Phase 45 question

lightningfingers · June 12, 2004, 01:06:47 PM

OK I got all the parts, and they're on the perfboard and i'm about to solder them, but before I do, the FETs have'nt arrived yet (i'm using sockets) If I plug the circuit in without them (assuming I have'nt shorted anything/screwed the wiring up/used non-conductive solder :wink: etc.) I should still get a buffered guitar signal w/ no phase, correct?

RDV · June 12, 2004, 01:09:38 PM

YES

RDV

lightningfingers · June 12, 2004, 01:12:57 PM

Cheers :mrgreen:

ildar · June 13, 2004, 01:33:47 AM

Will Small Bear (or any other vendor) match FETs? I tried the phase 45 and got no phasing whatsoever with unmatched ones.

RDV · June 13, 2004, 03:50:23 AM

Quote from: ildarWill Small Bear (or any other vendor) match FETs? I tried the phase 45 and got no phasing whatsoever with unmatched ones.

No, he won't as yet. Are you 100% certain of your pin-out? Because tonepads layout is backwards if you use the recommended J-FETs. I got some phasing when I plugged in one J-Fet. I found the one J-FET that had the strongest phase, then plugged in all the others till I found a good match. It wasn't that hard. Check the pinout of the datasheet of what you've got versus the layout.

RDV

audioguy · June 13, 2004, 10:31:25 AM

Quote from: RDVBecause tonepads layout is backwards if you use the recommended J-FETs.

Thats good info because this was next on my build list! Whos layout do you recomend?

Thanks

Audioguy

RDV · June 13, 2004, 12:57:37 PM

Quote from: audioguyWhos layout do you recomend?

Don't get me wrong, Tonepad's layout is quite good. The DSG orientation works for 99% of the JFETs out there. If you use 2N5952(the recommended JFET) though, you just have to plug them in backwards, which is easy enough, and if you use J201, MPF102, 2N5457, or almost all the rest of them you plug them in like the layout says. I love all of FP's layouts and PCBs(I've bought one, and thinking about more), but I've had to point out that one little niggle, cause there's been guys who gave up trying to make it work till they found this out, then got them happening.

Regards

RDV

ildar · June 13, 2004, 02:04:04 PM

I used Tonepad's layout, made a PCB from the page. I was aware that the FETs were oriented backwards and made the adjustment.
There might have been something else wrong, though.
In a fit of frustration (and no sleep), I pulled IC2 while plugged in (not smart I know), and still got signal-unphased signal, but it was identical to the signal with both ICs.
I checked, and checked, and checked again, and all soldering was solid. There were no broken copper lines and no solder overlap.
Bad juju, maybe?

RDV · June 13, 2004, 03:34:13 PM

Your oscillator ain't oscillating then. Without seeing it all I could say is check your cap orientation. You could post your voltages.

Good Luck

RDV

ildar · June 13, 2004, 04:57:54 PM

Yep, did that too...flipped them all just in case, then flipped them back when it made no difference.
I can see that I'm gonna need to buy a multimeter. Since this is just a hobby I don't want to go for the top of the line unless necessary. Any suggestions on a model?

RDV · June 13, 2004, 10:40:20 PM

Quote from: ildarI can see that I'm gonna need to buy a multimeter. Since this is just a hobby I don't want to go for the top of the line unless necessary. Any suggestions on a model?

I bought one that was on sale for cheap at RS. It won't measure resistance over 1 meg though, which is a bummer.

RDV

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