jumpered to 3
2. empty
3. jumpered to 1
4. to tip of input?
5. to ring of input
6. to ring of output
7. to R5
8. to led -
9. to R18
is this right so far? also, does the battery positive go to the ring of the input as well?

and is this correct LED wiring
lug 8 of 3pdt----->LED--->4.7k resistor-------->+ of AC jack

thanks again for all the help, i really hope i can get this working!

[moro]

damn this is harder than i thought!!! so far i cant really figure out where the 3pdt wires go. looking at the schematic with the 3dt, is this right:
3pdt:
123
456
789
lets say the lugs are labeled as above, in the same direction as the picture.
1. jumpered to 3
2. empty
3. jumpered to 1
4. to tip of input?
5. to ring of input
6. to ring of output
7. to R5
8. to led -
9. to R18

6. goes to the tip of the output, but otherwise it's correct. The output jack is mono, so it doesn't have a ring. Just a tip and a sleeve.

This is personal preference, but I also like to jumper 2 and 7. That way, the effect input is shorted to ground when bypassed.

is this right so far? also, does the battery positive go to the ring of the input as well?

No, that's the negative. The ring gets shorted to ground when you insert a mono jack. The nice thing about doing it this way is that the battery isn't connected unless you insert a jack.

and is this correct LED wiring
lug 8 of 3pdt----->LED--->4.7k resistor-------->+ of AC jack

Yes, though the value of the resistor depends on the LED and how bright you want it.