EHX - Small Stone ( LM13600 )  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

Re: EHX - Small Stone ( LM13600 )

Postby mecmast » 14 Sep 2015, 13:07

minnow wrote:Hi everyone. Some updates on this.
I have built this according to the layout (not the schematic values, refer to notes):

1. 1K8 on layout (vs 1K on schematic)
2. 100 on layout (vs 100K on schematic)
3. 33uF capacitor polarity (polarity follow schematic, not the layout)
4. 47nF cap connects LM324 pins 1 & 4 on layout (vs pins 5 & 7 on schematic)

It works! Great sounding phaser (coming from someone who dislike phaser effect).

However, there is a kind of "noise" that happens during the trebly end of the sweep (swirl). Like a flourescent lamp "eeeeeeek" noise.
When the sweep (swirl) is on the dark side of the moon, noise is not present / noticeable.
Hope my explanation is not too confusing.
This is noticeable in both switch positions. The position with deeper sweep has more noticeable "noise".

I have tried this effect without the guitar plugged in, meaning the pedal outputs directly to the amp, with a battery.
So ruled out my guitar pickups causing this problem.
I turned off my lights, turned off computer monitor (unplugged from mains) and tried the amp on two different power mains.
The amp is quiet with other pedals.

During my build, every component measured prior to soldering, and measured for contact after soldering.
STILL, probably a build error from my side.
But any help / clue on what to look out for will be great.

Could it be switch wiring error?

One more thing, when I unplug the guitar cable to the pedal, one switch position howls and squeals. Plug in again and it's gone.

I hope anyone else who has built it or anyone working on this can chime in and get this project in FSB going.
As always, thanks everyone!


Hi have you solved the "noise" issue?

I'm gonna try to build this one but i'm afraid of the same problem.

Has anyone else build this pedal? I really need comments.

Also i've a question. I couldn't find 2n5088. Shall i use BC239 instead? Or any suggestions?

Thank you.
mecmast
 
Posts: 46
Joined: 29 Aug 2008, 13:40
Has thanked: 8 times
Have thanks: 2 times

Re: EHX - Small Stone ( LM13600 )

Postby mecmast » 26 Sep 2015, 19:20

I've obtained the 2n5088's. Ready to build. But still need comments.

Thank you.
mecmast
 
Posts: 46
Joined: 29 Aug 2008, 13:40
Has thanked: 8 times
Have thanks: 2 times

Re: EHX - Small Stone ( LM13600 )

Postby minnow » 28 Sep 2015, 06:52

Hi Mecmast,
I've not solved the issue with my build. It is still as it is.
You could try building it. Perhaps it is an error in my build, and you could make it through fine? :)
Go for it!
User avatar
minnow
Breadboard Brother
 
Posts: 146
Joined: 30 May 2010, 04:51
Has thanked: 26 times
Have thanks: 18 times

Re: EHX - Small Stone ( LM13600 )

Postby Haradax » 27 Oct 2015, 13:40

Hello people!
Although for a while I was sneaking around here, this is my first post, and I'm sorry for my bad English. (blame the translator, Mr.G.) :)

Thanks to everyone on this topic who helped in making this nice layout, by which I made my biggest PCB so far.
Today I soldered elements and temporary wires, and with skepticism plugged it between guitar and the little amplifier.
Vow... It started working immediately.
Maybe it's just a first impression but it sounds great, better than my proud "phase 90" made last year.
After a bit of playing I found small issues, the same, or almost the same kind described by user minnow.
It occurs when the effect is in bypass mode while the switch is in the "ON" position by the scheme ("bright side", the higher tone). The problem disappeared when I put in front some buffered pedal. As Mininow, I also suspect that the problem is around the "color" button. Or maybe a different bypass wiring (grounding input in bypass mode) can fix this little problem.
Today I will try to solve that, and write the results here, of course.

Regardless of the problem, effect is very useful. Although, if I do not fix this phasing whistling, though this effect will surely find it's place in my pedalboard. Anyway I prefer the "darker color" mode which works fine, so there is no problem at all. :wink:
image:
Image
You can see two 1M trimmers on the little black breadboard which acting 2M pot before mailman arrives from China.

As mentioned this is my biggest self etched PCB made using iron/toner-transfer method, and certainly the most beautiful one. I have changed changed layout a little, nothing significant, just to make the PCB a bit smaller. I'll try to squeeze it in 125B.
Image

P.S.
I have basic knowledge in electronics, and so far I have successfully made about 18 pedals for about two years, how long been doing this addictive hobby. Some of those you can see here.
User avatar
Haradax
 
Posts: 6
Joined: 04 Feb 2014, 04:55
Has thanked: 8 times
Have thanks: 1 time

Re: EHX - Small Stone ( LM13600 )

Postby minnow » 29 Oct 2015, 04:48

Hi Haradax,
Nice layout! And thanks for updating.
I've not done anything yet to my build :(

Regarding the component values - did you use the schematic ones or the from the layout?

For this message the author minnow has received thanks:
Haradax (30 Oct 2015, 09:07)
User avatar
minnow
Breadboard Brother
 
Posts: 146
Joined: 30 May 2010, 04:51
Has thanked: 26 times
Have thanks: 18 times

Re: EHX - Small Stone ( LM13600 )

Postby Haradax » 30 Oct 2015, 09:06

minnow wrote:Hi Haradax,
Nice layout! And thanks for updating.
I've not done anything yet to my build :(

- did you use the schematic ones or the from the layout?

Thank You, mininow.
Regarding the component values, I used layout one ( small exceptions: for 1uF output cap. I choose film one, and also 3x tantalum instead of electrolytic, see pic.)

Good news is that I have fixed the whistling issue (by LFO) heard in bypass mode. As I intended, different wiring of 3PDT (grounding the input) has solved a thing.
As for me, this nice phaser is verified. :horsey:

Now i have one small sweet problem. On the PCB I've etched two words for the name of pedal, but I can not choose would I name it "Smile Stoned" or "Stoned Smile"? :scratch: Please help me people!
User avatar
Haradax
 
Posts: 6
Joined: 04 Feb 2014, 04:55
Has thanked: 8 times
Have thanks: 1 time

Re: EHX - Small Stone ( LM13600 )

Postby stnky1 » 20 Nov 2015, 06:52

Hey all:

I'm gonna try building this one eventually...has anybody been able to source the proper 2Meg rev. audio (2MC) pot or are you just using linear taper?

I tried all my usual suspects (Smallbear, Tayda, Sayal, Digikey, Mouser etc...) and can't seem to find one.
stnky1
 
Posts: 1
Joined: 18 Nov 2015, 06:51
Has thanked: 0 time
Have thanks: 0 time

Re: EHX - Small Stone ( LM13600 )

Postby Haradax » 20 Nov 2015, 20:38

stnky1 wrote:Hey all:

I'm gonna try building this one eventually...has anybody been able to source the proper 2Meg rev. audio (2MC) pot or are you just using linear taper?

I tried all my usual suspects (Smallbear, Tayda, Sayal, Digikey, Mouser etc...) and can't seem to find one.

Hi.
Neither I haven't found the right pot.
I put one of 2.2M lin. found on ebay. Responding to the speed change is not linear as it should be, but it can be used.
When you do not have right 2M rev.log. here it is better to be a some larger resistance.
We can also try to find 2M log. pot and wired it opposite.
User avatar
Haradax
 
Posts: 6
Joined: 04 Feb 2014, 04:55
Has thanked: 8 times
Have thanks: 1 time

Re: EHX - Small Stone ( LM13600 )

Postby Haradax » 06 Oct 2017, 16:06

One month ago I finally squeezed this one into 125b box.

Image Image
That big pot in the photo is the wirewound 2.2M Lin from e-bay. (rheostat :D)
Meanwhile I found more suitable potentiometer, a CTS 3M Rev-log at musikding.de.
It can be used as it is, or with a 6.8M resistor in parallel to get exactly 2M. The taper stays almost the same.

Image

For this message the author Haradax has received thanks:
Nocentelli (08 Oct 2017, 10:28)
User avatar
Haradax
 
Posts: 6
Joined: 04 Feb 2014, 04:55
Has thanked: 8 times
Have thanks: 1 time

Previous

Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: No registered users and 11 guests

cron