Magnavibe question

[duck_arse]

kinda yes, yr right. the idea was to have a high range pot and a low range pot so he could set two speeds and switch between them. we were designing with the values he had to hand, you can go up and down ranges if you want still more, or still less. 3pdt, yes. there is plenty you can try, plenty you can mess with, plenty values you might like.

note the Y.Z drawing caps are not polarised, and the X.Z drawing caps ARE polarised, and are connected a little funny, for maintaining correct polarity.

keep us updated with what you find.

[Plexi]

kinda yes, yr right. the idea was to have a high range pot and a low range pot so he could set two speeds and switch between them. we were designing with the values he had to hand, you can go up and down ranges if you want still more, or still less. 3pdt, yes. there is plenty you can try, plenty you can mess with, plenty values you might like.

note the Y.Z drawing caps are not polarised, and the X.Z drawing caps ARE polarised, and are connected a little funny, for maintaining correct polarity.

keep us updated with what you find.

Great idea Duck!

I tried with 470nf no polarised caps, and add 1uf electrolitic in parallel, for a total 1470nf (1,47uf)
Te results are awesome: I don't know wy, but it have a natural small speed swell... not abrupt speed change.

[Plexi]

Ok... some tweaks, and a short nap, I have some news.

The slowest it can go without loose the vibe.
470nf + 2.2uf (parallel) in both C5 and C7

The fastest it can goes.
470nf in both C5 and C7: maybe 200/300nf can reach more speed, with 100nf it stop.

As you can ear at the 0:27 of the fast video, I bypassed the .22uf cap (someone use .1uf) right next to the ldr: the one before the vibe/trem resistor.
It produces a super square tremolo.

[duck_arse]

are you happy with the ranges? I think the super-chop might be from the oscillator sweet-spotting, where everything comes together for MAXIMUM signal output, which I noticed today messing on the BB. when you change caps, you should be scaling the whole string, don't put 2*100nF with 2*2u2, they are probably too far apart value-wise. 2u2 and 470nF or 560nF maybe, 100nF and 680nF maybe, like that.

they are supposed to all be the same, but that can produce an output PEAK which will DISTORT the sinewave, so amp manufacturers used to put three different value caps in, to spread the range and even out the response.

another method of range switching is to switch the values of the resistors to ground - I had 68k in series with 22k, and switch/short across the 68k (with 4*680nF and 220k pot) gave me 2.2~5Hz and 5~8Hz. just the oscillator tho, not connected to anything.

[Plexi]

You're right Duck.
Yes, I like it; you have a nice difference in speed. The slowest in "fast" mode is more fast than the fastest in "slow" mode.
When I tried with 470nf and 4.7uf (a huge difference) the led stopped. And start again in a few minutes.
It didn't happen when I put a high value in C5 only
Maybe I'll get better results with 470nf/1uf in C5, 6, and 7.

[duck_arse]

excellent!