So I have two Phaseur Fleur (Commonsound/4MS) circuits in this box. I built this many years ago, and have it wired so that the first one can be run on its own. If I click on the second one, it adds it in parallel and combines the signal.
There is no additional circuitry when running in parallel. When run in parallel, it is just two passive Y-splits. One in the beginning to feed both effects and one at the end to combine them. Honestly, it sounds exactly as I envisioned... I can hear both phasers working and they mix together in an interesting way.
I know running effects in parallel may not always work well, and it is typical to insert a mixing circuit at the end. But in a case like this, where both effects are the same effect, so input/outputs to the effects are the same, is there much to be gained by exploring different ways to combine the signals? I am guessing a lot of the special considerations with regard to running parallel effects is because it is going into different effects chains before combining, which is not the case here.
Here is the pedal in question:
(https://i.postimg.cc/VS0zJGgs/phaseur-fleur.jpg) (https://postimg.cc/VS0zJGgs)
Any ideas/thoughts are appreciated!
Both inputs and outputs are buffered (BJTs) so your mixing scheme is fine. You did good.
The Mutron Biphase puts two 6 stage phasers in series.
The other line to think about is linking the two LFOs. One control both/ in or out of phase. Mix two LFOs to make a single phaser more complex, etc.
Consider series, like this. Can produce some interesting phenomena, especially when the LFOs are unsynced and running at different speeds.
Cool pedal.
Quote from: idy on September 22, 2022, 01:14:46 PM
Both inputs and outputs are buffered (BJTs) so your mixing scheme is fine.
Is that because current is limited through R22?
http://commonsound.org/phaseur/pcb1.1f/schematic.pdf (http://commonsound.org/phaseur/pcb1.1f/schematic.pdf)
Quote
Is that because current is limited through R22?
I see the second BJT is not an emitter follower buffer but a collector follower mixer/amplifier. Still provides isolation.
Quote from: idy on September 22, 2022, 01:14:46 PM
Both inputs and outputs are buffered (BJTs) so your mixing scheme is fine. You did good.
The Mutron Biphase puts two 6 stage phasers in series.
The other line to think about is linking the two LFOs. One control both/ in or out of phase. Mix two LFOs to make a single phaser more complex, etc.
Thanks! Glad to know it's setup in a reasonable fashion at the moment. I haven't gotten into more complex ways to put them together, but the idea of linking the LFO's is a great idea.
Quote from: Mark Hammer on September 22, 2022, 02:40:25 PM
Consider series, like this. Can produce some interesting phenomena, especially when the LFOs are unsynced and running at different speeds.
Cool video, thanks for sharing!
This is definitely being considered. Sometimes, I wish to use the two phasers separately, due to having different settings that would sound good when used alone. But the second one only comes on when used in parallel with the first, so it never gets a chance to be used by itself. If I run it in series, I get the cool effect of two phasers in series, plus easier to run them separately as needed.
Quote from: idy on September 22, 2022, 03:53:19 PM
the second BJT is not an emitter follower buffer but a collector follower
Interesting enough.. :icon_wink:
So you invented a single stage non-inverting CE amp..
There are several different versions of "in series". One is two complete phasers, that each combine phase-shifted and dry signal, such that there are two intact circuits, each producing 3 notches. That, in turn has two different subforms, like I illustrated in my video: one using a common LFO, and one using two independent unsynced LFOs. The second form of "in series" would be one in which the first set of 6 phase-shift stages are placed in series with the second set (12 stages in all), and THEN combined with the dry signal, for 6 notches.
Personally, I've come to view 6 stages as the sweet spot for guitar phasers. Much more than that (okay, so MAYBE 8 is fine) and the notches become situated outside the frequency range of normal guitar signal. I mean, it will sound "different", because the notches you can hear are moved over in the spectrum, but it won't sound like more notches. It will be good for keyboards, and other instruments that have broad bandwidth, but not especially inspiring for guitar; at least no moreso than 6 stages. But that's my view and not gospel of any sort.
Quote from: Processaurus on September 22, 2022, 03:29:16 PMIs that because current is limited through R22?
http://commonsound.org/phaseur/pcb1.1f/schematic.pdf (http://commonsound.org/phaseur/pcb1.1f/schematic.pdf)
Yes.
A perfectionist would add a low value (1k or so) mixing pot to counteract possible R23s // R22s // Q2s Collector internal impedance dissimilarities..