"String Dampener" circuit

mich · Post by **mich** » 24 Apr 2011, 00:01

So somewhere along the way searching for ideas for pedals online, I came across this article:

StringDamper.pdf: article; (202.57 KiB) Downloaded 364 times

Seemed like a neat idea but no idea how it would sound or even work once assembled. Anyways, i did a layout for the circuit (had to use two jumpers, pissed but I really don't see a lot of freedom when working up layouts for DIPs with 16 pins (the jumpers are shown in red, i mock them up as the top layer in Eagle):

: transfer

: layout_Key

And here's the partlist:
Part Value Package Library Position (mil) Orientation

+9V1 +9V(T) SQUARE gm-supply (1550 200) R270
ATTACK 470KA POT gm-pots (825 1425) R90
C1 47n 070X030_3 gm-caps-film-chicklet (425 1000) R270
C2 22u 050_020_2 gm-caps-electro-pol (1200 975) R0
C3 33p 070X030_3 gm-caps-film-chicklet (1125 1500) R0
C4 22u 050_020_2 gm-caps-electro-pol (1450 700) R270
C5 22u 050_020_2 gm-caps-electro-pol (1625 1550) R180
C6 2N2 070X030_3 gm-caps-film-chicklet (1975 1225) R270
C7 47n 070X030_3 gm-caps-film-chicklet (1725 1250) R270
C8 22u 050_020_2 gm-caps-electro-pol (1150 1250) R270
C9 2U2 050_020_2 gm-caps-electro-pol (675 1262.5) R270
D1 LED5MM LED5MM gm-diodes (1200 450) R270
D2 LED5MM LED5MM gm-diodes (1550 450) R90
D3 1N4148-3 DO35-3 gm-diodes (2375 925) R90
D4 1N4148-3 DO35-3 gm-diodes (2375 1400) R90
D5 1N4148-3 DO35-3 gm-diodes (2275 1400) R270
D6 1N4148-3 DO35-3 gm-diodes (1850 1325) R90
DECAY 470KA POT gm-pots (812.5 1737.5) R90
GND2 GND(T) SQUARE gm-supply (250 100) R180
IC1 TL072P DIL08 gm-ics (1450 1250) R270
IC2 LM13600N DIL16 synthdiy (1375 2125) R270
IN SQUARE gm-supply (250 350) R180
OUT SQUARE gm-supply (250 500) R180
R1 220k R0207/4 gm-resistors (537.5 1025) R90
R2 220k R0207/4 gm-resistors (975 1800) R90
R3 680R R0207/4 gm-resistors (1500 1675) R0
R4 4k7 R0207/4 gm-resistors (1850 1775) R270
R5 2k2 R0207/4 gm-resistors (1925 750) R180
R6 4k7 R0207/4 gm-resistors (1375 325) R90
R7 4k7 R0207/4 gm-resistors (1675 400) R90
R8 1M R0207/4 gm-resistors (1675 2275) R90
R9 10K R0207/4 gm-resistors (1925 975) R180
R10 1M R0207/4 gm-resistors (2275 950) R90
R11 4K7 R0207/4 gm-resistors (500 1612.5) R180
R12 270R R0207/4 gm-resistors (500 1487.5) R180
R13 4K7 R0207/4 gm-resistors (2175 1325) R270
R14 1M R0207/4 gm-resistors (2087.5 1325) R270
R15 10K R0207/4 gm-resistors (1075 1975) R90
R16 4K7 R0207/4 gm-resistors (875 2275) R270
R17 10K R0207/4 gm-resistors (900 1075) R180
R18 4K7 R0207/4 gm-resistors (1075 2475) R270
R19 4K7 R0207/4 gm-resistors (975 2350) R270
R20 10K R0207/4 gm-resistors (1800 2275) R270
R21 2K2 R0207/4 gm-resistors (775 2200) R270
R22 4K7 R0207/4 gm-resistors (975 850) R0
STOMP 3PDTBLUE CHINABLUE gm-switches (700 450) R0
SW1 DPDT DPDT gm-switches (2050 450) R90

I haven't put it together yet as I'm studying for my medical boards but if someone has the chance and inkling to put one together I'd be interested in the results. Thanks

Hides-His-Eyes · Post by **Hides-His-Eyes** » 24 Apr 2011, 00:17

You can shrink the DIP pads and run traces between the pins... Not ideal, but jumpers hurt, don't they?

Tonetweaker · Post by **Tonetweaker** » 26 Apr 2011, 03:18

mich wrote:Seemed like a neat idea but no idea how it would sound or even work once assembled.

A "String Dampener" effect is the principle behind the ISP Decimator, if I remember correctly. I think it's supposed to even out the sound of the "G" string specifically (I believe?). Perhaps someone could back me up on that, though. My memory ain't what it used to be.

mictester · Post by **mictester** » 26 Apr 2011, 05:28

Tonetweaker wrote:
mich wrote:Seemed like a neat idea but no idea how it would sound or even work once assembled.
A "String Dampener" effect is the principle behind the ISP Decimator, if I remember correctly. I think it's supposed to even out the sound of the "G" string specifically (I believe?). Perhaps someone could back me up on that, though. My memory ain't what it used to be.

No - it's similar to the "Slow Gear", but with attack and delay controls. It was meant to be "normally off", but enabled for the occasional note with a momentary footswitch. It's not a bad implementation, but is designed not to be bypassed. It sounds really interesting before a Big Muff Pi, getting the notes to build into distortion. I used it on a couple of tracks on an album back in the early 90s.

borislavgajic · Post by **borislavgajic** » 26 Apr 2011, 22:10

I have made it 5 years ago......interesting......but ....you must wait decay to finish....it does not stops and reset when you stop playing......slow gear does.......
it would be great to make combination

boris

Tonetweaker · Post by **Tonetweaker** » 27 Apr 2011, 03:09

mictester wrote:
Tonetweaker wrote:
mich wrote:Seemed like a neat idea but no idea how it would sound or even work once assembled.
A "String Dampener" effect is the principle behind the ISP Decimator, if I remember correctly. I think it's supposed to even out the sound of the "G" string specifically (I believe?). Perhaps someone could back me up on that, though. My memory ain't what it used to be.
No - it's similar to the "Slow Gear", but with attack and delay controls. It was meant to be "normally off", but enabled for the occasional note with a momentary footswitch. It's not a bad implementation, but is designed not to be bypassed. It sounds really interesting before a Big Muff Pi, getting the notes to build into distortion. I used it on a couple of tracks on an album back in the early 90s.

I stand corrected. I didn't take the time to look at the schematic, so I thought he was referring to a noise suppression circuit. Apologies.

mictester · Post by **mictester** » 27 Apr 2011, 05:14

borislavgajic wrote:I have made it 5 years ago......interesting......but ....you must wait decay to finish....it does not stops and reset when you stop playing......slow gear does.......
it would be great to make combination

boris

Mine re-triggers reliably on every new note. Perhaps yours was broken, or you use really "hot" pickups, or you tried to use it after a distortion box that destroys the dynamics of your playing! It works best if fed straight from the guitar. However, I put a "sensor" input on it, to look at the "un-effected" guitar signal, but the audio path of the device could be put later in the effects chain. This mod makes the pedal really flexible. If anyone's interested, I'll post the mods.

reneshelle · Post by **reneshelle** » 27 Apr 2011, 09:29

I'm thinking about building this one. Sounds fun.

@Mictester. I would like to see how you did the mod to yours. Opens up a whole lot of options. Triggering from another signal than your guitar or triggering other things with your guitar....

mictester · Post by **mictester** » 27 Apr 2011, 11:16

reneshelle wrote:I'm thinking about building this one. Sounds fun.

@Mictester. I would like to see how you did the mod to yours. Opens up a whole lot of options. Triggering from another signal than your guitar or triggering other things with your guitar....

Correct!

I'll dig out the drawings later today. I also did a PCB for this one, incorporating a few small modifications.

reneshelle · Post by **reneshelle** » 27 Apr 2011, 20:57

Thanks. I'm thinking of doing it on vero or perf. You do not have to search hour after hour for the pcb. At least not for me to see. Have never done any etching myself. I do teach chemistry though! The irony is obvious...

But a schemo-thingy would be nice.

Cheers

René

borislavgajic · Post by **borislavgajic** » 06 May 2011, 11:29

mictester wrote:
borislavgajic wrote:I have made it 5 years ago......interesting......but ....you must wait decay to finish....it does not stops and reset when you stop playing......slow gear does.......
it would be great to make combination

boris
Mine re-triggers reliably on every new note. Perhaps yours was broken, or you use really "hot" pickups, or you tried to use it after a distortion box that destroys the dynamics of your playing! It works best if fed straight from the guitar. However, I put a "sensor" input on it, to look at the "un-effected" guitar signal, but the audio path of the device could be put later in the effects chain. This mod makes the pedal really flexible. If anyone's interested, I'll post the mods.

Pickups are hot...humbackers from Gibson.......I will put it together again just to see how it works.......
thanks mictester...it would be great to see your modifications

Boris

reneshelle · Post by **reneshelle** » 14 May 2011, 14:23

I've done a vero. I have checked it, and double checked it - but not build it yet. It might be some time before I get around to building it. So as for now it is not verified. I've made it true bypass and without any sidechain option. I might do a sidechain version at some time...

It's done with StripMagic and I've attached the .diyx file

You need to connect the two rows labeled *WIRE1* with a wire. Same goes for *WIRE2*

9v+ is called +v in the schematic and battery-ground is called -v. The ground (it's actually +4.5v) in the schematic is not connected to the battery.

Cheers

reneshelle · Post by **reneshelle** » 14 May 2011, 19:06

^^ I just looked at the tracecut template and I have no idea why C1 is marked... No tracecuts at those two points!!!!

reneshelle · Post by **reneshelle** » 22 May 2011, 15:08

I have now build it and the layout worked.

Boris mentioned that he had to wait for the decay to finish before it would retrigger. Mine will retrigger during the decay fase. I do however have to wait for the attack to finish before the decay kicks in. This is very annoying! Maybe I just have to learn to "play the effect", but I was going for a swell pedal and this is not it...

I have not put it in a box, and I don't think that I ever will. I have thought about digging into the circuit and doing some mods to it. But I don't think I will. I kinda get the idea from the schemo, but to be frank, I don't really know how it works. This one was mostly a paint by numbers kinda build for me.

~arph · Post by **~arph** » 22 May 2011, 16:08

reneshelle wrote:^^ I just looked at the tracecut template and I have no idea why C1 is marked... No tracecuts at those two points!!!!

Yeah, that's a bug

BTW, if you give the resistors the right values the colored bands will show up.. helping people building it

reneshelle · Post by **reneshelle** » 22 May 2011, 16:31

~arph wrote:BTW, if you give the resistors the right values the colored bands will show up.. helping people building it

I know, but for a guy like me who is partial red-green colourblind that is really the opposite of help!

If I'm tracing something I'm constantly asking my wife...

But thanks anyway