Problem with SmashDrive

[GiovannyS10]

Hello guys!

I am new on this forum. I made a Smash Drive, but when i tested, the sound are very low and "stuffy". I think the problem are in the eletrolytic capacitors. What the capacitors i can use?

I used this original project.
http://www.generalguitargadgets.com/wp-content/uploads//smashdrive_lo.gif

Thanks.

[bluebunny]

Welcome.  Here's a schematic, btw:



Nothing special about those electrolytics.  Anything that will cope with the (presumably 9V) power supply will be fine.  Check out the sticky "DEBUGGING" thread at the top of this forum for what to do next.

[GiovannyS10]

Hello!

The only modification with my project is on the potenciometers. I used 200k for treble and 50k for mid. And i used a 472k instead the 0,005uF capacitor. This is my second pedal. The sound are very low.

What you think about this?

Thank you.

[Transmogrifox]

Hello!

The only modification with my project is on the potenciometers. I used 200k for treble and 50k for mid. And i used a 472k instead the 0,005uF capacitor. This is my second pedal. The sound are very low.

What you think about this?

Thank you.

Put a 50k resistor in parallel with the 50k pot, then add a 50k resistor in series with one of the treble pot (200k) legs to get the tonestack time constants something close to how it's designed. 

Your pot changes will tend to drive cutoff frequencies lower around the mids and higher around the highs.  If you do the above recommendations and it still sounds too low/muddy, then probably it is because you don't like the way the SmashDrive shapes the tone.

To get more treble and not as much low you can make the 47uF in series with drive pot to something smaller.  Try 1uF.  If it's too weak then try 10uF.  If you try several values between 1uF and 47uF you will probably find something you like better.

[GiovannyS10]

Hello!

The only modification with my project is on the potenciometers. I used 200k for treble and 50k for mid. And i used a 472k instead the 0,005uF capacitor. This is my second pedal. The sound are very low.

What you think about this?

Thank you.

Put a 50k resistor in parallel with the 50k pot, then add a 50k resistor in series with one of the treble pot (200k) legs to get the tonestack time constants something close to how it's designed. 

Your pot changes will tend to drive cutoff frequencies lower around the mids and higher around the highs.  If you do the above recommendations and it still sounds too low/muddy, then probably it is because you don't like the way the SmashDrive shapes the tone.

To get more treble and not as much low you can make the 47uF in series with drive pot to something smaller.  Try 1uF.  If it's too weak then try 10uF.  If you try several values between 1uF and 47uF you will probably find something you like better.

When i talk that the sound is low. Is not low frequency, but is low volume. When drive is on, i only hear something if i play hard in the guitar.
You want i record a sound for you hear? And when drive is turned on i only hear the sound of 6, 5, and 4 strings. But when sound is clean, i listen all strings.
What do you think about the 472k capacitor in place of 0,005 uF capacitor? Is a big problem?
Below is a pic of my board. The eletrolytic capacitor on the left are a test. I Used a 25v and 47uF capacitor. No success.



The purple wire are soldered below the board

P.S: Sorry for my english, i'm from other country.

[Transmogrifox]

472k (4700pF) is fine in place of a 0,005uF (5000pF).  That won't make the signal level low.

Maybe try first removing tone and volume and connect the 0,1 uF directly to amp/speaker output.  If all is well, then it will be VERY loud.

If it is not loud then you know something else is wrong.  Could you include a photo of the off-board wiring and also the bottom side of the PCB?  Maybe we can spot a solder bridge or broken trace.

Then make Simple Version A by connecting volume to 0,1uF output cap.  Then you will be able to adjust volume.  If you can go from quiet to very loud then that part is ok.

[GiovannyS10]

Lets go.
I'm sorry for the mess. Is because i  made some alterations search for results... no sucess.

My project is based in this image: http://www.generalguitargadgets.com/wp-content/uploads//smashdrive_lo.gif (Dont have volume pot, only drive) And dont have a .1nF. Mty version is the killer (with 3 capacitors) See the schema above.
The bottom side of the PCB  is below.
These two legs higher on the left is from a test capacitor. I will cut this.
This PCB is hand made, with pen.


Here is the pot link pic. The wire colors is like to original project (almost all).
B5K Drive, B200K Treble, B1M Bass, B50K Mid respectively.


And i dont have a 3PDT switch, and i dont found in my city. So, for replace, i use 2 Switch (6 pin) like this ( http://img.dxcdn.com/productimages/sku_128581_4.jpg ) I use this schematic for test my pedals. Always worked right. (Just solder the center terminals, and you have a 3pdt.)



The Yellow wire is from positive jack sound, and the green are negative. And other green (of center of "3PDT") wire is from 472k capacitor.
If you want, i can to remount the circuit.
Again a say sorry, my circuit is a mess because i changed he so much. Are a matted of wire.

I will try to remove these potenciometers, and say to you the result. I don't try the resistors that you spoke, because my problem is in the volume, and not in frequency.


I tried connect directly the 470pF capacitor to output. I record the sound. Are very weird, and hardly heard the treble.
First with the drive, and after without the drive (clear sound).
Setup: Guitar (Without the #5 string) > Pedal (Only Smash) > PC
Hear this: https://soundcloud.com/giovannys10/smashdriveteste-error
Are you understanding my english right?
Thanks so much, my friend.

[duck_arse]

  (I can't see any of the images. not even when I cut and paste the address from the source code.)

[GiovannyS10]

(I can't see any of the images. not even when I cut and paste the address from the source code.)

Are you talking about the linked images?

Are here, see:

This is the schematic.


This is the switch (6 pin). I glued 2 switches and made a "3PDT" soldering in the center pins.

[Transmogrifox]

Pins 2&4 are not connected to ground.  You will notice both the schematic and PCB layout have these tied together as you do, but there is a connection to ground that is missing from your board.  Add a wire from pin 4 to the ground trace and it will probably work.

[GiovannyS10]

Hello sir!

The pin 2 are connect to the ground. So, when the 3pdt is on, there is a contact with the pins 2, 1 and 4. All on the ground.
But still i will connect the pin 4 directly on ground, okay?
[...]
I made. I Connected to ground  the pins 2 and 4... Nothing happened.

OMG!

will be I will have to remake the PCB?

Transmogrifox, i saw that two 0.22uF capacitors I used ceramic capacitores, at the original project they are especified film capacitores. This is a problem? Will that I will have change the ceramic capacitors for film capacitors?

[bluebunny]

Transmogrifox, i saw that two 0.22uF capacitors I used ceramic capacitores, at the original project they are especified film capacitores. This is a problem? Will that I will have change the ceramic capacitors for film capacitors?

This won't make any difference.

[duck_arse]

giov - I see the GGG layout and the switch pic. the code below is cut from the source code for this very page, the links to your images: I can't see any of them (I'm still crying).

Code Select Expand


https://uploaddeimagens.com.br/images/000/475/810/full/DSC02454.JPG?1436909074
https://uploaddeimagens.com.br/images/000/476/022/full/DSC02458.JPG?1436934890
https://uploaddeimagens.com.br/images/000/476/024/full/DSC02461.JPG?1436935101
https://uploaddeimagens.com.br/images/000/476/025/full/DSC02462.JPG?1436935389


[bluebunny]

giov - I see the GGG layout and the switch pic.

@duck: Those two pics aren't on the Brazillian server.  Is Oz blocking Brazil?  (Does it make any difference losing the ?14385489 search arguments?  They're not needed.)

[GiovannyS10]

This won't make any difference.

And what i make now? i cant see the problem. Only this. :/
Can i try a 224k film capacitor in place that 223k ceramic?
Eu dont know what i make now. I am very sad,  never happened with me. I really want a smash drive. Already are six days with this problem.

Sadness only

P.S: The all images  are posted on Brazillian Server.

[Transmogrifox]

This is what I mean:

On the IC pins 2&4 are connected like the layout/PCB design shows, but you forgot to connect ground here.  Place  a wire where I put the red line and it will work.

[Transmogrifox]

Just noticed another problem between C2 and C3: 0,022uF caps.

Check your layout and fill in missing traces with wires.

[GiovannyS10]

Ok sir!

I got it wrong. I thought you was talking about the 3pdt not about the IC.
I will connect, but i think don't work. I think i tried make it before. If it not work, i will try to make another pcb.

Thanks for your assistance.

[duck_arse]

I see the pic relayed by transmog. I'd suggest the ohms meter to test that all the tracks are connecting as they should, or, a new pcb.

[tech_support] blue, I dunno. I try (with or) without the end stuff: with "https" it gives "Unable to complete secure transaction", with "http" instead, it give "... is currently unavailable". or is it just me?
more fooling shows I can't even have this page "https://uploaddeimagens.com/" without accepting a bad certificate. mean anything?[/tech_support]

carry on.

[Transmogrifox]

Ok sir!

I got it wrong. I thought you was talking about the 3pdt not about the IC.
I will connect, but i think don't work. I think i tried make it before. If it not work, i will try to make another pcb.

Thanks for your assistance.

As I pointed out you have at least 2 problems, so if you fix one and it doesn't work doesn't mean it wasn't the problem.  There are 2 places I noticed on your PCB that don't have a connection where the original layout has traces.  It's easier to put wires in between than make a new board.   Of course, if you want to make a new board, then make certain you have all of the traces drawn where they need to be so you don't go through this again.