ROG Phozer - LFO won't work! [SOLVED]

[Cortexturizer]

http://www.runoffgroove.com/phozer.html

I have the board etched and have built the entire thing, LFO won't move an inch. After countless hours of troubleshooting I decided to breadboard it - no improvement. It behaves the same as on the pcb. The LED stays lit and nothing happens.



I mean look at this thing, I have never seen a simpler one. Doesn't work for me. I do get voltage oscillating before and after the 6k8 resistor, but not at the end output.

What am I missing?

[midwayfair]

hrm. Wrong pin for the buffer input?

[Cortexturizer]

nope, pin 3 on both the pcb and the breadboard :/

[mgwhit]

I do get voltage oscillating before and after the 6k8 resistor, but not at the end output.

What about on the input pin of the second op amp?

nope, pin 3 on both the pcb and the breadboard :/

And are you using pin 5 for the input to the second op amp?

[Cortexturizer]

A total dead-end. I am starting to wonder how has anyone ever built this.
MAde the LFO section ten times on breadboard from scratch, no changes, every time I get the same thing as on the pcb, constant voltages without any oscillating. I get the usual voltages (showed as if you were looking at the IC with the pin 1 on left top corner):
4.6   9.2
4.6   4.6
4.6   4.6
0.0   4.6

Could someone PLEASE breadboard the LFO section when they get some time on their hands? I would really appreciate it. Thanks

[midwayfair]

Try making the LFO from the Shoot The Moon. It's almost identical.

I have something almost exactly like that LFO on my breadboard at the moment and it works fine. I even had the 500K pot in there at one point.

[brejna]

I've just tried phozer lfo and it doesn't work..

[midwayfair]

This is hardly the only pedal that LFO is used in. I absolutely, 100% assure you that the LFO as drawn works.

[Cortexturizer]

Well I've breadboarded the STM LFO and it works perfectly with no hassle whatsoever. Fired first try. I've experimented on it and it's great.

The only difference to the Phozer LFO is how the rate pot is connected in relation to the 6k8 (2k2 in the smt lfo) and the biasing network 150Ks instead of the 220Ks. I have already tested the different Rate pot arrangement and it still the same - it doesn't work. Could it really be down to the 150/220K difference? I have no 220Ks to try it out :/

I used the same components to breadboard the STM lfo that I've previously used during my failed attempts on the phozer lfo, same chip, same capacitors, same rate pot, everything.

[midwayfair]

Could it really be down to the 150/220K difference? I have no 220Ks to try it out :/

Could be the chip you're using. You can use any large resistor ... though 100K should be sufficient. You can even use 1M if you want. It shouldn't actually matter.

The speed pot is wired the same, it's just drawn differently or has other parts in the way. The Lune LFO is directly derived from the LFO in the Phase 45 etc. (The same LFO is, I think, also in the MXR Chorus and a host of other MXR pedals.)

[Cortexturizer]

I just put the chip from my Phozer pcb to the breadboard instead of the one I was using for the STM lfo. Works perfectly on the breadboard. Didn't work earlier when I was breadboarding the Phozer lfo. Devil's work I tellz ya...

[Cortexturizer]

Just wanted to say that the Phozer LFO works perfectly and that it was, of course!, my mistake of some sort...

Interesting effect this Phozer thing. I am using the VTL5C2 and it is very very lush. I wouldn't shy away from this one if you're into phasers guys.

Cheers