Mad Professor - Stone Grey Distortion  [traced]

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TheLemon
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Post by TheLemon »

Yeah the CA3130EZ is a nice transparent sounding mosfet input based IC.
The TL051CP is to me a more focused sounding JFET input IC.

In my own builds, the CA3130EZ is nice for low to medium gain sounds with that slight vintagey sag effect. The TL051CP does this job just as well, but to me sounds suited best for low to high gain sounds, with a more modern tight sound - in the same application.

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geiristudio
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Post by geiristudio »

HEAD wrote:
geiristudio wrote: Btw, which other opamps can be used instead of TL051 ?
... that's a joke, isn't it? :D 2 posts above yours should give you a first guess. ;)
What I meant was other alternatives, that don't fit into the pattern of TL0X1.

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geiristudio
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Post by geiristudio »

I've built the vero and it works. However I used TL071 instead of TL051. I don't know if there's a big difference between them. I didn't like how the pedal was almost fuzzy so I changed to 2n7000 and it sounds very good now! That's all I've changed, so everything else is according to the vero.

The output of the pedal is extremely high. Even with the volume turned to 9 o'clock, it's way too high. How can I fix that ?

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Seiche
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Post by Seiche »

try lowering R9 to 470k

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geiristudio
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Post by geiristudio »

Nope, didn't work. I've tried R1 and that doesn't much. Changing R9 to 470 makes it soft and the gain knob doesn't do much anymore. Still a bit loud.

Any other suggestions ?

I just want nominal level when it's at 12 o'clock. The active signal is soooo much louder than the bypassed one. It's not supposed to be like that. Am I the only one experiencing that ?

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Seiche
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Post by Seiche »

what if you increase R12? might mess up the tone control though.
I dunno, you need a resistor somewhere lowering the output, R12 might not be the ideal place for it though, you might have to change the cap of the LPF.

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geiristudio
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Post by geiristudio »

Seiche wrote:what if you increase R12? might mess up the tone control though.
I dunno, you need a resistor somewhere lowering the output, R12 might not be the ideal place for it though, you might have to change the cap of the LPF.
I'll try it! Which cap is that and should I increase the cap value ?

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Seiche
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Post by Seiche »

geiristudio wrote:
Seiche wrote:what if you increase R12? might mess up the tone control though.
I dunno, you need a resistor somewhere lowering the output, R12 might not be the ideal place for it though, you might have to change the cap of the LPF.
I'll try it! Which cap is that and should I increase the cap value ?
It's the cap on the tone control: C12

Image
So if you increase R12, you should lower C12 by the same proportion to leave the frequency the same.

Not sure if this works though, maybe someone with more knowledge should chime in.

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geiristudio
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Post by geiristudio »

I left everything like the schematic but changed R12 to 1M (friggin' huge step!)

I tried 510k and that wasn't right so the next value I had was 1M. With 1M the volume is about the same when the volume knob is maxed out. So I'm guessing that somewhere in between 510k and 1M should do the trick.

For me, the pedal sounds friggin' nice now with the 2N7000!

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Seiche
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Post by Seiche »

so you didn't change the cap?

awesome that it worked for you!

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geiristudio
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Post by geiristudio »

Nope, didn't change it! It does not suffer any tone loss. I like how it sounds now. It's not really the same anymore but is what I was looking for. :D

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pollyn
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Post by pollyn »

hi all,
I built this pedal using the vero layout.
I'm using ca3130e opamp.
The problem is that when i tunt the pedal on, there is no distortion sound, it's almost like my clean sound :?
I'm pretty sure i didn't make any mistakes building it..
When i turn the distortion pot, there is almost no different in sound.
When turning the tone pot, there is less or more trebble i think.
What could be the problem??
I hope someone can help me out..

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Post by grrrunge »

pollyn wrote:The problem is that when i tunt the pedal on, there is no distortion sound, it's almost like my clean sound :?
I'm pretty sure i didn't make any mistakes building it..
I'm pretty sure you did make any mistakes building it.
I built it from the vero layout as well, and mine is loud and angry as fuck...

Try posting images of both component and track side of your build ;) I'll be happy to have a look at it for ya'...
A true believer in the magic of Sherwood Forest Pedal Pirates
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roseblood11
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Post by roseblood11 »

measure the voltages at both ic's

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pollyn
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Post by pollyn »

aight,
I measured voltage at both ic's:

CD4069
7,25V between 14:vdd(+) and 7:vss(-)

CA3130e
7,25V between 7 (+) and 4(-)

Here are some pictures of the circuit
The blue wire at the back was one i forgot but the socket was already soldered in..
Image
Image
Image
Image

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Seiche
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Post by Seiche »

pollyn wrote:aight,
I measured voltage at both ic's:

CD4069
7,25V between 14:vdd(+) and 7:vss(-)

CA3130e
7,25V between 7 (+) and 4(-)
no, "measuring the voltages of the ic" means you measure the voltage of each pin of the ic vs. gnd. so your black wire goes to ground and the other one touches each pin.
then you write them down for each pin starting at 1 (that is where the little circular dent in the IC is).

also take a box cutter and scrape between the traces and make sure all the trace cuts are properly cut (no copper residues shorting them)

Also it looks like you forgot the two jumpers to the right of the CD4069 (IC1), the ones that have "Attenzione" written next to them on the vero. :mrgreen:

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pollyn
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Post by pollyn »

o, sorry, i tought the supply voltage.
so, the CA3130E:
1 : 0,03V makes a tweeting sound whe i measure.
2 : 5,34V
3 : 1,84V makes buzzing sound when i measure
4 : 0
5 : 0,44V litlle bit noise when i measure
6 : 5,72V
7 : 7,23V
8 : 2,28V little bit noise when i measure

The CD4069:
1 : 3,08V makes noise when i measure
2 : 3,15V
3 : 7,22V
4 : 0
5 : 2,88V silent when i measure (even when playing guitar)
6 : 3,15V
7 : 0
8 : 0
9 : 7,21V
10 : 0
11 : 7,21V
12 : 0
13 : 7,21V
14 : 7,21V

Also, when i disconnect the power, the output is a tweet that goes from high to low frequency and after a second or so it's just a popping sound, slower and slower.

I really don't know what the problem is.. I looked over everything twice, probably i look over the mistake. Or there is a broken component??

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pollyn
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Post by pollyn »

Damn, i found something..
Image
Image

As you see in the pictures, lane K and L were connected at pin 6...
I fixed it but there is no difference in the sound, still almost like my clean sound :hmmm:
Did i burn broke some components with this mistake?
Seiche wrote:
Also it looks like you forgot the two jumpers to the right of the CD4069 (IC1), the ones that have "Attenzione" written next to them on the vero. :mrgreen:
No, the connection is there, but you can't see it in the pictures, sorry for that

O, and Pin 5 from the CA3130E is 0,04, not 0,44

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suicidemachine
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Post by suicidemachine »

ok. I have CA3130ez ,TL071 and TL081.The CA3130ez not work for me too, It get clean sound.But TL071 and TL081 it work very well.

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geiristudio
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Post by geiristudio »

suicidemachine wrote:ok. I have CA3130ez ,TL071 and TL081.The CA3130ez not work for me too, It get clean sound.But TL071 and TL081 it work very well.
I recommend using TL071 and change to 2N7000 or 2N5088. I like 2N7000 more.

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