yet another phase 45 built report!

[vdm]

hey everyone,

i decided today that i would ditch all the distortion and overdrive and fuzz and crunch pedals that i'd started, and get something that my parents would hear and go - hey that's different!

and after all the talk about the phase 45 around here, i went down to the local shop and picked up all the stuff to get one running (bar the switch and box)

i got it all together in one marathon 4 hour session, and used the univibe caps, and added a blinking led and got the pot to do the blend on clean/vibrato but i forgot to put it in while assembling, so it's waiting for a later day

i did the whole thing on perf using tonepad's layout as a basis, with a few obvious variations.

when it was all ready to go, i plugged in an opamp (i only socketed the first one, because i think the second is just an oscillator and doesn't affect the sound as much), i used a burr-brown - but i'll try a TL072 and it'll probably sound the same to me :?

i got clean sound straight away with no problem, but there was a little distortion when i hit the strings really hard - that problem still remains - and is my only niggle about the whole project

i went through about 8 fets in the Q2 position, and found where on the trimpot it went into focus.

the first one i tried was not good as i didnt get any phase throughout the whole turn of the trim pot, so i reversed the orientation and still nothing.
after going through them all though i had a pair matching at 10 oclock and 3 at 12 oclock. the ones at 12 seem to sound better though.

the phase is nice - and the blinking led is great fun too - very nice and smooth, good for nice rhythm stuff. the super slow setting is really cool for rhythm and also add's a little bit of interest to a boring distortion sound for solo's. with the faster speeds it does get pretty psychadelic - but with any kind of high gain distortion it seems to lose the effect... but i havent tried running the distortion before the unit - that might make it do a bit more.

so that is my report - and if anyone has any advice about the mix pot - as to whether it's worth it, and if anyone knows what could be wrong with the first couple stages that's making it distort with hard playing (even my cruddy squier with really weak pickups), it'd be a great help.

thanks,
trent

[Danny G]

"...and got the pot to do the blend on clean/vibrato but i forgot to put it in while assembling..."

What exactly does that mean?  I'm building a Phase 45 for my wife and I'm using the same layout (Tonepad.com).

[RDV]

"...and got the pot to do the blend on clean/vibrato but i forgot to put it in while assembling..."

What exactly does that mean?  I'm building a Phase 45 for my wife and I'm using the same layout (Tonepad.com).

This: http://www.lynx.bc.ca/~jc/pedalsPhase45.html

RDV

[vdm]

thanks RDV;)

always makes it easier when someone answers questions before you even know they're there  :wink:

im still having the distortion problem with any decent sized input... and im guessing its in the first stage - well involving the first opamp.

i had to use 510k resistors instead of the 470k because the shop was out of 470's. maybe this is effecting the voltage on the first pin of the opamp and mis biasing it or something.... as you may be able to tell - that's a complete stab in the dark, but all i know is there's distortion and i have no idea what could be causing it... so even a tip as to which componenets (or lack of components) would cause this to happen would be great.

i think i might try the mix control today.. see if i can work it in without destroying the board *too* much

trent

[RDV]

I've got a roll of 5000 470k, too bad it would cost so much to ship there, I'd give you some. I don't think that's it though. I used a TL072 in mine, but I don't think a BB OA should make it distort, seems like that would give it more headroom IMO. Problem is, I'm no EE, if it's not a simple solution, I'm not a lot of help. Hopefully one of the brainier types around here will chime in.

RDV

[vdm]

well i think i've found the problem... but still can't fix it  :wink:

the battery is old, i know this because a few months ago i but it in a 3leggeddog and it oscillated like crazy, so im guessing the thing is about to die now. so hopefully when i can get a fresh battery it'll be fine.

i tried a 4558 in IC1 slot and i couldnt hear any real difference - so i left in for sake cheapness. i also just did the mix mod and despite it being a fairly subtle phaser, it's nice to be able to dial in exactly how noticeable the phase should be. i know it probably doesnt *technically* adjust the amount of phase - but that's what it sounds like to me. The full vibrato is also interesting at higher rates, but is unnoticeable at lower rates.

overall im quite pleased with the build, and it's nice to know that in 24 hours ive pretty much finished the innards of an entire pedal (and got supplies for too many more :? )

now i just need to make an enclosure... probably another homemade job unless i can find myself a supplier of hammond sized boxes for not insane prices...

thanks,
trent