Phaseur phlegm

nosamiam · July 19, 2005, 02:36:25 AM

Hey everybody,

I've just ended a long night of twoubleshooting and tweaking my 4ms Phaseur Fleur. I actually built it several months ago on perf but it kept falling apart, so I PCB'ed it. Much more sturdy

It never worked too well and after a while (on perf) it just plain stopped working. Well now it's up and running and sounds great!!

.... for about 30-40 seconds

Then it starts to gate/distort/break up. It loses volume and phase effect until it totally farts out--all within the span of about 15 seconds. So it works great, then begins a 15 second fart sequence. I've found that if I unplug the stereo input jack for about 5 seconds and then plug it back in, it fixes the problem. Also, if I turn the pots (can't really put my finger on which ones, exactly) back and forth a couple of times, it sometimes helps.

Anyone ever run into something like this before? I'm guessing it has something to do with transistors or caps? Any ideas?

RickL · July 19, 2005, 12:06:49 PM

I had exactly the same problem with the first Phaseur I built. I fooled around with it for a couple of years with no success and finally built another one from scratch which worked perfectly.

I took yet another go at trouble shooting the first one and finally found a wiring error. I think I soldered the end of one of the jumpers to the wrong place on the board. Recheck all the jumpers and check for shorts on the circuit board, it's pretty crowded on there.

Rick

Jaicen_solo · July 19, 2005, 12:38:17 PM

Sounds like you've got a cap charging something. Given the time delay, it's possibly a large filter cap which may be backwards.

nosamiam · July 19, 2005, 01:33:03 PM

Ok, you guys have given me some great leads (no pun intended). I'll take a look when I get home. Anyone else?

britt-stinker · July 19, 2005, 02:20:18 PM

Instead of starting a new topic, Im just going to ask in this one.

What exactly does the Aux LFO (to add to main) And Aux LFO (to modulate main) do?

nosamiam · July 19, 2005, 11:27:57 PM

Thanks for the help folks. Got it working. I had missed a couple jumpers. They're hard to see in the layout. Once I put those in and did a bit more trimpot tweaking, it started to sound really good. I'm pretty much there now. Thanks!!

Britt,
Couldn't tell ya what the mods do. But I'm kind of curious myself.

RickL · July 20, 2005, 01:14:23 AM

I'm guessing but here's what I think. Aux LFO (add to main) is a second LFO in parallel with the first, both acting on the filter sections. You could set it up with the first LFO doing a slow sweep and the second doing a fast warble imposed on top of the slow sweep.

The Aux LFO (modulate main) should change the speed of the main LFO up and down. With the Aux LFO speed set slow and depth set high the Phaseur speed should gradually change between fast and slow. Set the depth lower and the speed should change less.

I haven't added these mods to my Phaseur yet. I'll have to put them on my 'to do' list.

nosamiam · July 20, 2005, 04:18:59 AM

RickL, what you say makes sense. If true, those sound like some GREAT mods! But I'm so happy with my box layout, I don't wanna mess it up with more knobs. I think I'm gonna wait till I build another one someday. Thanks for solving the mystery though!

rocket · July 20, 2005, 07:20:16 AM

nosamiam - have you already finished your HP? :mrgreen:

nosamiam · July 21, 2005, 06:41:34 AM

HP?

rocket · July 21, 2005, 05:10:11 PM

Harry Potter - I supposed "phlegm" instead of "fleur" was a reference to the 6th Harry Potter book

britt-stinker · July 22, 2005, 03:14:36 AM

I have some questions:
The 100 Resistor on Aux. LFO (add to main LFO)http://commonsound.com/phaseur/auxlfo_add.pdfThe one that just saids 100), is this a 100K or 100R(OHM)??

And what kind of CdS cell should i use for the Aux LFO (to modulate main)http://commonsound.com/phaseur/auxlfo_modulate.pdf? Just the same like the one on the main board?

Thanks for all your help

RickL · July 22, 2005, 11:00:01 AM

It's a 100 ohm resistor. Note that it's in series with the speed pot. It just prevents the total resistance controlling the speed from ever getting less than 100 ohms. You could replace it with a 100 ohm trim pot and adjust for the minimum usable resistance if you wanted to.

Use the same CdS cell as on the main board.

nosamiam · July 22, 2005, 09:08:25 PM

Nope, not a Harry Potter reference. It was more of a description of the sound I was getting out of the thing. It sounds much better now.

I finished it Wednesday morning at about 1:30am and used it later that same day to record a keyboard part for my band's E.P. I love it when I make a deadline!

Here's how it turned out:

80k · July 22, 2005, 11:40:48 PM

i've made two phaseur fleurs and both of them required some serious trouble-shooting. keep at it, triple check all the joints, and use that multi-meter

it's a great sounding phasor, but not easy to tweak. run 2 of them in parallel for some seriously awesome sounds (i built two of them into the same box).

nosamiam · July 23, 2005, 06:51:22 AM

The producer that was recording us was so impressed, he asked me if I could build a stereo version with left and right ins and outs, left-channel-only option with stereo outs, and syncable LFO's!! Yikes!! Of course I told him, "Hmmm.... no problem."

ethrbunny · July 24, 2005, 11:18:03 AM

I built the PF with both extra LFOs.. and indeed the tweaking is proving to be a long term project.

To see a circuit with synch-able LFOs look at the commonsound layout for the 'tremulous panneur'.

nosamiam · July 24, 2005, 03:51:58 PM

Yeah, I was planning on using that as the way to go. I think I should be able to figure it out. It's gonna cost him though! Big enclosure, not one but two Fleurs with all the associated components. And hours of tweak-time fun!

rocket · July 26, 2005, 11:55:17 AM

Very funny though - in the book a person named fleur is called phlegm.

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Phaseur phlegm