mother@#$%ing tonepad phase 45... :(

[deadastronaut]

I can also definitely say that I didn't match any Fets and mine sounds great. Might have gotten lucky.

you must have...the last one i built was fussy too...!. i'll build the matcher on vero anyway..

[R.G.]

here are my voltages on the 2x tl072's...

OK, those look pretty close to OK, excepting that pin 1 ought to be popping up and down.

How 'bout those JFETs and the Zener? The LFO capacitor?

[DougH]

When I built my phase 90, the zener was very critical. Even if the fets are matched, wrong zener voltage can sink the ship. I breadboarded mine before I built it and it allowed me to test different zeners (different voltages) I had in my stock.

[deadastronaut]

here are my voltages on the 2x tl072's...

OK, those look pretty close to OK, excepting that pin 1 ought to be popping up and down.

How 'bout those JFETs and the Zener? The LFO capacitor?

pin 1 on the O72.. 1.33 - 8.45. SUDDEN JUMP..

zener is ...3.10v
j201 LEFT.
G   2.60-2.79
S   3.10
D   3.10

RIGHT.
G  2.03-2.53
S  3.10
D  3.10

[R.G.]

pin 1 on the O72.. 1.33 - 8.45. SUDDEN JUMP..

OK.

zener is ...3.10v
j201 LEFT.
G   2.60-2.79
S   3.10
D   3.10

RIGHT.
G  2.03-2.53
S  3.10
D  3.10

Hmmm... why are the gates different voltages? And why does the left one change by 1.9V while the right one changes by 0.5V?

[deadastronaut]

no idea!....i'll double check everything..

meanwhile heres a quick vero of your fet matcher...does it look ok?..



my G'S on the fets are both 2.25-230 now!...

[deadastronaut]

(havent seen the cat in a while)...  

[deadastronaut]

 

[deadastronaut]

did another layout of the fet matcher...using the schematic... yep should be 47uf..

[R.G.]

'K, so what are your pin voltages now?

[deadastronaut]

 i went back to breadboard and breaded the matcher  as per the scheme to be double sure....


edit: got it working....

my fets j201's are reading (on 2 volt setting on dmm)

.061
.090
.103
.051

do these readings look normal?...


edit: the nearest matchers were .074-.077


i found 2x 2n5952's

reading. 1.533 and 1.542...these look like my best bet i guess!...

[deadastronaut]

heres my tlo72 v's...

left 072..

pin 1   3.07
pin2    3.09
pin3    3.08
pin4    0v
pin5    2.96
pin6   3.10
pin7   3.10
pin8   9.09


right 072.

pin1   3.25-591
pin2   4.43-4.90
pin3   4.09-4.90
pin4   0v
pin5   3.08
pin6   3.09
pin7   3.10
pin8   9.09

[deadastronaut]

@#$%ing hell.....seems like ive been on a wild goose chase!...ARGHHHHHHHHHHHHH.........................................................

i stuck these 2n5952's in the way it says on the layout...and it @#$%ing worked!!!!!!!....not backwards!...how the hell is that!...

i'm sure on my previous build i had to reverse the fets???......weird!... but hey its working at last!...lovely..

thanks for your help guys...and my cat is safe for now.. she's not looking so nervous!... ....till my next build!..

plus i ended up with a fet matcher too!.and learning that !.......result....

NOTE: the phase only kicks in on the very end of the 250k trim....do you think i should try a higher trim vvalue to get more of a sweet spot range?...

[R.G.]

@#$%ing hell.....seems like ive been on a wild goose chase!...ARGHHHHHHHHHHHHH.........................................................

i stuck these 2n5952's in the way it says on the layout...and it @#$%ing worked!!!!!!!....not backwards!...how the hell is that!...

i'm sure on my previous build i had to reverse the fets???......weird!... but hey its working at last!...lovely..

Good work! I've done so many forehead slappers that my forehead is getting flat. And it's the silly stuff that bites you, stuff that's too simple to be wrong. Or it's that way for me.

NOTE: the phase only kicks in on the very end of the 250k trim....do you think i should try a higher trim vvalue to get more of a sweet spot range?...

Depends. Changing the pot value won't change things much. What that is telling you is that the voltage on the JFET gates only gets into the variable resistance region at one  end of the pot travel. Question is - which end? Turn it to phasing, then measure the voltage on the pot wiper. Is it nearly the zener voltage or nearly ground?

[deadastronaut]

cheers RG...what gets me is that on the tonepad build reports everyone had to turn them round!...

so i shouldn't have needed to slap my head!....but i have anyway as a matter of course!..

oh well, it works, so i'm a happy bunny, and so is my cat!...

its a really nice subtle phaser!..great!..now to whack a rate led on pin 1 (right 072) to resistor to ground in case someone wants to know.....thanks again guys!..

[Fender3D]

Great Rob...
Phase 45 is one of the best vintage phase sound available.

PS
as for the cat:
if you can squeeze her in a 1590BB I'll owe you a beer 

PPS
I 'm just curious to see where you'll put the stompswitch....

[deadastronaut]

 

poor pussy!...

[chromesphere]

Hey Deadastronaut,

Sorry to hear about your troubles with the p45.

I just finished my p45 yesterday.  Didnt match.  Used j201's (which are positioned 180 degrees if your looking at the tonepad layout).  I tried, 4 different j201's, they all worked!  Couldnt hear much difference between the 4...

And if that isnt enough, i'll go on by showing you a photo of her.  She's beautiful. I already posted it in the pictures thread...but im so proud...

Ggood luck!  If you need readings / info, let me know, ill check it for you!

[deadastronaut]

cheers man!..

yeah that looks nice!..

i havent tried j201's again since i got it going on the 2n5952's.(the layout way round!)...i'll give it a go , see what happens....

lovely little phaser..really clear/ crisp sound...

you didnt fancy the rate led then..?..i like flashing lights...

[chromesphere]

edit: sorry didnt read the bit you actually got it working!  lol  Thanks for the compliment to btw.

Flashing LED: Not sure if i wired it up wrong, but the LED wouldnt switch off when bypassed.  I also didnt like the way the LED flashed robotically as well (not smoothly).  I think i was tapping into one of the pins on the op-amp from memory.

Paul