Need help on my first DIY ! (Phaser Kit)

[thermionix]

Long for delay, steel for reverb.

[buisson]

Hi Mark,
I'd like to go on your tips about making it better.

I have a question about that part :

Finally, all phasers are capable of producing vibrato if one cancels the clean signal.  When clean and phase shift are combined, tat produces the phasing effect, but when clean is omitted, you will hear a pleasing pitch change.  To produce this, simply desolder one end of R18, and install a toggle to reconnect it.

What kind of toggle should I use ? (je suis un gros débutant !  )

Merci !

[Mark Hammer]

Même les débutants peuvent faire cette modification!

On a bésoin du deux contactes, seulement: un toggle SPST.

Commercial phasers that use electronic switching usually "cancel" the effect by simply turning off a FET between the phase-shift signal and the point where phase-shift and clean are mixed.  This means they cannot produce vibrato.  Si on annule le piste "clean" ET le piste "phase-shift", on a rien.

So, if you are using true bypass switching, you have the option of lifting/cancelling the clean, en même de retenir le "phase-shift".  Et ça produit l'éffet vibrato.

Veuillez noter que l'éffet vibrato est imperceptible sauf que le vitesse est medium ou vite.

[buisson]

R27 (3m9) sets how wide the sweep is.  Some issues of the Phase 90 used 3m3 and those will sweep wider, by going even higher.  Usually, modulation effects, like phaser, chorus, tremolo, and flanger will include a sweep width control (usually called "Depth") that sets how wide the sweep is.  The way that human hearing works, we prefer shallow/narrow sweep when the speed is fast, and wide sweep when the speed is slow.  As with feedback, MXR picked a compromise value for R27, that would work acceptably for all speeds.  But it can be changed to produce better effects.  3m0 or 2m7 is probably as low a value as you want to make it, and values above 4m7 will not produce much that is useful.  So, if you can find a 2meg potentiometer, putting it in series with a 2m7 resistor, and using that in place of R27 will provide nice variation in sweep width.

I tried this Mod.... A little boost, but no more Phaser effect... :/
Maybe I do it wrong : Coming from the 2m7 (from R27), going thru the Pot (right leg from front view) going back to the PCB from the Middle leg of the Pot (and switched back). Left leg to the Ground... Nothing.

(PS : its a Linear Pot)

[Mark Hammer]

If you put 22M in parallel with 3M9, you have 3M3.  If you put 15M in parallel, you get 3M1.  Put the 3M9 back, and add other resistor values in parallel by soldering them to the copper pads on the board.