John Hollis Ultraflanger

[Devius]

Anyone build one of these? I have all the parts but I want to know if theres anything I should be aware of before I build it.

[hannibal827]

Yes.  Common issues are ticking, noise, distortion, and proper biasing. 

Search this forum for "ultra flanger" and you'll get four pages' worth of results.

[Devius]

My first build was the hollis easyvibe using the 2 quad opamps and its got ticking issues as well. It actually ticks when I use the hot channel on my amp and the effect isn't even on. I'm pretty bummed but I love the effect.

[hannibal827]

That is more ambitious than my first build!

Look, the Ultra Flanger has its limitations, but it's fun.  You should definitely play around with it on the breadboard before you build the pcb.  That way you can see which of the aforementioned issues you will actually encounter. 

If you do get ticking--not everyone does--I would suggest sticking a 1-10uF cap between the LFO bias (3.8v) and ground.  That solved the problem for me.

Good luck!

[Devius]

I notice you've built the big muff pi? Did you build the stock version?
I built the creamy dreamer using sabrotone.com layout and it seems quite bassy. The high end doesn't seem to cut through as much either.

[hannibal827]

Yes, I built it stock.  I tried it on the breadboard with the 100nF coupling caps instead of the stock 1uF coupling caps.  I wanted to see what all the fuss was about.  The difference in bassiness wasn't noticeable to me, and bassiness doesn't really bother me much anyway.  So I went stock.

The small caps in the feedback loops are supposed to be 500pF but of course you have to move heaven and earth to find that value, so you're really choosing between 470pF and 560pF.  I went with 470 because even with the lesser amount of treble reduction I didn't find it too trebly.

Knowing me I will probably build the Ram's Head and Russian versions sooner or later anyway.  I am finding that I am a sucker for discrete fuzzes, to the point where it keeps me from doing other builds I want to do. 

Let us know how your Ultra Flanger goes.