Pearl PH44 schematic?

[tubegeek]

Dino and I have built it but the PCBs aren't available, we haven't finished verifying the build.  It needs a boat load of matched transistors which is a pain

Thank you!

[Mark Hammer]

Dino and I have built it but the PCBs aren't available, we haven't finished verifying the build.  It needs a boat load of matched transistors which is a pain

Thanks for the correction.  I see the board listed on the site and thought things had progressed further than they actually had.  My bad. 

[digi2t]

Yes, we did make a board for it, however.....

while I have managed to get phasing, or some semblance thereof, it's far from OK. The sweep of the phase is pretty funky, and nothing like the original. Some research on it revealed a circuit analysis done on a Japanese site. Apparently, all of the stage transistors need to be matched. There's also some other transistors that need matching as well. How tight, and within which gain range, is unknown.

Next up is the 3080. Bad enough that they're starting to get rather pricey, I've also found that they seem to have their own tolerance issues. Not much fun if one has to buy more than one just to audition for the right one.

Third, there's the 2SC1583. Again, kinda pricey, and fakes are plentiful. Probably fake-able with something else, but with the aforementioned issues, I haven't even gotten to any proper substitutes for it. I have a proper 1583 in there right now.

Finally, the speed control isn't working right. Yes, I do have proper transition between fast and slow, but the fast speed is stupid fast, even at it's slowest setting. Of course, when the phase is all wrong to start with, it's hard to really give a shit about the rest of the shopping list.

With this many issues, I've decided to shelve the project for the time being. Perhaps I'll come back to it at some point, but for now, it'll keep the Rand-o-matic clone company. We've got enough other project to keep us going for a good long while.

[Mark Hammer]

Sorry to hear you've encountered so many obstacles, Dino.  Pity.  It's a fun phaser, which is clearly the impetus for wanting to clone it.  I suspect the Japanese site/info is that of Osamu Hoshuyama, who first drew the PH-44 to my attention when he was staying here in 2003.