The boss Boss PH-2 mode switch what does this mode switch do? is it feedback paths? i don't have the schematic so i don't know where the paths of this mode switch does
The small stone "colour switch" what does this do in the LFO circuit? it seems to change the LFO circuit but what does the colour switch do to the LFO?
The Boss PH-3 has a rise and fall time for the LFO how did they do this? putting a diode on the output of the LFO to just get the rise?
Whats unidirectional phasing?
Does the "colour switch" change the DC offset in the small stone LFO?
> Does the "colour switch" change the DC offset in the small stone LFO?
From my notes: It makes the sweep wider. ie the notches start at lower frequencies and move up to high frequencies compared to the normal mode. As a side effect the sweep rate is a little slower.
Thanks for the information
how does it change or make the sweep wider?
How would i change a MXR phase 90 LFO to get the sweep wider like the small stone "colour switch"?
The colour switch must change the sweep range? but how does it do this?
It does not make the sweep wider, as far as I know. It only introduces feedback to make the peaks "peaker" and incidentaly, also changes the lfo speed range (slower?)
Miguel
it`s a 2pdt switch: 1p increases LFO output amplitude,
the other switches on audio FB.
introduces feedback to make the peaks "peaker"
It increases the feedback peaks in the LFO? how does it do this please?
How does the "colour Switch" increase the amplitude? is it extra gain in the LFO circuit?
Quote from: puretube on December 29, 2005, 02:14:02 PM
it`s a 2pdt switch: 1p increases LFO output amplitude,
the other switches on audio FB.
So it sort of "flangerizes" the circuit:icon_question:
Quote from: puretube on December 29, 2005, 02:14:02 PM
it`s a 2pdt switch: 1p increases LFO output amplitude...
this part of the switch takes care of the LFO voltages
Quote from: puretube on December 29, 2005, 02:14:02 PM
...
the other switches on audio FB.
this part switches feedback of the phase-shifted signal in and out of the audio-circuit
The MXR Phase 100 has a 4-position switch that gets the 4 combinations of more/less resonance and wider/narrower sweep. The Small Stone "color" switch reduces this to 2 combinations. In one position it produces a narrower sweep range with less regeneration/feedback/resonance (pick your favourite word for it). In the other position it produces a wider sweep (generally sweeper a bit higher, rather than starting lower as was suggested), and introduces a bit more feedback/regeneration.
If you look at the Piedrita swchematic at Tonepad (a Small Stone clone that is identical but substitutes different OTA chips), you will see that after the last phase shift stage based around IC4, the phase-shifted signal follows two paths: one via a 27k resistor to the output mixing stage, and the other via a 3k3 resistor, 27k resistor, 0.1uf cap and either a 270k resistor or a straight wire path back to the input just after the 100k input resistor.
At the same time, the other set of contacts either shunts the 22k and 15k resistors, or places a 1k8 resistor in parallel with the 1k resistor. The circuit built around IC5 is the LFO.
If a person wanted to, it would be an easy and smart thing to split the two functions of the Color switch into two toggle SPDT switches: one for sweep width, and the other for regeneration.
Alternatively, you can substitute a 500k pot for the 270k feedback resistor. The Color switch either presents zero ohms or 270k along the feedback path. As the resistance goes down, the amount of feedback/regeneration is increased. Replacing the 270k fixed resistor with a 500k variable resistor will let you go from practically zero feedback to the maximum value for the Small Stone. If a little more feedback or playing with the edge of oscillation appeals to you, try reducing the 27k resistor before the 0.1uf cap in series with a 22k value or if you're daring an 18k part. You could also consider replacing the 4k7 resistor in the 3k3/4k7 network (which serves as a preset attenuator) with a 6k8 unit. Do not replace the 27k series resistor AND the 4k7 resistor to ground.
As for making the width variable, I'm afraid this is beyond my knowledge of OTA based oscillators.
> t`s a 2pdt switch: 1p increases LFO output amplitude,
.... which makes the sweep wider.
Your original question related to the LFO. As stm has detailed the other part of the color switch adds peaks to the audio through feedback.
Many phasers user feedback to add peaks (check out Ibanez units for example). I'm sure the Boss unit would do the same, it's a common trick.
One thing about the Small Stone is the feedback is done in a slightly different way: the clean signal path is "modified" by the freedback.
"Small Stone is the feedback is done in a slightly different way: the clean signal path is "modified" by the feedback"
Doesn't all feedback "modify the clean or dry signal? how does the small stone "modify" the clean signal different?
sweep width variable, I'm afraid this is beyond my knowledge of OTA based oscillators
Whats the different between a OTA Based oscillator VS a regular LFO oscillator?
the OTA based oscillator output Current?
the regular LFO oscillator output voltage?
How do we change the sweep width in most common LFO oscillators? it seems the swing voltage rails would make the LFO sweep width different because of the swing range?
>Doesn't all feedback "modify the clean or dry signal? how does the small stone "modify" the clean signal different?
The idealized model of a phaser is that one path is clean and second path is modified using an all-pass filter. The all-pass filter characteristics are modulated by the LFO, the clean path is unaffected. When feedback is used the feedback is applied to the all-pass filter, the clean path is again unaffected. The two paths are then mixed at the end. A phaser doesn't *have* to follow this structure there are actually other ways of achieving the same final result.
> Whats the different between a OTA Based oscillator VS a regular LFO oscillator?
The main difference/advantage is the OTA based LFO can easily produce a parabolic shaped LFO output - as opposed to the linear/triangle outputs produced by opamps etc. A parabolic LFO output sounds more natural and smoother. For the record you can get linear/triangle from an OTA. And with non-linear devices like diodes you can get parabolic outputs from an opamp (see the Mutron biphaser). The multiplying nature of the OTA provides a natural and predictable means of getting a parabolic sweep.
> the OTA based oscillator output Current?
> the regular LFO oscillator output voltage?
That's part of the internal behaviour. While most OTAs are based on current outputs somewhere deeper in the circuit, usually the current output is converted to a voltage output with buffer. So really you end-up with voltage outputs. That's not the important difference.
> How do we change the sweep width in most common LFO oscillators? it seems the swing voltage rails would make the LFO sweep width different because of the swing range?
Yes the voltage rails will change it but the voltage rails are limited, it's not the place to do it. A triangle output LFO swings at less that the supply range. The voltages that correspond to the peaks of the triangle output are set with a threshold in the circuit - more often than not a Schmitt-Trigger circuit is used. To increase the LFO swing you widen the two threshold points of the Schmitt-Trigger which makes the LFO output go higher/lower.
The side effect of *just*changing the thresholds is that the LFO speed will drop - that's because the rate the triangle ramp is increasing is fixed and now you have told it to go higher and it takes longer to to that. So, to compensate to have to modify the timing part of the circuit to speed it up, for example by decreasing the timing capacitor.
You probably need to study the two opamp Schmitt-Trigger/Integrator LFO circuit. There's plenty of these on the Web and you should be able to find some theory on it.
Thanks George Giblet alot for the information
LFO types:
#1.) two opamp Schmitt-Trigger/Integrator LFO circuit- mostly outputs a linear triangle waveform
#2.) Phase shift oscillator LFO(univibe)- mostly outputs a sine waveform
the phase shift network in the negative feedback in the oscillator section sets the range and width?
#3.) OTA oscillator LFO- outputs a parabolic shaped LFO output
Why do they use a parabolic shaped LFO for OTA's?
what does the parabolic shape differ from a sine wave phase shift oscillator?
The parabolic shape waveform would move/shift the notches/peaks up and down different than a sine wave (univibe) phase shift oscillator LFO?
Phase shifters move the notches/peaks up and down in frequency or ampitude?
a flanger moves the notches/peaks in Time not up and down but left to right "shifting" the notches/peaks
parabolic waveforms look like:
http://crca.ucsd.edu/~msp/techniques/latest/book-html/node176.html
> Why do they use a parabolic shaped LFO for OTA's?
As I mentioned before the parabolic sweep sounds more natural.
Take this idealized case to see why: When you have a linear sweep each say 0.1V of sweep corresponds to fixed change in notch frequency say 200Hz independent of where the LFO is at. When the LFO makes a 0.1V change and a notch is at low frequncies say 100Hz, a 200Hz change put the notch frequency at 300Hz; a 3 times the starting frequency. When the notch is a higher frequency say 1000Hz, a 0.1V LFO change moves the notches to 1200Hz; only 1.2 times the starting frequency. Your brain roughly interprets frequency changes on a log scale. Therefore the 0.1V change at 1000Hz is perceived as a small change compared to that at 100Hz, you would need to move the notche from 1000Hz to 3000Hz to get the same perceived changed as 100Hz to 300Hz.
The parabolic output is like a set of hills next to each other, similar to like a full-wave rectified sine-wave. In reality the hills are inverted. What the parabolic LFO does is stretch out the amount of time spend in the low frequencies, ie. the rounder part of the hill, and less time in the higher frequency part, ie the spikey joins in the hills.
> what does the parabolic shape differ from a sine wave phase shift oscillator?
The parabolic shape is asymmetrical ie. has a narrow spikey part and a wider round part. It spends more time with the notches at low frequency. The sine is smooth on the upper and lower part of the hills but it doesn't balance out the times spent at high and low frequencies. The sine-wave makes smooth sweeps compared to the triangle but it still suffers the problem surging sound because the notches get moved quicker at low frequencies. Mind you there's no "correct" LFO some people like the surging sound.
> The parabolic shape waveform would move/shift the notches/peaks up and down different than a sine wave (univibe) phase shift oscillator LFO?
Yes it's different, as explained in the first paragraph.
> Phase shifters move the notches/peaks up and down in frequency or ampitude?
Phaser change the frequency response over time. The thing which is changing is frequency based not amplitude. However, the frequency response is not flat, it has notches, and as the notches move you will hear some form of amplitude change if your signal is around the notch frequency.
>a flanger moves the notches/peaks in Time not up and down but left to right "shifting" the notches/peaks
The phaser does the same it moves the notches left/right on the frequency response as the LFO sweeps.
In terms of broard brush stokes there is a lot of similarity between Flangers and Phasers.
> http://crca.ucsd.edu/~msp/techniques/latest/book-html/node176.html
Yes!
Thanks George Giblet for the help,your time and information about this
What causes that LFO surging sound? Throbbing? breathing LFO sound?
"To increase the LFO swing you widen the two threshold points of the Schmitt-Trigger which makes the LFO output go higher/lower"
Notch depth- means the mixture of the dry signal with the time delay frequencys notched out. The more the notches the more the notch
depth. Mostly this is the summing/mixing stage or the FETS or LDR used can change the Notch depth
Notch Width- means the frequency's thats are notched out, this is set by the phase shift filter
LFO offset- changes the range of the swing of the LFO. So example of the LFO output is 5voits p/p with zero DC offset the range of the
swing is 2.5volts Peak sweeping the FET or LDR.
If we add Positive DC offset of 1volt then the sweep range changes the "Range Width" ? because the FET or LDR are going to have a different Swing/sweep range
If we add Positive DC offset of 1.5volts then the sweep range changes ?
If we add Negative DC offset of -1.5 volts then the sweep range changes ?
Manual Parameter- this replaces the LFO with a static delay time, the notches/peaks are not moving.
If we add Positive DC offset to the Manual parameter then the notches/peaks change because the Range has
changed. If we add Negative DC offset to the Manual parameter then notches peaks changes the range.
The DC offset shifts the notches/peaks range up or down
If the LFO "sweeps" the Notches up and down the DC offset "shifts" the notches up and down also but whats different?
they both move the notches up and down but how they do it is different
LFO outputs a 5 volt p/p its going to swing/sweep the FET resistance
When adding positive or negative DC offset how does the FET or lamp or LDR change from having DC offset?
Thanks for the help and knowledge
> What causes that LFO surging sound? Throbbing? breathing LFO sound?
The rapid changes of the notch frequency (and associated pitch shifting) at low frequencies.
> Notch depth- means the mixture of the dry signal with the time delay frequencys notched out.
Yes. The notch depth is simply how deep the notches go on the frequency response plot. You get deep notches when the "gain" of the all-pass filter bank is unity (=1) when the total phase shift is 180deg, 540deg etc.
> The more the notches the more the notch depth.
No. The number of notches is independent of the depth - different things. The number of notches is determined by the number of stages.
> Notch Width- means the frequency's thats are notched out, this is set by the phase shift filter
Yes.
> LFO offset- changes the range of the swing of the LFO.
The primary intention of the LFO is that it changes the *position* of the notches. In practice the range (or span) of the sweep is affected but that's not the main purpose (LFO offset is like the manual Knob on a flanger).
> Manual Parameter
> If the LFO "sweeps" the Notches up and down the DC offset "shifts" the notches up and down also but whats different?
There's two cases here. The first is where the LFO is completely removed and the all-pass circuits are controlled by a manual control - this is the case where the notches don't move over time. The second is a manual control which works with the LFO, this is basically an LFO offset which lets you move the notch positions but the sweep is still active. As an idealized example, one notch might cover 300Hz to 1000Hz. When the LFO is added the sweep will cover 600Hz to 2000Hz (double frequencies) for a logarithmic control but For the linear case the notch will instead cover 600Hz to 1300Hz (adding 300Hz).
> When adding positive or negative DC offset how does the FET or lamp or LDR change from having DC offset?
It behaves as descibed above. However, the amount of voltage offset you can add is limited by the device or circuit you are controlling. A JFET works over a very small control voltage range say -3V to 0V. Everything happens in that range. If you want to add offsets that will need to be small like 0.5V to 1V for example. A +5V to -5V offset just isn't going to work here. Each device has is own operating range, and each will require a *different offset voltage range* to achieve the *same result*.
Thanks George Giblet for correcting me and adding your information to the questions because i need the help
Does a phase shift *pitch shift* the notches? how does it pitch shift the notches?
Does a phase shift oscillator LFO pitch shifts the notches?
LFO is that it changes the *position* of the notches
What is this "positions" of the notches? what u mean by the "positions"
The DC offset changes the "positions" of the notches also but whats the main difference please?
The number of notches= by the number of stages
Notch depth means ?
Quote from: markphaser on December 30, 2005, 09:31:02 PM
The number of notches= by the number of stages
Number of notches = number of stages divided by two
Notch depth = how much the "notched" frequency is eliminated, you can measure it in dB, but I think on phasers the notch is supposed to be infinite (that is, the frequency totally disapears. That is, if the input has that frequency present, it will not be at the output).
This is very well explained at The technology of phasers an flangers at GEO http://www.geofex.com/Article_Folders/phasers/phase.html
You should read it, as it is very clear (that's where I learned the little I know ;) )
Miguel
Some questions have been covered.
> Does a phase shift *pitch shift* the notches? how does it pitch shift the notches?
Notches themselves don't cause pitch shift. The notch is caused by the all-pass signal cancelling out the dry signal at particular frequencies (the 180deg mentioned in previous post). If the notches are not moving in time, ie. there is no LFO and a fixed manual control/offset, there is no pitch shift.
The pitch shifting come about when the circuit behaviour is modified over time, in the case of an all-pass filter the phase shift produce by the filter changes over time. When the phase shift is varied over time you get a perceived pitch shift.
> Does a phase shift oscillator LFO pitch shifts the notches?
It is important to realize that it doesn't matter how an LFO works internally, all LFO which produce the same output will sound the same. A phase shift oscillator is just one method of producing a sinewave output. (Note: Most phase shift oscillators do not produce pure sine waves the output is slightly distorted.)
> The DC offset changes the "positions" of the notches also but whats the main difference please?
The LFO determines how fast the notches change in time and the*span* of frequencies the notches are moved over.
The DC offset determines the what frequency the notches move around. See above post:
"> Manual Parameter
> If the LFO "sweeps" the Notches up and down the DC offset "shifts" the notches up and down also but whats different?
There's two cases here. The first is where the LFO is complete...."
Thanks so much George Giblet for answering my questions
"Most phase shift oscillators do not produce pure sine waves the output is slightly distorted"
Like crossover distortion?
What does this distortion do to the notches does it vary them differently?
I thought a LFO varyed the notches only in amplitude up and down
Because if the LFO is outputing a Triangle waveform i thought it just used the triangle waveform to ramp up and down
the amplitude of the notches only.
How does a LFO vary the notches in Time?
How do u set the LFO to move the notches in Time?
Is there a way to set the LFO to move the notches more or less in time?
In phase shift Vibrato pedals the LFO moves the notches in time but how much in Time? is there a setting
inside the LFO circuit to vary the "LFO time" so the notches "Shift" in time differently?
Thanks alot George Giblet for all these
would changing the LFO "time period" change the notch shift? or moving the notches in time
For a phase shift vibrato pedal it shifts the notches the LFO "time period" is what sets the "Shift points"?
The LFO circuit does have a "time period" which shifts the notches left to right i think
the notches result from mixing the phase shifted and input
signals. If you remove the input signal from the mixing node to get the vibrato
effect there are no notches.
If there is no dry/clean signal mixed with the phase shift signal is there notches or no notches?
Because when i hear a vibrato pedal like a univibe on vibrato mode i hear the notches moving in and out of time/frequency
so the LFO is moving the notches back and forth?
When mixing the Dry+phase shifted notches= notches
When no dry at all just the phase shifted notches= notches
Whats the difference?
If there is no dry/clean signal mixed with the phase shift signal is there notches or no notches?
You answered your own question with the previous paragraph:
the notches result from mixing the phase shifted and input
signals. If you remove the input signal from the mixing node to get the vibrato
effect there are no notches.
Because when i hear a vibrato pedal like a univibe on vibrato mode i hear the notches moving in and out of time/frequency
so the LFO is moving the notches back and forth?
OK, so you've established that mixing dry with wet produces notches. It's been pointed out that the phase shifter shifts the phase of the input signal, depending on the frequency of the signal, etc. It's also been pointed out that this phase shifted signal, which is the wet signal, gives the effect of shifting the frequency up and down. The LFO's sole job is to shift the phase of this signal up and down and up and down. If the LFO stops, the phase shift freezes at that point. If the LFO starts again, it shifts the phase up and down and up and down.
The LFO output is a voltage that rises and falls. When the voltage rises and falls, the phase shift rises and falls. If the voltage stops at 2V, you have the amount of phase shift on the wet signal that the LFO provides at 2 volts. if the voltage stops at 3V, you have the amount of phase shift the LFO would provide at 3V. Look at it this way, you decide you don't want an LFO. You just put in a pot that you can adjust the voltage that determines how much phase shift is in the signal. You turn the pot to 1V, and get X amount of shift. You turn the pot to 2V, and get Y amount of shift. You get a wild idea and start turning the pot up and down and up and down. Your hand and the pot have now formed an LFO. That's the function of the LFO. It just puts out rising and falling voltage, it doesn't matter if it's a phase shift LFO, an integrator and schmitt trigger, or a photocell tracking how much light shines on it from the sun. All it wants to do is shift the phase of the wet signal.
Do not confuse the phase shift of the wet signal with notches. You said yourself that notches are only created when mixing dry and wet signal together. This is true. So, you only have notches when you mix the dry and wet signal together. When you do this, you hear the classic 'phase shifter' sound. 'Phase Shifter' is just an easy term for what it really is. To make it more clear, they could have called it "A Device That Takes Your Signal, Sends It Down Two Paths, Shifts the Phase of the Signal On One Path, And Mixes It Back With The Original Signal to Form Notches'. But, this was just too wordy, and most people don't care anyway - they just like the sound.
On your Univibe, they should have just called the switch 'The Control That Doesn't Let The Phase Shifted Signal Mix Back With The Original Signal, But Instead Only Puts Out The Phase Shifted Signal So It Has A Vibrato On It'. But, they ran out of room on the box, so they just gave it a short little name hoping no one would notice.
So:
When mixing the Dry+phase shifted notches= notches
Is correct. And
When no dry at all just the phase shifted notches= notches
Is incorrect. Because, when no dry at all means to me that you have not mixed the phase shifted signal with the dry signal. Your first paragraph already nulled this. It means nothing. Notches do not shift phase. A notch is created when a phase shifted signal is mixed with the dry signal.
Whats the difference?
Breadboard the simplest phase shifter you can find. Then you will know. Breadboard everything you've asked about, whether it be phase shifters or flangers or fuzz boxes or whatever. The knowledge you glean will help someone else. And, it's fun. Use your computer to go to Jameco, order parts and one of their good breadboards. Go to Aron's shop, go to Small Bear, go to Mouser, buy parts lots of parts parts to fill bins and bins and bins. Buy wire. Get a good power supply. Go grab schematics of all the things you want to try out, print them. Put them in a file. Sleep with them under your pillow, whatever it takes to motivate you to do something.
Then, turn your computer off.
I've read all of your posts on this board, and a lot other boards you frequent, as much as could I allot time for anyway. Friendly advice - you spend waaayyy too much time on the computer asking and not enough doing. The proof in that is the number of questions asked divided by the time frame the questions were posed. Turn off the computer, go outside. Breath air. Look at the clouds. Listen to the birds. And, above all, plot your next move, which is to build something that you can call your own.
Asking is good, but doing is good, too. Between the two, I'd say doing nudges out asking when all is said and done. When you have a problem, try to solve it on your own first. If you can't solve it, don't feel bad about it, turn your computer on and ask someone here. At least this time you'll be asking something more constructive and less theoretical. You'll find yourself doing that less and less and feeling better and better about yourself and even helping people. I'm not saying this to be a prick, I think you've got it in you to build a monster. You've just got to do it. Otherwise, why bother asking?
Cheerio,
Scott
Thanks DiyFreaque for the help
'The Control That Doesn't Let The Phase Shifted Signal Mix Back With The Original Signal, But Instead Only Puts Out The Phase Shifted Signal So It Has A Vibrato On It'
If the output if just the Wet signal and No dry signal being mix if it's not notches what are they ? because when i just hear the wet signal with out the dry being mixed i hear the vibrato is are they notches or ? what sorry i don't got the name for it so i called them notches but the phase filter produces a wet signal so the output is a vibrato so the LFO must be shifting something.
Yes i know the phase filter is changing the phase of the frequencys and the LFO is shifting up and down but with a vibrato wet signal the LFO seems to be shifting left to right instead of up and down
THanks for the help to clear me up on this
> Yes i know the phase filter is changing the phase of the frequencys and the LFO is shifting up and down but with a vibrato wet signal the LFO seems to be shifting left to right instead of up and down
With the vibrato (ie. Dry path removed) there are no notches at all. The frequency response of the all-pass filter chain is flat. What you hearing is entirely due to pitchshift. The pitch shifting arises because the phase (of the all-pass filters) is being modulate over time by the LFO.
Thanks George Giblet
The pitch shifting arises because the phase (of the all-pass filters) is being modulate over time by the LFO.
Can u please explain to me about how the LFO modulates over in time?
Does the LFO "time period" affect the pitch shifting?
How do i adjust the "time period" of a LFO?
What does the "time period" of a LFO do to the notches or controlling element?
Does the LFO "time period" change the LDR or Lamp or FET ?
How do i change the "Frequency" of the LFO?
what sets the Frequency of a LFO?
I need help with these questions can someone explain or give some feedback to me
http://www.elixant.com/~stompbox/smfforum/index.php?topic=40557.0
DiyFreaque can u help me with my questions ?
markphaser, there's a couple of things you need to get straight.
An LFO is just an oscillator, very roughly categorized as an oscillator with a frequency less than 15Hz or so. It is an oscillator in it's own right regardless of what it is connected to eg. part of phaser, LED flasher. As already mentioned, an LFO can produce different waveforms but that doesn't change the fact it is just an oscillator. In most cases different types of circuits are required for different waveforms. For any given waveform there is more than one type of circuit that will do the job.
The frequency of the LFO is a matter of choice when designing the oscillator, and to a large extent so is the range of frequency adjustment from the speed pot - some types of oscillators don't allow arbitrary adjustment ranges with a single gang pot.
> Does the LFO "time period" change the LDR or Lamp or FET ?
The second thing the realize is the LFO output is used to control something else. In a phase the thing that is controlled is the all-pass filter frequency characteristics. For example the frequency response of the all pass filter is tunable (adjustable) using a resistor and capacitor components which are part of the filter. The resistor is fixed. In a phase the resistor is replaced with an adjustable resistance. The adjustable resistance is an LDR or JFET. The LFO voltage controls the LDR or JFET, that changes the resistance which then changes the all-pass filter frequency response. So in effect as the LFO output voltage changes over time the all-pass filter behaviour changes with it - this type of thing is call a swept filter.
What you need to do is read up on oscillators, all-pass filters, and voltage controlled resistances (like a JFET). You have to undertsand each one of these in isolation fairly well before you can grasp the whole picture of how these all work togther to form the basic behaviour of a phaser - as a bonus you will be able understand other things like flangers, chorus, tremollo.
Quote from: George Giblet on January 06, 2006, 06:37:22 AM
What you need to do is read up on oscillators, all-pass filters, and voltage controlled resistances (like a JFET). You have to undertsand each one of these in isolation fairly well before you can grasp the whole picture of how these all work togther to form the basic behaviour of a phaser - as a bonus you will be able understand other things like flangers, chorus, tremollo.
Good luck. He doesn't like to read.
Markphaser,
I can't really add anything to what has already been laid out - the questions you've posed have been answered already in this thread (and others). I linked to the breadboard thread hoping you'd be inspired to get a known good working phase shifter schematic, breadboard it, get it working and let the lightbulb appear over your head once you probed around and also listened to it.
Good luck with your quest(s),
Scott
Thanks George Giblet
The speed/rate pot changes the oscillation Frequency?
How do i change the "time period" of the LFO? because the output of a LFO is like 40ms or 15us or 60us triangle,sine,squarewaveforms
im trying to adjust the "time period" of the LFO waveform how do i do this what part of
the LFO circuit does this?
I thought the speed/rate pot change the negative feedback frequency?
How do i change the oscillators frequency?
mp, this is an illustration of why I can't help you.
The time period of a cyclical wave is one divided by the frequency. One is the arithmetic inverse of the other.
You fail to grasp that frequency and time period are the inverse of one another, after being told so by multiple people, in different ways. You fail to grasp that the speed pot changes the frequency of the LFO, after being told so in multiple ways. You do not read the references presented to you by multiple people to help you. And that's just on Low Frequency Oscillators.
On top of that, you will not respond in any constructive way to requests for information about your background so that someone can inform you at a level you can understand. The fact that the time period of an oscillator is the arithmetic inverse of the frequency is one of the first things that one learns about AC waveforms. Therefore, you cannot have had that training to any significant degree, or cannot use the information if you did have it. This is only one of the things that make it obvious that you don't have much training in electronics.
It is incredibly inefficient and difficult for this group to train you in basic electronics by answering basic questions on an ad hoc basis as you think of them. Even if the group were willing to absorb themselves in providing individual tutoring for you, it would take essentially forever to respond to your questions and then go back on each question and teach you the background needed to understand any given answer. You cannot successfully get an airplane off the ground by finding out every few feet that you should have built more runway.
As I was sadly forced to note before, I cannot help you until and unless you will provide me with enough information to help you at the appropriate level. Your choosing not to do that seems to me to be a positive decision on your part not to participate in learning. And I cannot teach someone who says they want to learn, but only the bits and pieces that they are fondly eyeing at the instant, and not the foundations that would truly help them learn.
With regret, I have concluded that I cannot help you. I do hope that you are able to get some help someday.
I was bored and irked with this guy and did a search using some of his clues and found him on the following sites:
Gearslutz
walters
homerecording.com
walters
Join Date: 04-29-2005
"walters is infamous around these parts"
diyaudio
walters9515
Harmony Central
walters9515
DIYStompboxes
markphaser
Plexi Palace
Brentwalters
Recordingconsoles.net
brent
Guitar Geek
walters9515
3daudio inc.
walters
From his questions you can tell it is the same person. Some view him as performance art, some a nusance, I am thinking it is some grad student's attempt at AI and it is really just a software program we are all responding to.
Yes i know frequency and time period are the inverse of one another
speed pot changes the frequency of the LFO? yea but only in the oscillators frequency range im trying to change the oscillators frequency
range
Low Frequency Oscillators- What sets the oscillators frequency range?
The fact that the time period of an oscillator is the arithmetic inverse of the frequency is one of the first things that one learns about AC waveforms.
When making a LFO the LFO can be 40us, 60us,80us,40ms,60ms,80ms how do u set this?
The design of the oscillator has to have a FIXED frequency and then the speed pot changes the frequency of that range only
im trying to change the FIXED frequency and the time period of the output waveform
example if the LFO is 15hz or 20hz the speed pot can only vary so many frequencys i want to change the LFO to like 50hz how do i do this what sets the LFO "HZ" or frequency range
If the LFO is 15hz the time period of the LFOs output can change from 40us,60us,80us,40ms,60ms,80ms
the speed pot does change the time period of the LFO but its only a range of frequency/time period im trying to "change" the
time period into different "ranges"
Please excuse me gentlemen, but I knew I would find all of you here with your attentions fully engaged, hahaha!!! I'm not Walters, but could use some help on a Bad Stone debugging:
http://www.elixant.com/~stompbox/smfforum/index.php?topic=40457.0
examples:
The univibe LFO frequency and time period ? the frequency of the univibe LFO is? the time period range is?
The Bad stone LFO frequency and time period ? the frequency of the univibe LFO is? the time period range is?
MXR Phase 90 LFO frequency and time period ? the frequency of the univibe LFO is? the time period range is?
MXR phase 100 LFO frequency and time period ? the frequency of the univibe LFO is? the time period range is?
DOD phaser LFO frequency and time period ? the frequency of the univibe LFO is? the time period range is?
BOSS phaser LFO frequency and time period ? the frequency of the univibe LFO is? the time period range is?
The frequency range of the FIX oscillation of the LFO is a certain range
The time period can range from 10ms-900ms or 10us - 900us ranges
It's like shoveling sand against the tide.
Quote from: R.G. on January 06, 2006, 06:05:15 PM
It's like shoveling sand against the tide.
Pushing with a rope...
very good R.G
The univibe has a different time period output and oscillation frequency for the LFO
The speed/rate pot changes the time period or frequency of the oscillator but the range of the oscillation frequency is FIXED
so u can only get so many time periodes like 40us-100us or something its limited. By changes the LFO or oscillation frequencys
u can get more time periods this is what im talking about
Putting the probe down on the output of a LFO can see the sinewave or triangle wave and measure the time period and get the frequency but thats not the frequency of the frequency oscillations of the oscillator
I'm sorry markphaser. You've refused to provide any cooperation that would let me provide effective help. Best of luck to you in the future.
I just asked how do i get more "time periods" out of a LFO and how to change the LFO Fixed oscillation frequency?
whats so hard about telling this?
I'm sorry markphaser. You've refused to provide any cooperation that would let me provide effective help. Best of luck to you in the future.
Thats ok i didn't know i was doing anything wrong or refusing to provide any cooperation
I thought I was pretty clear what information I needed to be able to help you. Remember your posts over on Ampage? And my responses?
I'm sorry markphaser. You've refused to provide any cooperation that would let me provide effective help. Best of luck to you in the future.
i told u i don't have a electronic background with master degrees im just self taught whats the problem with knowing my electronic
background what does that have to do with anything. The question and answer will be the same my electronic background should have nothing to do with the answers to the questions so i don't know where u are going at with this. If i said i had a 4 yr electronic degree are you going to give me a 4yr degree answer to the question? or a 2yr degree answer to the questions?
wow, its walters! ;D
hello... you have legendary status in this forum. i've only read of you in the archives, and now you're back :icon_mrgreen:. i have nothing against you, and i wish i could answer some of your questions.
you are undeniably more knowledgeable than me, and i'm sure that if you spent a teensy bit more time helping others rather than asking your own questions, you would be more welcome here.
R.G. is pretty good at explaining things, try to accommodate him.
R.G. is pretty good at explaining things, try to accommodate him
Really he seems to want to know more about my electronic background then the questions i have posted
i wish someone would just explain and help out
markphaser, Have you tried to build anything ? If so what ? Some of the things you speak of might be easier to explain if you had a model to work with.
Andrew
Quote from: markphaser on January 06, 2006, 07:10:31 PM
R.G. is pretty good at explaining things, try to accommodate him
Really he seems to want to know more about my electronic background then the questions i have posted
i wish someone would just explain and help out
I know I'm going to regret this. But look, knowing your background dictates how to explain things properly. You can't just rapid fire questions and expect us to be able to just blindly explain. There are some things you have to understand FIRST before you can understand others. Like a house, you can't put the roof on until you've built the walls. You can't build walls until you've built the floor. You can't build the floor until you've put in a foundation. Electronics are the same way. You are asking questions whose answers don't make sense unless you understand other things. If you don't understand the answer, then more questions come, and eventually its more than someone can just sit down and explain all at once. This is what R.G. was saying. You give no indication that you understand the responses, or even WHAT you understand about the responses, so how can we tell how we are to explain your other questions? They are all related to each other. You have to give us info back if you want us to give it to you. Thats how this forum works. We wish you would just explain yourself so we CAN help you out.
Seriously, you've managed to irritate R.G., who is probably one of the most knowledgable and easy-going people here. To get on his nerves is a tough task. Just give back the info we need to help and we'll see what we can do.
EDIT: spelling corrections
sorry i asked about time periods and frequencys of a oscillator
Quotesorry i asked about time periods and frequencys of a oscillator
Please don't whine. No one is beating you, verbally or otherwise.
Quotei wish someone would just explain and help out
I don't see anything except people trying to explain and help out. I'd genuinely like to help you. I enjoy being able to point people in the right direction when they can profit from it. However, none of your responses to my replies or those of other people seem to have helped you much.
QuoteIf i said i had a 4 yr electronic degree are you going to give me a 4yr degree answer to the question?
Well, actually yes, if I thought what you told me was true. If I believed that you had a BSEE, I could tell you answers at that level, and if you were a high school student who'd read one book on beginning electronics, I could give you answers at that level as well. Those answers are fundamentally different.
What I can't and won't do is to blindly answer questions where the only indications I get back is that you didn't get helped by it in any way. It's not only no fun for me, it is useless or worse to you, as I'll explain.
Degrees are not necessary, and some of the best electronics techs I ever saw were self taught. They did however dig in like crazy when anyone pointed them to references, and they saved person-to-person questions for when they were truly stuck. They also took an answer that they needed to study and understand X before their questions about Y would make sense seriously and went and learned about X before revisiting Y.
What follows is just an illustration, and I hope you can take it for the helpful advice it's intended to be. I will discount the possibility that you don't understand English well. Not knowing the language here is a big handicap. I would be just as handicapped learning advanced biology in a Finnish university. But you have assured me that you're fluent in English, so fine, I'll take that.
The illustration: you don't understand oscillators. Not any flavor. You've been told the basics in several replies. An oscillator requires some source of gain, a feedback path, and the arrangement of that gain and feedback path to allow the gain to provide it's own input. That can be by components in the feedback path that shift the phase of the feedback to be correct to reinforce the input, or it can be by simply having the gain and feedback path have no phase shift at all (both noninverting and non phase shifting). Unless you not only understand those sentences but also have some background in what they mean, you're forever going to be lost in wondering how oscillators work, what controls the speed of oscillation, how to modify them, and so on. And no amount of detailed answer about how to tweak some fine point of one oscillator will ever help you understand how to make another kind of oscillator work because you have no principles to build the understanding on. I can't tell from your posts whether you understand what "phase" is either. Or feedback. Or time constants. Again, this is not criticism. I simply can't tell what level to tell you things so you don't immediately have to ask what I meant.
I realize that I'm insisting on trying to give you the understanding you need, not the answers you want.
But It's not useful to either of us to give you answers before you're prepared to understand them. It's worse than useless. At best it wastes your time, and at worst it confuses and delays any real understanding. So the questions about background were an attempt to find some firm basis that you have to tell you an answer you can understand, not just confuse the point, or worse yet, let you think you now understand something when there's a yawning gulf of things that are hidden from you by the one answer you do have.
So -
I'm sorry markphaser. You've refused to provide any cooperation that would let me provide effective help. Best of luck to you in the future.
An oscillator requires some source of gain, a feedback path, and the arrangement of that gain and feedback path to allow the gain to provide it's own input. That can be by components in the feedback path that shift the phase of the feedback to be correct to reinforce the input, or it can be by simply having the gain and feedback path have no phase shift at all (both noninverting and non phase shifting). how oscillators work, what controls the speed of oscillation, how to modify them, and so on.
Yes i know that oscillators need a gain and feedback path to make it oscillate. I'm talking about the "oscillation frequency" which sets the oscillators or LFO range. The speed/rate pot controls the frequency or speed of oscillation in the feedback path mostly in the negative feedback path or the phase shift network in the feedback path which changes the phase which will change the oscillation frequency.
Most LFO low frequency oscillators are around like 10hz to 20hz how can i convert a LFO to like 50hz or 80hz or 100hz the speed/rate doesn't do this so how do i modify a LFO to changes its "fixed oscillation frequency"?
Most LFO's have a "frequency range" and its limited thats why they call it a LOW frequency oscillation how do u make it a High frequency oscillator or just change the frequency range of the oscillation?
Phase shift oscillator LFO like the (univibe): what is the frequency range? 10hz? 15hz? 20hz? 25hz? 30hz? 35hz?
Comparitor/trigger LFO like most common phaser pedals: what is the frequency range? 10hz? 15hz? 20hz? 25hz? 30hz? 35hz?
The speed/rate pot doesn't change the oscillation frequency range it can't make a LFO low frequency oscillator into a high frequency oscillator is just changes the range which is limited
If the LFO is set at 15hz then the speed/rate pot can only go down to 10hz or up to 20hz maybe
If the LFO is set at 20hz then the speed/rate pot can only go below to 15hz or up to 25hz maybe
if the LFO is set a 10hz then the seeed/rate pot can only go below to 7hz or up to 12hz
See how the time constant of the LFO and sets the limited time periods/frequencys of the LFO?
This should help with your questions:
http://www.linuxbench.org/Posting.html
i know R.G knows about this stuff and can easily give the answers
Quote from: Fret Wire on January 06, 2006, 09:11:49 PM
This should help with your questions:
http://www.linuxbench.org/Posting.html
That was the funniest thing I've seen today. Thanks, FW. :icon_biggrin:
On the Harmony Central boards, I asked him to answer four questions in an attempt to get a feeling for his level of understanding. Here are the questions and his answers:
1. You have a 5 volt input, you want 3 volts out, you have a 33k resistor, what other resistor do you need (standard value 5%) to easily get the desired output voltage.
2. What is beta when used with bipolar transistors. What is the use of this, what is another name for this term, and why is it bad to rely on its value.
3. What is the difference between a sine and triangle and sawtooth oscillator. What are uses for each, and which is worst to use with a tremolo.
4. You have an op-amp. Your circuit is as follows, 1k to signal in on the + input, 1k to ground on the - input, and 10k from the negative input to the output. What is the gain. If you put the signal on the 1k on the - input and had the + input connected to ground what is the gain.
And His Reply:
Dude get off your horse
1. You have a 5 volt input, you want 3 volts out, you have a 33k resistor, what other resistor do you need (standard value 5%) to easily get the desired output voltage.
Its called a voltage divider
Use a variable resistor and put your DMM until its 3 volts output
and 5 volts for the input
2. What is beta when used with bipolar transistors. What is the use of this, what is another name for this term, and why is it bad to rely on its value.
Gain or alpha
U have to measure the gain/beta with a beta transistor meter
to match them
The use for gain is to get different distortion operations or to take a small signal like in the mV to boost to Volts
You have to bias it right for it to operate or it will be asymmetical output
3. What is the difference between a sine and triangle and sawtooth oscillator. What are uses for each, and which is worst to use with a tremolo.
They are different waveforms with different harmonics and overtones
The worst is Square wave
4. You have an op-amp. Your circuit is as follows, 1k to signal in on the + input, 1k to ground on the - input, and 10k from the negative input to the output. What is the gain. If you put the signal on the 1k on the - input and had the + input connected to ground what is the gain.
why don't u use a AC volt meter instead of making me into a human calculator
Just measure the Gain with a AC volt meter
Seems like your a Tech that is bitter about your past or your mentor or rolemodel was negative on teaching u electronics or your one of those techs that has learned the hard way and wants to rub off your negative additude onto others
To tell u the truth i really don't need your help there is other people besides you that are nicer and it willing to take some time and teach
Sir HC are u trying to hijack my thread again
Quotei know R.G knows about this stuff and can easily give the answers
Yes, I do. The problem that I was referring to is that your posting pattern seems to be that you can't understand the answers. That's why I was trying to find out what your background is so I can give you an answer at a level that you can understand.
A coule of illustrations:
Quote>>1. You have a 5 volt input, you want 3 volts out, you have a 33k resistor, what other resistor do you need (standard value 5%) to easily get the desired output voltage.
>Its called a voltage divider Use a variable resistor and put your DMM until its 3 volts output and 5 volts for the input
It is indeed called a voltage divider. However, your answer indicates that you don't understand voltage dividers. He gave you a trivially easy voltage divider question. If you really knew how voltage dividers work, you'd have either solved it in your head or written a couple of algebraic equations and came up with 22K immediately, no resistors, power source, or meter needed. The question was not a test of whether you could use a meter, it was a test of do you know what resistors do.
Quote
>>2. What is beta when used with bipolar transistors. What is the use of this, what is another name for this term, and why is it bad to rely on its value.
>Gain or alpha
>U have to measure the gain/beta with a beta transistor meter to match them
>The use for gain is to get different distortion operations or to take a small signal like in the mV to boost to Volts
>You have to bias it right for it to operate or it will be asymmetical output
Good guesses, but those are what you read in the forums, not what transistors actually do. Beta is gain, but it's the current gain. Alpha is the inverse of current gain. The use for gain is... well, gain. That is, the second of your answers. It's only a very tiny section of the audio community that even thinks of gain as about creating distortion. And while all devices need to be biased correctly to avoid creating distortion, that has little to do with gain. It seems that you have learned the forum buzzwords, and little else. That could well lead you to have a distorted view of electronics in general, and prevent you from ever getting a more complete understanding unless you get more basic help.
Quote
>>3. What is the difference between a sine and triangle and sawtooth oscillator. What are uses for each, and which is worst to use with a tremolo.
>They are different waveforms with different harmonics and overtones
>The worst is Square wave
They are indeed different waveforms, however, the harmonics and overtones they have are immaterial in this context. What is importat in a tremolo is that the waveform is being used to create an audible loudness proportional to the waveform, so the relative harmonics of each don't really matter. What matters is what they do to the loudness. There really is not a worse one. It all depends on what you want the sound variance to be. And many people actually like the on/off/on sound of a square wave tremolo.
Quote
>>4. You have an op-amp. Your circuit is as follows, 1k to signal in on the + input, 1k to ground on the - input, and 10k from the negative input to the output. What is the gain. If you put the signal on the 1k on the - input and had the + input connected to ground what is the gain.
>why don't u use a AC volt meter instead of making me into a human calculator
>Just measure the Gain with a AC volt meter
Once again, the question was not really "what's the gain?" It was really "do you understand opamp gain and feedback circuit basics?"
The gain of any opamp circuit with resistor elements is Rf/Ri when the signal goes into the inverting input resistor. It's 1+Rf/R1 if the signal goes into the noninverting input, so the answers are 11 and 10 depending on which input is chosen for input. No opamps, meters, or parts are needed. I's purely a mental exercise that really asks "do you understand the fundamentals of opamps?".
The bottom line is that you appear not to have an understanding of the fundamentals that would let you understand the fine points you're asking about. And that's my point about needing to know your background. Not having an adequate electronics background is not something to hide. We **all** started with zero knowledge about electornics. But if you don't build a good base to learn from, you may never get to a good understanding. And that's my point, belabored again.
the switch has two throws
what are the names of the positions?
they are not labelled
is it on and off?
or red and green?
which is which
What is the air-speed velocity of an unladen swallow ?
Here's one that's caused me a few sleepless nights in the past:
"Why is a carrot more orange than an orange?"
Madison Square Garden isn't on Madison, isn't square, and it isn't a garden. Discuss.
ok back to my thread and not hijacking it
An oscillator requires some source of gain, a feedback path, and the arrangement of that gain and feedback path to allow the gain to provide it's own input. That can be by components in the feedback path that shift the phase of the feedback to be correct to reinforce the input, or it can be by simply having the gain and feedback path have no phase shift at all (both noninverting and non phase shifting). how oscillators work, what controls the speed of oscillation, how to modify them, and so on.
Yes i know that oscillators need a gain and feedback path to make it oscillate. I'm talking about the "oscillation frequency" which sets the oscillators or LFO range. The speed/rate pot controls the frequency or speed of oscillation in the feedback path mostly in the negative feedback path or the phase shift network in the feedback path which changes the phase which will change the oscillation frequency.
Most LFO low frequency oscillators are around like 10hz to 20hz how can i convert a LFO to like 50hz or 80hz or 100hz the speed/rate doesn't do this so how do i modify a LFO to changes its "fixed oscillation frequency"?
Most LFO's have a "frequency range" and its limited thats why they call it a LOW frequency oscillation how do u make it a High frequency oscillator or just change the frequency range of the oscillation?
Phase shift oscillator LFO like the (univibe): what is the frequency range? 10hz? 15hz? 20hz? 25hz? 30hz? 35hz?
Comparitor/trigger LFO like most common phaser pedals: what is the frequency range? 10hz? 15hz? 20hz? 25hz? 30hz? 35hz?
The speed/rate pot doesn't change the oscillation frequency range it can't make a LFO low frequency oscillator into a high frequency oscillator is just changes the range which is limited
If the LFO is set at 15hz then the speed/rate pot can only go down to 10hz or up to 20hz maybe
If the LFO is set at 20hz then the speed/rate pot can only go below to 15hz or up to 25hz maybe
if the LFO is set a 10hz then the seeed/rate pot can only go below to 7hz or up to 12hz
See how the time constant of the LFO and sets the limited time periods/frequencys of the LFO?
I'm truly sorry, markphaser. I cannot determine any appropriate answer without knowing what fundamentals you do and don't know. I really wish I could help you. Best of luck in your future endeavors.
Quote from: bellyflop on January 07, 2006, 10:12:24 PM
What is the air-speed velocity of an unladen swallow ?
Crap, I used to know this one. What kind of swallow was it? Oh and my proudest moment skiing was when I crashed into a small bush and screamed out "Look, a shrubbery!"
It sounds like i can't answer your questions right or im not good enough. You already know my electronic background by Sir HC questions
and u said if u knew my electronic background u would give answers to the questiions so stop playing this game with Sir HC because
this is my point is that the questions that i ask are not just going to be "me" reading them so who cares what electronic background i have because other readers are going to read them also coming from all different levels of electronic educations or being self taught so if u want to help just answer the questions if u feel that my electronic background is not go for u or Sir HC to answer really simple questions for u then sorry i wasn't as gifted as u two and had the educations and schooling. So since u know my electronic background what happen to making the answer so easy for me to understand? or is this your and Sir HC games your playing?
Does my questions sound like i don't know my fundamentals of electronics? and if i don't know my fundamentals of electronics then answer the questions with answer that can be for someone that doesn't have fundamentals of electronics why are u making this so hard?
Dude, look, either you are joking and harrassing everyone, or you are unwilling to do the basic background work to understand what people are trying to tell you. Either way, you are not worth our time and effort. I can not teach you quantum mechanics if you don't understand classical physics, same with this stuff, you don't care to understand a voltage divider, I can not explain LFOs and the rest. Seriously, if you are for real, RTFM!!!!!!
Your harassing me with your questions
Did i ask about quantum mechanics or classical physics?
Do i know basic electronics ? yea i do
Do i have to prove i know basic electronics to you? no i don't
Do u have to answer my questions? No u don't i didn't ask u directly
Am i a joke? No but i know me and you don't get along
You wish i didn't know what a voltage divider does i learn that in the first day in my electronics class. DO i have to prove this to you no i don't because i asked questions
Either way, you are not worth our time and effort? good Sir HC please go away
Does Markphaser go in your threads asking u questions about your electronic background about op-amps,transitors,power supplys,filter caps,grounding problems,voltage dividers and when u answer them i say your not answering good enough? why would i want to ask with my educated answer for u Sir HC?
**"Don't try to make my thread into a Electronic Background Drama"** ok we are real men
Quote from: TELEFUNKON on January 07, 2006, 02:15:16 PM
the switch has two throws
what are the names of the positions?
they are not labelled
is it on and off?
or red and green?
which is which
above question was meant seriously, folks!
not intended to make fun of the topicstarter!
on my vintage box there`s up or down position,
but not labelled or named.
no schematic I`ve seen indicates up or down or on or off.