Help With EHX Small Clone Mod(s)

[thefly108]

Hey everyone,

Sorry if this isn't where it should be. I'm new here, and new to pedal building/modding. I've been working on modding an EHX Small Clone, and I've been trying to mod it so the LED will blink at the same rate as the chorus effect. I've been able to do this by connecting the +9v to the first pin of one of the ICs (LM358 IC to be specific) but for some reason it also causes the wet signal to be cut out, so when the pedal powers on nothing really happens, expect for the LED lighting up. Being new to this, I'd appreciate any help since I have a very basic understanding of pedal circuitry.

Also, if anyone knows of any good tremolo or flange mods for the EHX Small Clone, I'd love to try them. Thanks.

[PRR]

Welcome.

Do this way:

[thefly108]

Welcome.

Do this way:

Interesting, thanks. So, use pin 7?

I believe I tried this earlier but without the resistor. I'll try it again. I also noticed that when I turned on a vibrato mod I added, dry signal came through anyway. If I wire this correctly, will it still work?

[PRR]

> use pin 7?

AND a resistor.

Naked LED right on a chip pin usually upsets it badly.

[thefly108]

> use pin 7?

AND a resistor.

Naked LED right on a chip pin usually upsets it badly.

I'll try that. So, should I leave the negative lead how it is (connected to the 3PDT switch)? Or should it be grounded, and if so, how should I do that? (I'm very new to this so pardon the questions).

[xorophone]

I'll try that. So, should I leave the negative lead how it is (connected to the 3PDT switch)? Or should it be grounded, and if so, how should I do that? (I'm very new to this so pardon the questions).

Do you want the LED to keep blinking when the effect is turned off?

[antonis]

I suppose that it's an indicator LED (lights when Effect is ON)..

If so, ground it to 3PDT switch as usually..

@Anton: I'm not sure if the LED can always blink - i.e if the effect is disconnected from loop chain..

[thefly108]

I'll try that. So, should I leave the negative lead how it is (connected to the 3PDT switch)? Or should it be grounded, and if so, how should I do that? (I'm very new to this so pardon the questions).

Do you want the LED to keep blinking when the effect is turned off?

No, only when it's on. I'd like it to blink at the LFO (I think that's what it is) of the effect.

[thefly108]

I suppose that it's an indicator LED (lights when Effect is ON)..

If so, ground it to 3PDT switch as usually..

@Anton: I'm not sure if the LED can always blink - i.e if the effect is disconnected from loop chain..

I wired it to the 3PDT switch and pin 7 of the IC (with a 2.2K resistor) and it gets the desired effect, but every oscillation also comes with a really loud pop (even when the effect is off).

[xorophone]

I suppose that it's an indicator LED (lights when Effect is ON)..

If so, ground it to 3PDT switch as usually..

@Anton: I'm not sure if the LED can always blink - i.e if the effect is disconnected from loop chain..

Well, I never looked at the schematic. I just assumed it would continue blinking if it was grounded at all times.

I wired it to the 3PDT switch and pin 7 of the IC (with a 2.2K resistor) and it gets the desired effect, but every oscillation also comes with a really loud pop (even when the effect is off).

I sadly don't have the knowledge to be able to help you fix this, but this will at least bump the thread.

Good Luck!

[thefly108]

I suppose that it's an indicator LED (lights when Effect is ON)..

If so, ground it to 3PDT switch as usually..

@Anton: I'm not sure if the LED can always blink - i.e if the effect is disconnected from loop chain..

Well, I never looked at the schematic. I just assumed it would continue blinking if it was grounded at all times.

I wired it to the 3PDT switch and pin 7 of the IC (with a 2.2K resistor) and it gets the desired effect, but every oscillation also comes with a really loud pop (even when the effect is off).

I sadly don't have the knowledge to be able to help you fix this, but this will at least bump the thread.

Good Luck!

Thank you! I appreciate any help at all (plus the bump).

[PRR]

> really loud pop

Return the LED to *power* ground (at the battery or power-jack), not in the midst of audio grounds.

How is the LED brightness? With modern LEDs, it may be plenty-bright. Raising "2K" to 5K or 10K may be tolerable and give less pop.

[antonis]

Alternative to Paul's suggestion (and if you insist to have a blinking LED) try to connect in series with the existing current limiting resistor another one of, say, 330R and a 10μF capacitor between the junction of the 2 resistors and GND..

It will slightly permute the On-Off real time (delay time depends on the specific RC product) but it will keep the same blinking rate..
(never done this - just an estimation..)

[pinkjimiphoton]

you're getting the popping cuz off pin 7 it's a square wave ... pin one would be a triangle wave, the difference is the tri there's less popping, and it kinda fades the led in and out. with the square wave, it's turning it off and on. i'd listen to paul on this 100%. go with a bigger resistor. and make sure the ground side of the led goes to your power ground.

usually imho it's better to leave the blinkyblinky's on all the time, and use a separate led on the bypass footswitch. that way you can always tell the modulation rate before ya kick the pedal on.

if ya wanna get a little trickier, use a bicolor led with a common anode.  connect this to a 4.7k-10 (maybe even 22k with some ultrabrite leds) to pin 7 of the lfo chip.

you'll have to look up the pinout, or experiment to find the color leads. i usually just tack on a resistor and use a battery. resistor to positive, cathode leg to battery negative. then ya can see which leg is red, which green etc.

put the green side to the "top" part of your bypass, put the red to the "bottom" of it and run the center pin to power ground.

if ya use a 3pdt wired up  like this ... will call 'em "rows" for ease of explanation


top row, left to right  board in, led green cathode, board out

middle row                audio in, led ground, audio out

bottm row                  first pin tied to third pin, middle pin led red cathode

the led will blink continuously at the rate of the lfo

in bypass it will be red (and blinky) and in active it will be green (and blinky)

may be overkill... just another way to do it. but that way ya gotta  "no-go" and a "go" led that tells ya the tempo of your modulation at all times with just one led.