This switching will pop, right?

[strungout]

Hey.

Is there a better way to do it with a 4PDT? I want to switch in 4 caps in parallel with four others in my Magnavibe build, to get slower or stock  speed options.

I'm not opposed to using 2 switches...

Hope you guys can make it out through that photobucket INKmark...

[duck_arse]

can we see the circuit diagram? switchings in the oscillator should not cause any pops.

[strungout]

can we see the circuit diagram? switchings in the oscillator should not cause any pops.

Hmm, thanks, didn't think about that. Usually when we talk about popping, it's always a cap in the audio path. So I guess it will discharge once the cap is connected but it won't make it into the audio signal cause they're not connected...

Here's the schem:

I added another pole to the pso just because I wanted to see what I'd get and it seemed to have smoothed out the transistion between high and low.

[PRR]

As said, switching the LFO won't "POP" in the audio. However it may burp the LFO bias so the LFO cuts-out for some period of time (~~part-second).

In this plan, only the end caps really see DC, the two in the middle should be fine without anti-pop.




> I added another pole to the pso

That reduces the range that you can get. With this pot range, a 3-stage allows 1.9:1 range; a 4-stage allows 1.6:1 range.

[strungout]

As said, switching the LFO won't "POP" in the audio. However it may burp the LFO bias so the LFO cuts-out for some period of time (~~part-second).

In this plan, only the end caps really see DC, the two in the middle should be fine without anti-pop.




> I added another pole to the pso

That reduces the range that you can get. With this pot range, a 3-stage allows 1.9:1 range; a 4-stage allows 1.6:1 range.

Paul: Thanks for the diagram! I will do that.

So, the 1uF cap + 1M5, across base and collector, is the third pole then? Means I misread the schem. I read that two poles is technically enough, but it won't reach a full 90 degrees per stage to get 180 total. But 3 stages of 60 will get you there. Thought there was only two poles. Ha.

Think I'll rebuild it with stock values on my BB and re-do my mods one by one to see which/if they really did make a difference or not. The phrase "you hear what you want to hear" is running around my head a lot lately

[PRR]

> the 1uF cap + 1M5, across base and collector, is the third pole then? Means I misread the schem. I read that two poles is technically enough

The 1.5Meg is Miller-Effected by transistor gain to something near 10k like the other poles.

2 stages could only work with infinite gain. 3 stages can work with gain like 28. 4 stages can work with some lower gain.

A several-stage R-C network with only one variable part will not make a lot of range. Making that part more-variable requires more gain and drive. If you had a 3 or 4-gang pot you could vary frequency linear with pot resistance. But the range needed for trem is usually small, and 1-gang pots are SO much cheaper...

You could consider a 2-gang pot; it might eliminate the need for a caps-switch.

[strungout]

Paul: Good idea. So, I would just turn that other 10k into a 2k2 leading into the 2nd part of the dual-gang pot, then? Having just a knob to turn will eliminate the need for a switch. That's good. Less clutter.

[strungout]

Well, I tried a dual-gang pot and it works really well! Gained a bit more fast and a bit more slow. More gangs would be even better. I found a 3-gang , at mouser, I think, but not in 25k version. I could just put 120k resistors across each set of outer lugs... It'll have to wait til I have some more stuff to order XD In the meantime, I can use a switch along with the pot Stephen (duck) showed me some stuff for switching options/ideas. Together, they will give me a wide range of speed. At least compared to the original.

Right now, I'm also trying to do some nice graphics for the box. Tried t-shirt transfer but it wouldn't sfully stick. Bought some clear sticker paper. Should be simpler, ha. Anyway, I'll post pics when I'm done.

Thanks again for the help, guys!