small stone clone

[kevinparkerwannabe]

Hey, I've been playing guitar for a while and I want some new effects but where I live they're incredibly expensive, so I started looking into DIY.
I have no experience in this other than having a bit of experience soldering and slight understanding of circuitry

I saw this video and I want to make one exactly like it. How can I find schematics for it and how would I go about building one?

[bluebunny]

I can't see your video (curse my employers and their stinkin' censorship proxy!), but if you're after a Small Stone, then Tonepad has a project here.

And welcome.   

[kevinparkerwannabe]

Thanks! I was having trouble finding the PDF but now I think I have everything I need to give up  this looks too complex but it does sound amazing

[bluebunny]

It's probably not the ideal "first project".      I'd suggest starting with something relatively simple, like a one-transistor booster.  Then work your way up to stuff like the Small Stone.  That way, you'll build experience, you'll build confidence, and you'll build a small population of pedals you never knew you needed!   

[strassercaster]

It's probably not the ideal "first project".      I'd suggest starting with something relatively simple, like a one-transistor booster.  Then work your way up to stuff like the Small Stone.  That way, you'll build experience, you'll build confidence, and you'll build a small population of pedals you never knew you needed!   

I agree build a 10 component Dam red rooster and then some kind of 30-40 component  distortion pedal. I built a univibe on my third build over 100 components. I did a small cole on vero from the tagboardeffects site on my 10th build. It took me about 10 hours because i made mistakes. It sounds great though. I am going build a stereo one soon.You should be able to get a used small clone or neo clone on ebay pretty cheap. Looking back i spent 30 on parts and you can buy a real one for 50-60 on ebay.

[brunob2]

Hello everybody!

I'm trying to build the tonepad small stone on a breadboard..

Is there a general thread about this build somewhere?
I couldn't find it on the forums.

I already built the LFO and I was wondering what kind of output
to expect on an oscilloscope. I'm only having a steady 7V and something..?

Thank you guys!
b

[Mark Hammer]

There are a few obstacles to successfully building a Small Stone, chiefly, the fact that both the original chips - the CA3094 - and the substitute chips - the CA/LM3080 - are both hard to get and costly, given that they are long out of production.  So, while there may be some folks who have the inventory to build themselves a Piedrita, I would recommend against it.

That said, the Ross phaser clone - a project on the Tonepad site called the "Ropez" - is a very close replica of the Small Stone, and uses the far more available (and affordable) LM13600 chip.  For most intents and purposes, it captures 95% of what the Small Stone does/did, including the waveshaping of the LFO.

[brunob2]

Mark,
Thank you for your answer.
The fact is I already have 10 3080 I found on eBay..
I think I could really learn from this build (OTA, transistors..)
so for me it's more about the journey than the destination..

I'm just scared of burning the 3080s, as they are also quite fragile
from what I heard.

I'm gonna try it still, if I can get some more guidance,
and I'll also have a look at the Ropez..

Thank you for the info.

[bloxstompboxes]

Mark,
Thank you for your answer.
The fact is I already have 10 3080 I found on eBay..
I think I could really learn from this build (OTA, transistors..)
so for me it's more about the journey than the destination..

I'm just scared of burning the 3080s, as they are also quite fragile
from what I heard.

I'm gonna try it still, if I can get some more guidance,
and I'll also have a look at the Ropez..

Thank you for the info.

Careful, although I was lucky in my purchase of 3080s on ebay... not everyone is. They may be bad/fake and it might be hard to determine that during troubleshooting.

[Mark Hammer]

Eric makes a very good point.  I won't paint all e-bay resellers as suspect, but if the circuit ends up not firing up flawlessly first time, you're stuck with wondering about the chips, and all the effort it takes to rule them out..

Fundamentally, the art of troubleshooting is being able to check things off a list and say with confidence "Well, it couldn't be that".  And if you know you have 5 chips that might have some source-related questions, and that even if such questions don't exist there are still possibilities for frying them, that leaves more things you can't cross off the list right away.  And nobody likes making a pedal that takes months to get functioning properly.  I've been wrestling with a Mu-Tron clone that is driving me crazy at the moment, so I'm sensitive to that.

Trust me, there are better things one can do with 3080s, one or two at a time, that either can't be done with anything else, or else require too much effort and investigation to do with something else.  Save 'em for that.  Don't feel compelled to throw them at a Small Stone.

[brunob2]

Hello everyone,
I had a look at other projects and tried some fun things in the meantime, but I still have this
built on a breadboard and I am quite keen on trying it for the sake of learning.

I'm not looking at spending hours and hours on this, but as it's already built, I might
just power it on..

I'm just concerned about frying the ICs straight up.
I've powered the IC5 (LFO) and the power sectionand I was wondering if someone
would help me figuring out the voltages I'm getting:

IC5:
1- 0V
2- 6.4V
3- 6.4V
4- 0V
5- 0.67V
6- 7.1V
7- 8.5V
8- 0v

LF0: 7.1V

Q11:
1- 7.4V
2- 7.4V
3- 6.77V

Q12:
1- 7.4V
2- 6.77V
3- 7.4V

Q13:
1- 7.1V
2- 7.4V
3- 8.6V

Q14:
1- 7.1V
2- 7.1V
3- 7.4V

and

Q1:
1- 8.55V
2- 0V
3- 0V

Q2:
1- 8.64V
2- 8.55V
3- 7.64V

The rest of the circuit is not powered...I am concerned that the reading at the LFO (7V) is
way to high to be plugged into the pins 5 of the 4 other 3080s...

Any help would be appreciated!!
b

[PRR]

> concerned that the reading at

I do not see a schematic in this thread?

However 3080 pin 5 IS very sensitive. It must never go above ~~0.65V. But it is usually driven with a much higher voltage through a large resistor (10K-1Meg). Measured with a high-resistance meter and pin 5 not in circuit, the p5 feed may read a high voltage. Put a diode to ground; this is very-like what is inside 3080 pin 5. If you now get the expected 0.6?V, for the whole range of the Depth (whatever) pot, it is probably fine.

[brunob2]

Thank you for your answer!
Here is the schematics:
http://www.tonepad.com/getFile.asp?id=7

The IC5 3080 is used to generate a LFO that is gonna feed the pins 5 of the other 3080s.
I'm concerned that is reads 7V.

The pin 5 of this "LFO 3080" reads 0.65V so guess this is all good.

What did you say I should put to ground through a diode?

Thank you again,
b

[brunob2]

Hey guys,
I just dared to power up my circuit, and besides a small error,
it worked right out!
Sounds amazing too!
So anybody needs any help for their build please let me know.
Cheers,
bruno

http://cmosorchestra.com/2018/03/11/ca3080-4-stage-phaser/