Tubescreamer clean and clip Project

[preciousmolina666]

THE DRIVE SECTION:
The unclipped affect by 51p and .047 (the low pass and high pass)
and Does the clipped also???
im going to build seperate so i have control   

[EBK]

THE DRIVE SECTION:
The clean affect by 51p and .047 (the low pass and high pass)
Does the clipped also?
im going to build seperate so i have control   

I was following along fine until just after "Tubescreamer", but I can tell you are excited, and I love a mystery, so build away and report back. 

[patrick398]

I had to double check it wasn't a Haiku 

[preciousmolina666]

I had to double check it wasn't a Haiku 

who's haiku 

[patrick398]

I had to double check it wasn't a Haiku 

who's haiku 

Haha it's a type of Japanese poem...when i read your first post it kind of sounded like one in my head haha

[EBK]

I had to double check it wasn't a Haiku 

who's haiku 

Haha it's a type of Japanese poem...when i read your first post it kind of sounded like one in my head haha

1uF
Electrolytic or film
For blocking DC

[patrick398]

I had to double check it wasn't a Haiku 

who's haiku 

Haha it's a type of Japanese poem...when i read your first post it kind of sounded like one in my head haha

1uF
Electrolytic or film
For blocking DC

Hahahaha Superb! 

[patrick398]

Printed circuit board
Components connected there
Together at last.

[EBK]

preciousmolina666, if you want to put this thread back on the rails by giving us more information on what you are planning to build, we'd be happy to give you more meaningful feedback.  We really do enjoy helping others around here.

My apologies in advance, as I can't resist adding one more haiku:

I used dirt cheap parts
Home-etched phenol resin board
Please help me debug

[patrick398]

Hahaha, maybe someone should start a separate thread for electronics based Haiku's. They're funny but certainly not very helpful haha

[preciousmolina666]

hahaha ive search haiku poem now i get it  , ive seperate it for question1, question2 and why.
back on topic, im going to build a sepearate tubescreamer, one with diode and the other is without.
in the drive section of tubescreamer signal works in parallel. the first signal is amplified and the other is clipped by diode.
i want to know if the two signal are being low pass and high pass.

[EBK]

hahaha ive search haiku poem now i get it  , ive seperate it for question1, question2 and why.
back on topic, im going to build a sepearate tubescreamer, one with diode and the other is without.
in the drive section of tubescreamer signal works in parallel. the first signal is amplified and the other is clipped by diode.
i want to know if the two signal are being low pass and high pass.

I'd recommend reading R.G.'s Technology of the Tube Screamer article for more insight as to how this circuit works: http://www.geofex.com/Article_Folders/TStech/tsxfram.htm

The short answer to your question, if I understand it correctly, is yes, the signal would still be filtered if the diodes were removed.

[EBK]

By the way, without the clipping diodes, you'll still get clipping by the op amp due to the high gain.  It may or may not be to your liking.  Overall, the output will be much louder without the diodes.

[idy]

Sounds like our amigo wants to build a "Klon," with seperate paths for clipped and unclipped, each with different eq, then mixed...
I remember reading how in a TS type circuit there is still a (unity gain?) unclipped signal present leaving the clipping stage... Maybe that's what he is after...
Try googling "Tube Screamer's Secret" for this line of reasoning.

[EBK]

Sounds like our amigo wants to build a "Klon," with seperate paths for clipped and unclipped, each with different eq, then mixed...
I remember reading how in a TS type circuit there is still a (unity gain?) unclipped signal present leaving the clipping stage... Maybe that's what he is after...
Try googling "Tube Screamer's Secret" for this line of reasoning.

I'm wondering if we are instead talking about whether the buffered bypass path is filtered.... 

That Tube Screamer's Secret stuff makes my brain uncomfortably itchy.  The explanation is too hand-wavy.  I'm going to have to sit down with pencil and paper and work out the math myself to figure out if I should be learning something new or actively ignoring something that doesn't appear to make sense.

[ashcat_lt]

The "lowpass" is actually a shelving highpass:

While the "highpass" is a shelving lowpass:

In which R1 (for both) is the parallel combination the drive pot and the effective resistance of the diodes.  The fun part being that the effective resistance of the diodes changes based on the instantaneous level at the opamp output.  (the even more fun part being that this level is completely dependent on that effective resistance which depends on it :/)  If you imagine the diodes as a straight wire, you'll see that those filters won't really do anything.  It'll be essentially flat.  So for the portion of the signal swing where the diodes are conducting, the filters really can't be doing anything. 

That Tube Screamer's Secret stuff makes my brain uncomfortably itchy.  The explanation is too hand-wavy.  I'm going to have to sit down with pencil and paper and work out the math myself to figure out if I should be learning something new or actively ignoring something that doesn't appear to make sense.

Yeah, it's not really very deep, and doesn't explain particularly well, but really is pretty close to the truth.  In fact, it's pretty much exactly the way I ended up coding my TS-style plugin.

[EBK]

Yeah, it's not really very deep, and doesn't explain particularly well, but really is pretty close to the truth.  In fact, it's pretty much exactly the way I ended up coding my TS-style plugin. 

For those of you following along, here is a link to the TS "Secret" article:

http://www.bteaudio.com/articles/TSS/TSS.html

The part that bugs me the most is where it says that the amplified portion gets clipped softly at the diode forward voltage (fine), but the combined signal gets hard clipped at the op amp rails (wait a minute).
It seems like if this is happening, you would be chopping off that soft clipped portion unless you were just barely at the op amp's limit.  The article goes on to say that somehow, despite hard clipping at the rails, input dynamics are supposedly preserved at the output (my brain screams "not a chance!" at this point).  You'd have a hard-limited output with a fixed maximum voltage depending essentially only on your rail voltage, right?  What am I missing?

[ashcat_lt]

You'd have a hard-limited output with a fixed maximum voltage depending essentially only on your rail voltage, right?  What am I missing?

Once the diode "opens up", the output is essentially the input plus the forward voltage of that diode.  It's only actually going to clip the opamp if the input is already within a diode drop of however close to the rail that opamp will get to it.  Most guitars aren't that loud, but if you start boosting things ahead of the TS...

The take away should be that this circuit is functionally almost exactly the same as if you built it as a diode-to-ground distorter and then mixed in the original signal at unity except that the diode-to-ground version would be more likely to clip the opamp.

To the OP - it's still hard to say what exactly you're asking.  The part of the signal that exceeds the diode drop is not really filtered, but if you take out the diodes, that signal will be.  Whether that's what you want is completely up to you.  I think it's more likely they will sound more similar if the "clean" one is filtered, but...

[stringsthings]

those haiku's are hilarious!! 

My Tube Screamer build
Clouds and Puffs of Magic Smoke
Tears and Tears Falling

[EBK]

The take away should be that this circuit is functionally almost exactly the same as if you built it as a diode-to-ground distorter and then mixed in the original signal at unity except that the diode-to-ground version would be more likely to clip the opamp.

That is the one cool thing I did take away from the article: the "1" in "A_v = 1 + R₂/R₁" is actually special when you have a non-linear feedback loop.  For that I am thankful.