cool reverb apart from switch spdt 'pop' issue

[slacker]

Small caveat with that idea for anyone who's interested is that in "tails" mode and bypassed the drymix and volume controls will set the level of the bypassed signal. The volume control probably won't be much of a problem if you're just using it to balance the level compared to the true bypassed level but it's possible to set drymix to 100% wet leading to no bypassed signal. Might be fine depending on how you use the reverb.
It really needs some way to bypass the drymix pot when bypassed, I'm thinking you can just lift the end that goes to Vb or better switch a large resistance in there so that the pot is effectively turned all the way up when bypassed. I can see a way to do this using just the existing 3PDT, but it means losing the LED, unless there a way to rewire it to keep the true bypass/tails option and use millenium bypass for the LED?
Otherwise it's electronic switching time.

[deadastronaut]

i don't want to lose my beloved led


hmmm electronic switching?...

[bluebunny]

Since you have kind of a buffered in and out anyway, you could just stick a FET in the path from the input buffer to the brick and switch that?  Like, fer example, Merlin's "Small Time" delay?  And you get to keep your LED!!   

[deadastronaut]

hi marc: care to edit my schemo with that idea?...then i'll bread it up and try it...cheers man.

[bluebunny]

PMed...  (no access to FTP from work...)

[deadastronaut]

from marc, ^ got it...here ya go.



so this would be buffer bypass, with tails?...but not true bypass too?..

i'm looking at having a tails on/off toggle...but a 3pdt TB too..

[bluebunny]

so this would be buffer bypass, with tails?...but not true bypass too?..

Er, yes.      After all that effort...      

Or you go the whole CMOS-switching route.  Lots of handy hints at Geofex.  I'll leave that one to you, Rob!

And I'm *not* skiving.  I'm on a "coffee break".   

[deadastronaut]

lol...i'll give it a go man,  thanks for that .

[slacker]

You can add Merlin's tails/TB switching to Marc's thing basically the same as for my idea. Still leaves you with the drymix issue, a second fet could take care of that.

[samhay]

^Still leaves you with the drymix issue, a second fet could take care of that.

IC2d is a diff amp, so as I read it, the reverb pot does not affect the dry level, but just mixes in the wet - I might be wrong though (again).
The volume pot will be in the circuit. Merlin got round this in the Small Time by leaving the dry level at unity gain, and by omitting a volume pot.

[deadastronaut]

@sam: yep reverb level adds the wet....i will be adding an overall vol pot on the out.

@ian: another fet?..

[slacker]

@Sam you're right the reverb level doesn't affect the dry signal. Actually it does a bit but not enough to worry about, it plays a part in setting the gain for the non-inverting side.
The schematic Rob sent me is different to the one Marc posted though and also has a volume control for the dry signal, see my hacked schematic a few posts back.

[samhay]

^The schematic Rob sent me is different to the one Marc posted

Gotcha. In that case, a second FET switch between the dry mix lug 1 and Vref would do the trick wouldn't it?

[slacker]

Yeah, I think so.

[deadastronaut]

oops!...sorry guys, cross schemo's..  

can we go with the schemo marc posted...as that is the one i have my verified pcb layout  for...and intend to tweak/re jig....

[samhay]

That would make things a little easier. Do you want a true bypass option? It is do-able - I set up my Small Time delay like this...

[deadastronaut]

That would make things a little easier. Do you want a true bypass option?

cool..yes please!..

[slacker]

Transplant my mods into that schemo, tweak the dry side for unity gain, job done

[deadastronaut]

Transplant those. 2 resistors and switching from the schemo a few posts back..?...thats it?

[samhay]

If you want to use the FET switch, then I think this will work.
The 3PDT is the foot switch and the DPDT a tails toggle switch.