The systech phase shifter schematic has 2 trimmers a feedback rheostat trimmer and a "even/odd cycling trimmer"
Do u guys know what this "even/odd cycling trimmer" does to the LFO or FETs to the phase filters section?
It unsolders one JFET on the odd cycles, and puts it back in on the even cycles.
The trimmers make the JFETs bigger or smaller as you turn the knobs.
:)
Quote from: R.G. on November 09, 2006, 10:55:14 PM
It unsolders one JFET on the odd cycles, and puts it back in on the even cycles.
Hence the need for the rheostat.
QuoteHence the need for the rheostat.
Correct. That adjusts power factor and prevents overheating.
R.G i don't know if me and u are looking at the same schematic or even talking about the same schematic
please don't change the subject so other people that wish to contribute are not confused
Where is this schematic (I hate that word!!!)
QuoteR.G i don't know if me and u are looking at the same schematic or even talking about the same schematic
I'm pretty sure we are. To which schematic were you referring? Isn't this the one with the flux capacitor in the lower left hand corner?
As it's Friday I shall gripe - in the UK we call them circuit diagrams - is this yet another example of USAianism that we are stick with??? :icon_twisted: :icon_twisted:
QuoteAs it's Friday I shall gripe - in the UK we call them circuit diagrams - is this yet another example of USAianism that we are stick with???
Sadly, yes, its a bit of Am-english (as we xeophobically call it on this side of the pond) that we are *all* stick with. :icon_biggrin:
You see, the thing is that we USA'uns only got second choice on all the good words. You guys got "bonnet" and we have to use "hood". You got "windscreen" and we have to make do with "windshield". You get petrol when you fill up your cars, we have to get gas. When we're in a hotel, we have to be asked for a "wake-up call". You guys get to ask to be "knocked up".
As you can see, it's plenty enough to give us derivative-English users an inferiority complex. :)
So we make out where we can. If it's any consolation, it started out as "schematic circuit diagram" and because we're always in a rush, we shortened it down to "schematic diagram" then finally to "schematic", the "circuit diagram" being implied. No time to say all those extra words.
Oops! Look at the time! I gotta go - time's a-wastin'.
;D
Stephen, I dig your comment about Fridays... Still 6 more hours at work until I can go home to play with my new BB&E.
R.G., where do you source your flux capacitors? The clerk at Rat Shack told me they didn't carry them anymore due to the enforcement of the new RoHS policies--too much CdS (cadmium sulphide) inside. Nevertheless, this guy told me that I could replace the flux cap with a non-polar 10uF cap (after all they are both capacitors!), however I am a bit reluctant about this, since the flux capacitor I need to replace is labeled as 10MF / 1GV. The clerk says that the difference between the "u" or micro and "M" prefixes is not relevant as they both represent the letter "m", and the fact that the former is in the greek alphabet is irrelevant.
What should I do?
---------------------
P.D. I almost forgot, regarding the original question, I suggest doing the following:
a. Posting a link to the electrical *drawing* or *sketch* of the phaser to see what's this ODD/EVEN thing is about in that particular circuit..
b. Take a look at John Hollis' Ultra Flanger, drawing/sketch here: http://www.hollis.co.uk/john/ultraflanger3.jpg
As you will see on the upper-left corner, the ODD/EVEN thing has to do with applying feedback in-phase or out-of-phase (wet signal with direct or inverted polarity). The trimpots there are to establish the maximum possible feedback in each case without entering into self oscillation.
RG, what you say is interesting! In the nineteenth century, ladies wore "bonnets" on their heads, and we sometimes use the expression "look under the bonnet" to mean investigate something in detail - I'm an accountant so it crops up from time to time, and there's another - "crops up" who knows where that came from, crops being things that grow, usually on a farm which you probably call a ranch and our friends in Argentina call an estancia! Probably a connection there somewhere. And then there was a sailor called Chris Bonnet.............
"Bonnet" is still rural USA usage for a woman's headgear, usually only a homespun, simple thing. Much of USA rural usage came direction from poor Scots immigrants who settled in the USA Appalachain mountains and still use terms which are directly derived from the Scots' use of English. How's that for confusing? In any case, My mother possessed and wore bonnets, which were different from hats.
As much as it's tempting to think that "bonnet" was originally another term for "skirt", I think the term "have a look under the bonnet" comes from early 20th century usage on automobiles needing a lot of repair work after the covering over the engine was already called a bonnet. British (as opposed to "English") autos are famous here for needing mechanical work. The conventional wisdom is that you need a live-in mechanic if you own a British car, but I'm sure that is no longer true since the dual side-draft carburetor is no longer used.
We did once use "boot" for the rear luggage compartment in a car, but it's been "trunk" for as long as I've been alive.
Hmmm...
There once was a sailor named Bonnet,
Who penned a slacious faux-sonnet.
The subject, a lady,
An reputedly shady,
(You fill in the blanks here) on it.
Quotewhere do you source your flux capacitors?
The clerk is correct. You can insert almost any 10uF cap in the place of a genuine flux capacitor and get exactly the same operation as the original.
Just don't get into the "fanny pack" debate. :icon_mrgreen:
anyone have a charge pump circuit for 1.21 JigaWatts?
Quote from: markphaser on November 09, 2006, 10:50:04 PM
The systech phase shifter schematic has 2 trimmers a feedback rheostat trimmer and a "even/odd cycling trimmer"
Do u guys know what this "even/odd cycling trimmer" does to the LFO or FETs to the phase filters section?
I understand the temptation to be silly and frivolous guys, but lets be serious for a moment.
To respond to the questions....
The feedback rheostat trimmer does nothing to the FETs or LFO. If there is too much feedback, a circuit will break into oscillation. So, many circuits using feedback will include a trimmer rheostat to set the maximum feedback possible
without oscillation. This is true of many phasers, flangers, and analog delay lines. This is set by turning the feedback or regeneration or resonance control (whatever it is called on that pedal) to maximum, and setting the trimpot to the lowest resistance. This will produce oscillation, or what some call "runaway feedback". The trimpot is then gradually increased in resistance until the oscillation stops.
I do not know the Systech circuit, but what I will say is that the exact same amount of negative or positive feedback from the last stage will produce outputs of different volume levels, because one will produce notches and the other will add peaks. I am guessing here that the even-odd cycling trim might be something that adjusts the relative levels of negative-vs-positive feedback output levels to get something approximately equal level. Keep in mind that is just a guess and not based on a schematic or a detailed picture of the pedal.
Thanks Mark Hammer for being serious
I understand the feedback trimmer
The phase filters have FETS or LDR's and sometimes u see a trimmer thats inbetween the LFO output and the FET's or LDR's
but the trimmer is connected to the FET so make it unbalanced or balanced it changes the cyclicing from being even cycles to
odd cycles
even cycles: i mean u hear the swirl evenly everytime 1,2,3,4 swirl,swirl,swirl,swirl
odd cycles: i mean u hear the swirl 1,nothing,3,nothing swirl,nothing,swirl,nothing
DOD Phasor 201 schematic has a trimmer connected to the FET
MXR phase 90 and 180 has a trimmer connected to the FET to change the bias of it ?
EH bad stone has 2 trimmers after the LFO outputs inbetween connected to the FETS
it changes the cyclicing swirl interfacing the LFO to the FET biasing or something
They call it a Bias trimmer on some schematics. The bias trimmer is connected to the Gate and source of the FET in the phase filters
Could someone post a link to the schematic / circuit diagram for the Systech phaser?
Sorry Toneman i don't have the schematic in a PDF file or converted from a scanner
Whats the difference between a JFET,Mosfet,FET-based phasers?
Quote from: markphaser on November 10, 2006, 04:49:22 PM
Whats the difference between a JFET,Mosfet,FET-based phasers?
That's a VERY big question markphaser. You need to look through the archives. I'm certain there is discussion about it there that doesn't need to be typed all over again.
The even/odd cycles description you give is interesting and very unusual. Although it may exist, I have never heard of such a thing or heard it in action.
I forgot the name of what u call it but i have read about the trimmers that set the FET's in the phase filter stages
i remember u called them "soft or hard" reaction or something.
But yes i did turn the trim pot inside the system phase shifter and it did do the even or odd cyclicing
Even cyclicing: throb,throb,throb,throb
odd cyclicing: throb,fading out,throb,fading out
I know u mention about the Soft and hard FET biasing or something i don't know if this is the same but there is trimmers
between the output of the LFO and FETS that either bias the FETS to react difference soft or hard turning off and on or
the slew rates or change the "taper" of the FET resistance
mark,
the even/odd thingie has to do with the *number* of (jfet) stages.
Not, the "cycles".
The "bias trimmer" U keep referring to, is usually used to *bais* the jfet to the right "area",
so that, when the jfet "acts" like a variable resistor in the phaseshift stage, it does so smoothly and in a linear fashon.
SURE wish someone would post a link to the schemo (?)
But, it *sounds* like it's just a garden variety jfet phaser.
How many stages?? I don't know.
For a **really** unusual phaser, look at the SynthiHiFli phaser !!!
T
even/odd thingie has to do with the *number* of (jfet) stages.
Thats a even/odd notches
4 stages= even notches
6 stages= even notches
8 stages= even notches
10 stages= even notches
12 stages= even nothes
Where do u get a odd number of stages ?
JFET produce harmonic distortion is superimposes onto the AC wavefrom throught phase shift network thats why u get more
even harmonics
The "bias trimmer": the jfet "acts" like a variable resistor in the phaseshift stage it does so smoothly and in a linear fashon
yes i understand that
EMS SynthiHiFli phaser? i never seen the schematic for that but i think its close to the Mu-tron Bi phase
unless its a Odd stage phaser?
Quote from: markphaser on November 10, 2006, 05:19:21 PM
4 stages= even notches
6 stages= even notches
8 stages= even notches
10 stages= even notches
12 stages= even nothes
Where do u get a odd number of stages ?
It's where the *feedback* is tapped from,
Not the actual number of stages.
Quote from: markphaser on November 10, 2006, 05:19:21 PM
EMS SynthiHiFli phaser? i never seen the schematic for that but i think its close to the Mu-tron Bi phase
unless its a Odd stage phaser?
Not even close to the same......
::)
EMS SynthiHiFli phaser is in the HiFli combo its not a stand alone single phaser box right?
Quote from: markphaser on November 10, 2006, 08:13:37 PM
EMS SynthiHiFli phaser is in the HiFli combo its not a stand alone single phaser box right?
right. the phaser is in a big box with a bunch of other effects.
and.... it should be "EML".... Electronic Music Laboratories.
Don't know what happened to the edit function(?)
There used to be a little "edit" button on the page(?)....
Now, i don't see any...(?)
T
Toneman whats so special about his EML phase shifter circuit? the LFO ? the FETS? the LDR?s or phase stages ? and why?
Quote from: markphaser on November 11, 2006, 10:51:13 PM
Toneman whats so special about his EML phase shifter circuit? the LFO ? the FETS? the LDR?s or phase stages ? and why?
remember prevously, how U were asking about the number of stages??
answered
remember how U were asking about what constitutes odd/even phasing??
answered
the "uniqueness" of the EML is in **how** the feedback from the stages is done.
(but, i guess that's true of all phasers(?)
now, that that's answered.........
For further questions on the dark side of the phases,
U need to do as john fogerty said: Keep on Googlin'
t t t t t that's all from me......................................................
excuse me while I automatically shift phaserlylike outa here ............. warp nine, Mr Sulu .......
(wooshing sounds)
:)
T
Yes the same guy made the small stone and microsythn David %^&*ell
Yes the feedback can be tapped at any stage like the mxr phase 180 and small stone to get odd feedback
What happens when u tap off at different odd stages vs even stages from phase shift for feedback parameters?
?
Bode "played" with cyclic phase-inversions...
(
Quote...periodic sequence of inversion and noninversion...
)
What is cyclic phase-inversions mean please?
Quote from: markphaser on November 19, 2006, 02:25:16 PM
What is cyclic phase-inversions mean please?
Quoteeven cycles: i mean u hear the swirl evenly everytime 1,2,3,4 swirl,swirl,swirl,swirl
odd cycles: i mean u hear the swirl 1,nothing,3,nothing swirl,nothing,swirl,nothing
with the exception of 1 & 3 in above mentioned "even cycles"...
(so: not
everytime, but every
even time).
IIRC the EML phaser uses a diode ladder, as opposed to FETs, OTAs, or Vactrols.
What is cyclic phase-inversions mean please? do u mean its a LFO with a polarity or phase reverse?
the EML phaser uses a diode ladder, as opposed to FETs, OTAs, or Vactrols.
What kind of diode ladder configuration please?
(I'm looking in my electronic books about diode ladders and i don't see anything about them at all)
Whats the difference between a diode ladder,JFET,Mosfet,FET-based,OTA,Vactrol phasers?
diode ladders are mentioned here--
http://www.zephyrtechnology.com/UFO_Technology/Build_Flying_Saucer_/body_build_flying_saucer_.html
all U have to do is google!!!!!! ;D
instead, U ask 4 more Q's for every one that's answered :icon_rolleyes:
T
is that link for real?
http://www.zephyrtechnology.com/UFO_Technology/Build_Flying_Saucer_/body_build_flying_saucer_.html
markphaser, is that you in the photo (wearing a tie)?
btw, I think the even/odd trimmer is used for zeroing the polarity of the neutron flux. Some of the Zvex pedals, and older Wiard modular gear, use that trick.
very funny
Quote from: toneman on November 11, 2006, 10:26:16 AM
Quote from: markphaser on November 10, 2006, 08:13:37 PM
EMS SynthiHiFli phaser is in the HiFli combo its not a stand alone single phaser box right?
right. the phaser is in a big box with a bunch of other effects.
and.... it should be "EML".... Electronic Music Laboratories.
err,
studio, or
labs ?
http://www.sequencer.de/pix/ems/ems_hifly.jpg
(sorry - my eyes...)
I do like the HI-FLI the phase shifter does sound very watery
Whats the difference between a diode ladder,JFET,Mosfet,FET-based,OTA,Vactrol phasers?
A diode ladder phaser uses a diode ladder to do the filtering the other sorts don't. Google for diode ladder for more info, they're used in lots of synth filters.
so the diode ladder replaces the RC network no cap and no resistors its just diodes right in the filter part?
OK, PT, I ****really**** meant EMS..... sorry for correcting myself :icon_redface: :P
Did not mean to "confuse" anyone :-\
2 phase or 2 phlange...... it's all a Hoax!!!
May all your Harmonix be Electro and all your boxes be fuzzy 8)
oops!!! dang, i kept this thread going ..... :icon_rolleyes:
Oh..Kayyee..., **another** Answer for mark...
The Answer is: NO, not **just** diodes for a filter.
U ***really*** need to **really** google for "diode ladder" :icon_exclaim:
U will *actually* find *other* links (to filters), besides the ONE link i posted, which would have answered THIS Q more fully.
Anyway...................
now,.... i'm ***really*** phasing outa here.......(wooshing sounds)... :icon_cool: