Adding a Dry Out to the AD3208?

[ppatchmods]

I searched and didn't find too much on the subject. Is there an easy way to do it like on the rebote? thanks

[Mark Hammer]

If you want a dry out that only comes into effect when two plugs are inserted to the output jacks, that is a little more complicated.  But if you want a dry out that is always split from the wet signal, then it is as simple as lifting the end of the 24k dry mixing resistor at pin 2 and redirecting it to a 1uf cap and 100k to ground soldered to another jack.  You now have the dry at one output and the wet at the other.

As noted, if you want to have a mono wet+dry mix as the default, and the option of separate wet/dry outputs, you need to either use a SPDT toggle to break the connection at pin 2 and redirect the dry to the alternate output jack, or else use a more complex switching jack that willdo the redirecting for you.  They aren't particularly compact, though.  Toggle is likely simpler and less error-prone.

[ppatchmods]

thanks mark. i was hoping it would be a simple add on. i would really like it to be switchable because 2 amps are heavier than one! i'll keep rolling it around in my noggin until i wrap my head around it.

[ppatchmods]

Mark. i was thinking that i read somewhere that people have used a switchcraft jack with an extra ground pin to ground it out when it isn't being used. would that work for the dry out in this case?

[Mark Hammer]

There ARE various exotic switching jacks that will make interesting sorts of connections for you when somethng is inserted.  You can often find these in older stereos and tape/cassette decks, especially as headphone jacks.

What is peculiar about these jacks is that, unlike a more familiar closed-circuit jack where two lugs are in electrical contact unless a plug is inserted and simultaneously makes contact with one and nudges it out of contact with the other lug, these have built-in "leaf" switches, similar to a Gibson LP/SG pickup toggle that moves a common contact between two alternates.  In the diagram here, D is a schematic depiction of a more standard stereo closed circuit jack, which I am sure many have used  as their input jack on stompboxes, simply because they couldn't find a sipler one like B.  Diagram C, however, shows you a switching jack using a "leaf" system where plug insertion forces a moveable leaf to switch from one contact to another.  That long triangle shown in the diagram is plastic, such that it never makes electrical contact with the plug, only physical contact.  Inserting the plug essentially actuates a physical switch.  A jack like this would make it possible for you to send the dry signal to this alternate jack, and have it routed back to the op-amp mixer stage for combination with wet, if nothing is inserted into the jack, or have it fed as a separate out, and be lifted from the mixing stage, when both jacks are used.

[ppatchmods]

thanks so much Mark! It makes more sense now and I can see how it would be really large.

[ppatchmods]

the only place i could find a spdt switching jack was ebay for 20$!! ouch! anyone know of another source?

[Mark Hammer]

This one will do exactly what you need/want.  A whole lot cheaper than $20.

http://www.smallbearelec.com/Detail.bok?no=724

[ppatchmods]

thanks. already have a list of stuff in my cart from smallbear!

[ppatchmods]

i purchased the switching jack for this long time delay project...i'm not sure how to wire it. could anyone point me to a diagram. it is the one linked to a few posts back. just trying to add a dry out to this delay. thanks

[ppatchmods]

bump

[ppatchmods]

can anyone help me out with this? my jack has the pins labeled like this. i want to wire it so the dry output is only active when i insert the plug. i have the theory in my head but i've never wired a jack like this. it should go (i think): lift the 10k (originally a 22k) from pin 2 of the tl072 and take it to a 1uf cap (NP?) to a 100k to ground. then on the other side if the switching jack, wire it back to pin 2 of the tl072??     not sure where to make the connections or if that's even right...

[ppatchmods]

can anyone help me out with this? my jack has the pins labeled like this. i want to wire it so the dry output is only active when i insert the plug. i have the theory in my head but i've never wired a jack like this. it should go (i think): lift the 10k (originally a 22k) from pin 2 of the tl072 and take it to a 1uf cap (NP?) to a 100k to ground. then on the other side if the switching jack, wire it back to pin 2 of the tl072??     not sure where to make the connections or if that's even right...

i think i figured it out: take the 10k lifted from pin 2 to lug 1 of the jack. wire lug 3 with a 10k to pin 1 of the tl072 and lug 4 back to pin 2?

[ppatchmods]

Sorry to keep beating a dead horse, but I still have a few questions about this.
1. Why is the extra filtering necessary when you break the connection @ pin2 to take it to the jack?
2. If I run this to a switching jack, will the dry output cut out when the pedal is bypassed? I am taking the connection from the buffer which will be bypassed when the pedal is off.
3. Still a little unsure on how to wire the jack.  Any thoughts? Thanks

[PRR]

I don't know what a "AD3208" is, or what you are trying to do with/to it.

If you are just hung-up on how the jack works, this is what happens: