polyphase gut shots....

[Scruffie]

My next question are the mixing resistors...

From one of those 1uFs there should be 2 x 3.6k resistors connected according to the schematic where as Paul used the values from an alternate schematic at 27k each which I think is why some people experienced weaker phasing compared to original units.

Now... seems 820k is the value coming off the Env Mod Pot middle lug which is listed as 620k on some schems (seem to recall people saying reducing this helped with the envelope sensitivity though...) and the resistor between pins 1 & 6 of the 324 is 100k not 39k like the above schematic which makes the 3/26/79 schematic I have the most correct one, not the one I posted above.

Under the rate pot though... connected to one of the lugs, the 2 x 10uFs and pin 3 of the 3140, that resistor... supposedly on the schematic an 18k, looks like 180k?

And up by the Env Mod, next to the 4558 (second one along) looks like 180k too? Along with the resistor lying sideways above the Vactrol at the closest end of the board below an opamp... or are they 18ks?

This is now what I think is the most correct schematic for this...
http://www.tasteundtechnik.de/bilder/polyphaseschem.jpg

See the greenie cap next to that big metal can too? What's the resistor value next to that, that should be a mixing resistor if i've traced it right (which I might not have).

Oh and this is the cap you put a 1uF in place of a 10uF, the one next to the 220uF and empty pads-

[pinkjimiphoton]

just checked again, my mistake...  .47, not .047 bro.

5 smaller transistors, 1 large one.

big one is marked 2n6290

small ones are 2n5088 next to the 4013bpc

2 2n5087's

1 2n3904

[pinkjimiphoton]

scruffie,
i will get to this asap...can't until probably tomorrow, unfortunately. but i'll check all the values.
in the pic, do you mean the 1u to the left of the 220, or the one above? the "empty pads" are actually where the 10k trimmer is mounted.
must have been a friday afternoon job, there's a big hole in the pcb to adjust the trimmer with.

i wonder if that 1u mistake vs the 10u that should be there is why it's not phasing?

what i'll try to do is tell you left to right what all the components are, and what row...there's from top to bottom basically 6 rows of components.

1-4 is mounted on a vertical axis,

row 5 is horizontal,
row 6 is again vertical.

hopefully, that will help sort the components out for you to finally crack this circuit.

thanks for the patience, bro...stay tuned!!

[Scruffie]

just checked again, my mistake...  .47, not .047 bro.

5 smaller transistors, 1 large one.

big one is marked 2n6290

small ones are 2n5088 next to the 4013bpc

2 2n5087's

1 2n3904

Do you mean 1 x 2N5087?

If so that checks out, if not, we have an extra 2N5087 for some reason.

scruffie,
i will get to this asap...can't until probably tomorrow, unfortunately. but i'll check all the values.
in the pic, do you mean the 1u to the left of the 220, or the one above? the "empty pads" are actually where the 10k trimmer is mounted.
must have been a friday afternoon job, there's a big hole in the pcb to adjust the trimmer with.

i wonder if that 1u mistake vs the 10u that should be there is why it's not phasing?

what i'll try to do is tell you left to right what all the components are, and what row...there's from top to bottom basically 6 rows of components.

1-4 is mounted on a vertical axis,

row 5 is horizontal,
row 6 is again vertical.

hopefully, that will help sort the components out for you to finally crack this circuit.

thanks for the patience, bro...stay tuned!!

To the left of the 220uF, to the right of the Vactrol first row above the horizontal.

Well funnily enough the trimmer's been on the bottom of every trace side shot i've seen of this, even a model that had seemingly had a slight PCB revision, guess they didn't like adjusting it through the board.

I wouldn't have thought that's why it's not phasing, while I don't entirely understand the LFO/Envelope section of this, that caps more to do with the envelope side of things.

It could be lots of things making it not work the CA3140 or CD4013 might have blown, both static sensitive and play a roll down in that section, the vactrols might have aged and died or in EHX fashion of the time, a bad solder joint somewhere (although that is a nicer looking job than normal) but that's random guessing.
Have to get some voltages going.

That would be brilliant if you could, I have a scan side shot of the track and component side so I can fill in all the values in PSP and trace it through with ease that way.

With all the resistor and cap values confirmed what was going on in the various schematics should be a lot clearer and make it clear what might be worth playing with because the discrepencies could be down to the fact the schematics all seem to be revisions and given i've seen a revised PCB layout and the first schematic I have is dated 78 and final schematic dates 1980 (your unit may just fit the 79 schematic I have as it has an earlier PCB revision) if you follow what i'm getting at.
May I ask if this unit has blue paint facia or not?

Thanks man! Should have another one cracked and a vintage unit repaired soon eh 

[pinkjimiphoton]

just checked again, my mistake...  .47, not .047 bro.

5 smaller transistors, 1 large one.

big one is marked 2n6290

small ones are 2n5088 next to the 4013bpc

2 2n5087's

1 2n3904


Do you mean 1 x 2N5087?

If so that checks out, if not, we have an extra 2N5087 for some reason.

yes, my bad....typo for a change instead of stupidity

scruffie,
i will get to this asap...can't until probably tomorrow, unfortunately. but i'll check all the values.
in the pic, do you mean the 1u to the left of the 220, or the one above? the "empty pads" are actually where the 10k trimmer is mounted.
must have been a friday afternoon job, there's a big hole in the pcb to adjust the trimmer with.

i wonder if that 1u mistake vs the 10u that should be there is why it's not phasing?

what i'll try to do is tell you left to right what all the components are, and what row...there's from top to bottom basically 6 rows of components.

1-4 is mounted on a vertical axis,

row 5 is horizontal,
row 6 is again vertical.

hopefully, that will help sort the components out for you to finally crack this circuit.

thanks for the patience, bro...stay tuned!!

To the left of the 220uF, to the right of the Vactrol first row above the horizontal.

Well funnily enough the trimmer's been on the bottom of every trace side shot i've seen of this, even a model that had seemingly had a slight PCB revision, guess they didn't like adjusting it through the board.

I wouldn't have thought that's why it's not phasing, while I don't entirely understand the LFO/Envelope section of this, that caps more to do with the envelope side of things.

It could be lots of things making it not work the CA3140 or CD4013 might have blown, both static sensitive and play a roll down in that section, the vactrols might have aged and died or in EHX fashion of the time, a bad solder joint somewhere (although that is a nicer looking job than normal) but that's random guessing.
Have to get some voltages going.

That would be brilliant if you could, I have a scan side shot of the track and component side so I can fill in all the values in PSP and trace it through with ease that way.

With all the resistor and cap values confirmed what was going on in the various schematics should be a lot clearer and make it clear what might be worth playing with because the discrepencies could be down to the fact the schematics all seem to be revisions and given i've seen a revised PCB layout and the first schematic I have is dated 78 and final schematic dates 1980 (your unit may just fit the 79 schematic I have as it has an earlier PCB revision) if you follow what i'm getting at.
May I ask if this unit has blue paint facia or not?

Thanks man! Should have another one cracked and a vintage unit repaired soon eh 

my pleasure.
i SHOULD have the whole day tomorrow to look at this thing...i gotta couple gigs that fell in my lap i need to prepare for (hey, i don't need to know the steeeeenkin' songs, i'm a LEAD guitarist, if i screw up, i'll scowl at the bassist!! )

yes, the faceplate is blue and black, and he said he bought it new in the late 70's.

thanks for the tip with the cap, i'll fix that, too asap.

i can kinda get the envelope to work, and phasing if i sweep the sensitivity knob, but it's almost non existant.

i will check my junk drawer, i think i have the proper chips kicking around.

thanks scruffie!

[Morocotopo]

Guys, i´m quietly following your work. Great! I e-mailed Scruffie some files that might be useful, so Scruffie, check your mail! Eventually, and hopefully with some help from me, we´ll all have a working Polyphase!

Regarding the thermistor, couldn´t we replace it with a trimpot? Even accesible through a hole in the box to make adjustments without opening it... ´cause a thermistor is a resistor that changes value with temperature, right? So...

[Scruffie]

Guys, i´m quietly following your work. Great! I e-mailed Scruffie some files that might be useful, so Scruffie, check your mail! Eventually, and hopefully with some help from me, we´ll all have a working Polyphase!

Regarding the thermistor, couldn´t we replace it with a trimpot? Even accesible through a hole in the box to make adjustments without opening it... ´cause a thermistor is a resistor that changes value with temperature, right? So...

Cheers Morocotopo, very helpful!

Well i'll be... only a quick glace but it appears the mixing resistors are actually 22k & 5k6 from the 1uF Negtive.

And yes, a trim would be suitable, I did find an alternative thermistor that could be used but I really dunno how necessary it is anyway unless you take your pedal through extreme temperature changes.

I'll work through later, with Jimis component notes, should be a breeze.

Edit:
This Thermistor is probably okay if the resistor value is tweaked http://www.taydaelectronics.com/thermistors/100k-ohm-ntc-thermistor-5mm.html
At 0c it's around 500k where as the original was 350k
At 25c it's around 100k same as the original
And at 50c it's around 50k where as the original was 33k

Not perfect but I bet it'd do if one required a trimmer.

[pinkjimiphoton]

hi brothers,

i'm just getting my shit together now, gigged last nite and hippy is burnt toast.

gonna get on this this afternoon, at least start to.

remember, my eyes are dodgy...so i'm gonna list the stripes on the resistors, sometimes i have a problem with certain bands.

but i believe we can get this thing going now. it'll be nice to fix my friends box, but even BETTER, be able to build our own!!

also..as far as i can tell, there's no thermistor on this thing anywhere...unless it doesn't look like the normal blue ones that look like a disc cap.

so...it's probably not even necessary, i'm guessing!!

gimme a little bit to get going...hippy's always slow after a gig.

[Scruffie]

hi brothers,

i'm just getting my sh*t together now, gigged last nite and hippy is burnt toast.

gonna get on this this afternoon, at least start to.

remember, my eyes are dodgy...so i'm gonna list the stripes on the resistors, sometimes i have a problem with certain bands.

but i believe we can get this thing going now. it'll be nice to fix my friends box, but even BETTER, be able to build our own!!

also..as far as i can tell, there's no thermistor on this thing anywhere...unless it doesn't look like the normal blue ones that look like a disc cap.

so...it's probably not even necessary, i'm guessing!!

gimme a little bit to get going...hippy's always slow after a gig.

Hope the gig went well!

Looking closely... I think those resistors I questioned being 18k or 180k are the 18k on the schematic, it's just a weird colour that doesn't quite look orange or yellow in any of the 3 model photos I have.

There is a thermistor from what I traced, it's near the trimmer and 3 trannies, it looks like some weird little black diode... when you get this working you could try warming or cooling it somehow and see what happens, might explain if it really is needed/why it is... it's to do with keeping that area biased at 6.7V for whatever reason it's unstable.

I've glanced a lot more with guess work and no tracing while I wait for your checks but I think other than those mixing resistors and what I recall of tracing this from really poor photos in the past, the 79 schematic is accurate... but we will see what other suprises this might have.

Take your time! I'm busy untill the new year before I can really get in to this at which point i'll label up a redrawn schematic and a PCB trace so checking should be easy.

[pinkjimiphoton]

cool, thanks for the patience. this damn flu has doubled back on me hardcore today, i didn't do squat but sleep mostly.

but...that said, i DO have it open on my bench. and i need to get it off there so i can do a couple paying gigs.

the gig was a gas...steep learning curve, i don't know a lot of "chick rock" and i got contracted to play lead for a band fronted by twin sister witches.

so...a lot of thinking on my feet, and bullshitting like crazy to get thru the nite..

luckily, i guess their normal lead player must not be too hot, cuz they left out all the more difficult changes...lol... like, crazy on you by heart, reduced to the least common denominator.

like...none of the bridges, just verse/chorus kinda stuff.

i got to get my yayas out tho some, used my talk box on sweet emotion (which i never ever played with a band before) and rocky mountain way...

and during the second solo of comfortably numb i had people throwing dollar bills at me like i was a stripper.

good times.

now...the thermistor... ok, it's on there... but i thought it was a ferite! cuz that's what it looks like. very weird!!

[Morocotopo]

Jimi, hope you get well.

I took advantage of some free time yesterday and today, and went ahead with the tracing and schem.

Here´s the cleaned schem just as the one Scruffie posted. Parts numbered.



Here´s the current trace, based on that schem for numbering:



I´m really close to finishing the tracing. The file posted is just for show, I´m doing it with Photoshop so I have the different elements (parts, labels, tracks) in different layers. Then comes the checking of values, then a prototype, then... making noise!

A few notes: I´ve found discrepancies in the mode switch, the one I based my tracing on (I believe it´s the one Mark Hammer had and took pics for me), uses, as far as I can tell, a single pole switch, not a double pole as on most schems. Those of you who have an actual unit, could you take pics of the switch and the wiring of that? None of the pics I have show that clearly.
The power section doesn´t have the two Q´s at the end and associated parts. The rest of the actual pedal so far is just as the schem, not taking into account values, that´s the last thing I´ll check.
Well, maybe tomorrow I can squeeze some time from the new year´s eve dinner preparations and finish the tracing.

And now, a teaser. Look what i found on my computer!

http://soundcloud.com/truemostro/polyphase-18v-pwr-supply-test

That´s a test of the one I made years ago with the Nelson layout. Never got the envelope working, but the phasing, as you can hear, was great.

EDIT: the schem looks crap, here´s the direct link, let´s see if that allows a reasonable quality download:

http://i68.photobucket.com/albums/i5/Morocotuco/EHPolyphaseredrawREV02_zps616b582e.png

EDIT 2: no, that didn´t work. OK, let´s see now:

[pinkjimiphoton]

Jimi, hope you get well.

I took advantage of some free time yesterday and today, and went ahead with the tracing and schem.

Here´s the cleaned schem just as the one Scruffie posted. Parts numbered.



Here´s the current trace, based on that schem for numbering:



I´m really close to finishing the tracing. The file posted is just for show, I´m doing it with Photoshop so I have the different elements (parts, labels, tracks) in different layers. Then comes the checking of values, then a prototype, then... making noise!

A few notes: I´ve found discrepancies in the mode switch, the one I based my tracing on (I believe it´s the one Mark Hammer had and took pics for me), uses, as far as I can tell, a single pole switch, not a double pole as on most schems. Those of you who have an actual unit, could you take pics of the switch and the wiring of that? None of the pics I have show that clearly.
The power section doesn´t have the two Q´s at the end and associated parts. The rest of the actual pedal so far is just as the schem, not taking into account values, that´s the last thing I´ll check.
Well, maybe tomorrow I can squeeze some time from the new year´s eve dinner preparations and finish the tracing.

And now, a teaser. Look what i found on my computer!

http://soundcloud.com/truemostro/polyphase-18v-pwr-supply-test

That´s a test of the one I made years ago with the Nelson layout. Never got the envelope working, but the phasing, as you can hear, was great.

EDIT: the schem looks crap, here´s the direct link, let´s see if that allows a reasonable quality download:

http://i68.photobucket.com/albums/i5/Morocotuco/EHPolyphaseredrawREV02_zps616b582e.png

EDIT 2: no, that didn´t work. OK, let´s see now:

ariel,
you are f'n godlyke. seriously. now it'll make my job easier. i'll start filling in values tomorrow. your layout with the numbering will make life MUCH easier...and especially to see what's what on the schematic. parts are all over the place on the board, i think the EH boys were doing some good lsd when they laid this board out!!

i went thru and re-soldered the whole damn board tonite. also replaced the 4013, gonna put another 1458 in there, too, see if it fires.

the wires were broken off the board going to the switch on the board end, so i MAY have it connected wrong...i was getting a little bit of phasing/envelope before, none now. i can't tell from my crappy pics where the wires were supposed to go. that may be why i can't get it to fire.

i will look at the switch, i think it's a dpdt, using both sides, as well.

thanks for the well wishes. with luck, i will beat this thing. it's been kicking my ass for a couple weeks now.

[pinkjimiphoton]

i reflowed every joint on the board, put the correct value caps in, and replaced the cd4013b. i think the ca3140e may be hosed tho.

i'll start reading the resistors tomorrow. hopefully these crummy pix of the switch and wiring will help in the interim.
tried printing the layout posted, dang printer ran out of ink. nice.

so that's pretty useless  for me for now, til i can get more ink.   

[Scruffie]

i reflowed every joint on the board, put the correct value caps in, and replaced the cd4013b. i think the ca3140e may be hosed tho.

i'll start reading the resistors tomorrow. hopefully these crummy pix of the switch and wiring will help in the interim.
tried printing the layout posted, dang printer ran out of ink. nice.

so that's pretty useless  for me for now, til i can get more ink.   

No time to reply to everything posted here properly (although nice job Morocotopo!) but while the CA3140 is a MOSFET opamp (I assume chosen for good reason) if you don't have one on hand a standard single opamp (741?) might work to test it at least, worth a shot.

Oh and to note that switch conforms to the schematic entirely.

[pinkjimiphoton]

i hope the switch does, cuz i wired it to the schematic... no way to tell if it was right, but i compared it to the pics i took before the wires broke, so it should be good.

i think it's working...should i be seeing modulation on the lm324? it's modulating up and down on a couple of the pins there.

but there's something funky. some of the stuff on morroccotoppo's layout is still off a little.

we'll get it sorted out.

it appears to me, that there's  a lot of resistors on the board i have that don't match up with any of the schematics.

bear with me, and i'll get it...

thanks for the tip on the 741...i don't have any of them at the moment i don't think, but from what i'd researched they aren't swappable.

onwards and upwards..... 

[Scruffie]

i hope the switch does, cuz i wired it to the schematic... no way to tell if it was right, but i compared it to the pics i took before the wires broke, so it should be good.

i think it's working...should i be seeing modulation on the lm324? it's modulating up and down on a couple of the pins there.

but there's something funky. some of the stuff on morroccotoppo's layout is still off a little.

we'll get it sorted out.

it appears to me, that there's  a lot of resistors on the board i have that don't match up with any of the schematics.

bear with me, and i'll get it...

thanks for the tip on the 741...i don't have any of them at the moment i don't think, but from what i'd researched they aren't swappable.

onwards and upwards..... 

Quote the Datasheet 'Directly replaces industry type 741 in most applications' while it may not work right (The CA3140 does have certain properties over it) it might work enough. I'd try TL071, NE5534 etc too if you have one, no harm trying.

Yeah you should see modulation on the 324.

There are a few values I can tell off from the schematic, but not many, I have about 5-7 resistors in question (cap values I can't answer for) 3 definitley don't match. Otherwise mainly fine.

I haven't checked morocotopos layout yet, i'll provide one when time provides.

[Morocotopo]

Jimi, thanks for the pics.
Well, I got kind of obsessed with this, so I finished the tracing.

I worked from this pics, provided by Mark Hammer, filling in the parts below the pots with the other available pics:





The files:







The schem:



This schem is with a single pole mode switch, wich I believe Mark´s version uses. I seem to recall seeing some original schems with a SPDT, but who knows. Here´s the schem with a DPDT:



Well, there´s no ovbious discrepancies between schems and actual units, as far as I can see. You might want to recheck my work, the more eyes the better.
Now I´ll start to check parts values with all the pics, I think, judging by what you guys posted, that in that part of the work I´ll find some discrepancies.
Notice that with the PCB tracing we almost have the PCB done...
Anyway, once breadboarded and confirmed to work, I´ll probably design (or try to...) a smaller PCB.
Signing off for the day. Have a happy new year!!!

[pinkjimiphoton]

that's absolutely a different model from what i have bro.

mine has a double pole double throw switch, and it hooks up on one side to the envelope sensitivity knob and the rate knob.

interesting. gimme a little bit, i gotta dig my cars out of the 8 inches of snow or so they're still buried in, and get an amp done this afternoon for someone to be able to use hopefully tonite.

then i'll start reading values. i'm gonna try and take pics and label each part...probably be a lot of pictures.

happy new years to all!!

[Morocotopo]

Jimi, seems there were a few versions of the thing. But the changes are not that drastic anyway, at least the schem, not speaking about values. Hope the second schem is what your unit is.

[Scruffie]

How you gettin' on there Jimi? Unit up and running yet?

Morocotopo, as I mentioned, I think from tracing (and your pictures confirm I got the right resistors, thanks for that! Makes it much easier to follow) the mixing resistors are actually 22k, not 3k6 and the 15k pull down being 5k6 which would be a discrepancy, that's the only one I could be near-sure of that might not just be the band colours not showing up great on camera.

Also R35 on your overlay, should be 43k, looks like Red, Orange, Orange, Yellow? A Yellow could be mistaken for gold making it 23k but a Red Tollerance band?