4 position Q-Switch

[jazzyvee]

Thanks Mica & Ron kindly for this contribution. My electronics knowledge and dexterity with a soldering iron is definitely not sufficient to fully understand and carry out a modification of this complexity with any degree of confidence. I’d definitely end up with a lovely piece of burl redwood silent alembic wall art.

[flavofive]

Thank you Mica, and thanks to Ron!  Interesting information, especially about the Q "trimming".  Very cool!  I also wasn't aware that a break-before-make switch (for the Q control) could cause a pop/chirp - glad Alembic designed the Series 1s to avoid this!

[BeenDown139]

that explanation is a flashback to my analog filters class back in engineering school in the mid-70's

whooo00OO00oooo!

🗿🐕

[JimmyJ]

Wow, amazing description of the circuit by the designer himself. Thanks Ron and Mica.

My problem is that whenever I listen to Ron describe something in detail I get about three sentences in and my eyes glaze over and my brain freezes up. My next question is usually something like “what day is it again?” 

I should know this… but when Ron describes fine tuning the “Q” is he talking about the center frequency of the boost, the slope or shape of the peak, or the amplitude gain? 

In the end Jazzy it seems that he concurs with your idea of using one of our Grayhill pickup selector switches as a 4-position Q-switch. You may have inspired a new option!

Great stuff!
Jimmy J

[edwardofhuncote]

What my wire-dunce pea-brain got out of the whole post was that even the blamed switches in an Alembic are spec'd so they don't pop when you use them. Soooo... a thousand thanks for something I knew but hadn't realized was on purpose.

[jazzyvee]

It's good to know that it's possible to do this, even if it's not a practical easy DIY build option. If it was it would be good to have the first one. In practice the tone i'm looking for would be achieved with the mod just on the neck pickup and if I was able to get the mod done it would make sense to have both Q's changed to use the same type of switch but with with the 4 position mod on neck and 3 position or CVQ on the bridge. So I can quickly switch the neck to that tone and back for a phrase or melody which is a lot easier than using a CVQ. Might have to contact John East to see if he could do the mod based on Ron's input.