Add depth control to Smoothie?

[sjaustin]

Not in a 1590a enclosure. Is this just a matter of using a pot in place of one of the resistors, or would it be more complicated than that?

[Stomptown]

It is actually a 20k pot in place of two 10k resistors that run in series. When the pot is at 12 o'clock You have a stock smoothie. When you deviate the ratio of dry to wet signal is changed. If you are in the USA you will find it extremely difficult to find a B20k pot and will most likely have to resort to a B25K. It works fine as well.

In the smoothie you will need to replace r15 and R16 with the pot. Connect lug 3 of the pot to the R16 pad that is electrically connected to pin1 of IC2. Connect lug 2 on the pot to the R15 pad that is electrically connected to C6. Connect lug 1 of the pot to the R15 Pad electrically connected to pin 1 of IC1. Done!

FYI the phasing gets very subtle very quickly when you deviate from 12 o'clock in either direction. When you approach min or max all phasing is gone. This makes sense since the you are essentially eliminating either the wet or dry signal ...

[sjaustin]

Thanks for the reply, Stomptown. The mechanics of the mod make sense to me, but I'm not clear on what happens if 12 o'clock is "unity" depth. Is there any sonic difference between turning it one way vs. the other?

[Stomptown]

There is a sonic difference, but the phasing is so subtle in either direction and the sonic difference is... well... Subtle!  Basically you get more wet signal in one direction and more unaffected dry signal in the other.  If you want my opinion, I prefer the phase 45 stock and don't have the mod on my phase 45 build. It is really a personal preference. for the most part I prefer simplicity over bells and whistles. That being said, I have sold a bunch of PCBs with the mod included and people seem to like it for the added versatility. If you go with it and find that you agree with me you can always just keep that know at 12 o'clock

[sjaustin]

Cool, thanks for your help. I have a stock build, and it's really quite nice as it is. Honestly, the only reason I am considering a depth knob is because I am considering a 3-in-1 modulation build, and the knob placement is wonky with the phaser having only one knob. 

[ddog]

There is a sonic difference, but the phasing is so subtle in either direction and the sonic difference is... well... Subtle!  Basically you get more wet signal in one direction and more unaffected dry signal in the other.  If you want my opinion, I prefer the phase 45 stock and don't have the mod on my phase 45 build. It is really a personal preference. for the most part I prefer simplicity over bells and whistles. That being said, I have sold a bunch of PCBs with the mod included and people seem to like it for the added versatility. If you go with it and find that you agree with me you can always just keep that know at 12 o'clock

Is it possible to remove that depth mod from your PCB? Maybe solder a resistor instead of Pot? I find it hard to find the right settings to bias the phaser

[Stomptown]

Yes! You would just remove the blend (depth) pot and solder one 10K resistor between pad 1 and 2 and solder another 10k resistor between pad 2 and 3. This will do the same as having the B20K pot at 12 o'clock. If you have 1/8 watt resistors, those should fit perfectly lying down.

Jon