Boss SD-1 Diode Clipping

[chrom-freak]

Howdy,

I have a boss sd1 and heard a lot of people saying it does sound a lot better with the c16 diode clipped.

Can anyone tell me in what direction the sound of the pedal is shaped afterwards? I heard some people saying that it does sound a lot less compressed and saturated. Is this true? I'm putting together my first pedalboard at the moment and appreciate any input. Also I'm looking into the joyo/harley benton vintage overdrive tubescreamer clone. Any opinions there?
Just too many pedals out there.

David

[Weaselcoon]

Its the C6 (capacitor). It just makes it less muffled sounding. Opens it up. I like the mod.

[waparker4]

I am not a sd-1 hotrodder (yet--picking one up this afternoon). Are you sure you don't mean C6 clipping mod. Also, c6 is a capacitor not a diode.

[bossking7]

Originally Posted by Weaselcoon

Its the C6 (capacitor). It just makes it less muffled sounding. Opens it up. I like the mod.

+1 its an amazing mod!

[czech-one-2]

Yeah, your title 'diode clipping' threw me.
Clipping the .01 C6 capacitor makes the pedal more 'transparent', clear and brighter.
A lower value cap works for me but my rig is bright already.

[chrom-freak]

Sorry for the confusion regarding the diode clipping thread title, of course i meant the c6 cap. Brain fart.

Thanks for the input everyone. I understand that it will sound less compressed and brighter afterwards, but will it sweeten up without sounding muffled when you turn down the tone knob on the pedal?

[Dr. Pants]

It doesn't make it less compressed, just brighter
and more open sounding.

[11 Gauge]

The stock value of C6 in the SD-1 is .01uF.

The role of the capacitor is to roll off treble.

In its location in the circuit, a very small value cap of 100pF or even smaller is typically standard. Also, such a cap is really only needed if there is significant clipping occurring at that part of the circuit. In this particular case, it is merely a tone circuit with a relatively small "gain factor."

Also, the part of the circuit in question is essentially equivalent to a Tube Screamer, and there is no capacitor at all in that pedal.

If anything, it is an odd sort of "redundancy" on Boss' part, because there is already treble being removed by another capacitor. I think they "messed up" with that part of the design because the SD-1 was based off the OD-1. The problem seems to be that the OD-1 had no tone control, so a capacitor to remove treble would actually be helpful. But once the tone control was implemented, Boss made the mistake of leaving the capacitor in (and I think they made its value even larger!).

Here's another way to look at it - a pedal like the OCD is capable of creating much more distortion than the SD-1, and it only uses relatively tiny 220pF capacitors in the same location. Also, the tone circuit falls after those capacitors. And something like a Big Muff uses a huge 470pF cap at each clipping stage, and it has an insane amount of distortion and clipped treble in comparison...

So even if Boss went with a .001uF cap (or what is considered 1000pF), that would still be "ten times too big" the average size of 100pF. And - something like a TS actually uses a 47pF or 51pF cap, only where the distortion/clipping occurs (in the main drive stage, NOT the tone circuit).

The bottom line is that it was primarily a design mistake on Boss' part. It's easy to forget that the OD-1 predates the TS, and when Boss rolled out the SD-1, a tone control was still a fairly new concept with many pedals.

So that's the reason why C6 presents the problem that it does.

[Weaselcoon]

Originally Posted by 11 Gauge

The stock value of C6 in the SD-1 is .01uF.

The role of the capacitor is to roll off treble.

In its location in the circuit, a very small value cap of 100pF or even smaller is typically standard. Also, such a cap is really only needed if there is significant clipping occurring at that part of the circuit. In this particular case, it is merely a tone circuit with a relatively small "gain factor."

Also, the part of the circuit in question is essentially equivalent to a Tube Screamer, and there is no capacitor at all in that pedal.

If anything, it is an odd sort of "redundancy" on Boss' part, because there is already treble being removed by another capacitor. I think they "messed up" with that part of the design because the SD-1 was based off the OD-1. The problem seems to be that the OD-1 had no tone control, so a capacitor to remove treble would actually be helpful. But once the tone control was implemented, Boss made the mistake of leaving the capacitor in (and I think they made its value even larger!).

Here's another way to look at it - a pedal like the OCD is capable of creating much more distortion than the SD-1, and it only uses relatively tiny 220pF capacitors in the same location. Also, the tone circuit falls after those capacitors. And something like a Big Muff uses a huge 470pF cap at each clipping stage, and it has an insane amount of distortion and clipped treble in comparison...

So even if Boss went with a .001uF cap (or what is considered 1000pF), that would still be "ten times too big" the average size of 100pF. And - something like a TS actually uses a 47pF or 51pF cap, only where the distortion/clipping occurs (in the main drive stage, NOT the tone circuit).

The bottom line is that it was primarily a design mistake on Boss' part. It's easy to forget that the OD-1 predates the TS, and when Boss rolled out the SD-1, a tone control was still a fairly new concept with many pedals.

So that's the reason why C6 presents the problem that it does.

Yeah. Just like I said. LOL! ; )

[coldwar1977]

simple but effective mod, and it doesnt cost one penny!!

[Rick J]

Sorry to sound like a real nerd, - but what, exactly, does "clipping out" mean here? Assuming I can locate the actual component, (advice on this welcome) do I simply snip the wire bit on one or other of the sides of the component, thus breaking the circuit its part of, or does "clipping" actually mean "jumpering" i.e soldering a bit of wire from one side of the component to the other to take it out of circuit. And where, exactly, is it, and what does it look like?

(I'm not actually that stupid, I do know what caps look like in general, I've soldered enough in and out of the control plate loom. But in this case I don't want to screw up what is already a decent enough pedal. My other reason for wanting some help in id'ing the bit is that I bought the pedal used, so its possible that the C6 cap has already been clipped, given the popularity of the mod).

Thanks in anticipation,

(the electronically challenged) Rick J

[Weaselcoon]

Originally Posted by Rick J

Sorry to sound like a real nerd, - but what, exactly, does "clipping out" mean here? Assuming I can locate the actual component, (advice on this welcome) do I simply snip the wire bit on one or other of the sides of the component, thus breaking the circuit its part of, or does "clipping" actually mean "jumpering" i.e soldering a bit of wire from one side of the component to the other to take it out of circuit. And where, exactly, is it, and what does it look like?

(I'm not actually that stupid, I do know what caps look like in general, I've soldered enough in and out of the control plate loom. But in this case I don't want to screw up what is already a decent enough pedal. My other reason for wanting some help in id'ing the bit is that I bought the pedal used, so its possible that the C6 cap has already been clipped, given the popularity of the mod).

Thanks in anticipation,

(the electronically challenged) Rick J

You can desolder it or just clip it out. Or just yank it I suppose. If I remember right its near the top of the board. It is clearly marked C6.

[waparker4]

Originally Posted by Rick J

Sorry to sound like a real nerd, - but what, exactly, does "clipping out" mean here? Assuming I can locate the actual component, (advice on this welcome) do I simply snip the wire bit on one or other of the sides of the component, thus breaking the circuit its part of, or does "clipping" actually mean "jumpering" i.e soldering a bit of wire from one side of the component to the other to take it out of circuit. And where, exactly, is it, and what does it look like?

(I'm not actually that stupid, I do know what caps look like in general, I've soldered enough in and out of the control plate loom. But in this case I don't want to screw up what is already a decent enough pedal. My other reason for wanting some help in id'ing the bit is that I bought the pedal used, so its possible that the C6 cap has already been clipped, given the popularity of the mod).

Thanks in anticipation,

(the electronically challenged) Rick J

You'd just clip one side of the component with a snipper. [ remainder edited for being wrong I think ]

[Smoky Booroo]

Originally Posted by waparker4

You'd just clip one side of the component with a snipper. [ remainder edited for being wrong I think ]

Does it matter which side you clip?

[waparker4]

Haha it's humorous that you would ask me for more info given the last bit of my post above, but if I'm not mistaken here is the schematic



and you can see that it doesn't matter, clipping either or both sides out.

[Smoky Booroo]

Haha, yes funny!

[RockerDuck]

Better to snip both ends than to desolder and cause accidental overheating that area and ruin the whole pedal.

[Rick J]

Looking at the circuit, am I right in saying that jumpering would also work? I'm thinking of ease of reversal if required, also I could take a wire from each end and make/break to hear better what the mod actually does, before making the mod permanent.

Rick J

[waparker4]

Originally Posted by Rick J

Looking at the circuit, am I right in saying that jumpering would also work? I'm thinking of ease of reversal if required, also I could take a wire from each end and make/break to hear better what the mod actually does, before making the mod permanent.

Rick J

Seems to me jumpering would cancel out R9 (10k)

[11 Gauge]

Originally Posted by waparker4

Seems to me jumpering would cancel out R9 (10k)

R9 essentially sets the gain at the op amp stage used for the tone circuit. So a jumper would basically make it like a unity gain buffer, and you would disable the tone circuit.