AD-3208 build report

[idiot savant]

well, i finally finished,  i used MN3205's  and damn it sounds sweet!

i added, well, alot...i started with commonsound's lfo
http://www.commonsound.com/tremulus/auxlfo_modulate.pdf
and wired it up according to a post by RickL(thanks!) i did change the range pot to 500k for a better range without eating up delay time, it goes from a good wow and flutter kind of wobble, to a neat chorus type sound to full out detuned wackyness. i found that i had the best range with a "easyvibe" ldr in the LFO

i also added the pt-80 FX loop that moosapotamus drew up, and i was having the hardest time with it. i kept getting a pop when switching the stompbox in the loop in and out. i fixed the problem with two 10uf electro caps just before the opamp stages.

this is the messiest build i have ever had, and i added alot to it during construction, so the thing is really ugly as you can see :lol:
my fav so far has been trem, and phase in the loop, fuzz is fun too, and so is an envelope filter. great sounding delay, this is one i set out to build right from the start, and im really happy with it,

thanks go to Scott Swartz, Moosapotamus, RickL, and everyone here who helped me or has given me advice!!!

[Mark Hammer]

There are butts and there are butts, an I find that one kind of cute rather than ugly.  Those D-size chassis are sweet, ain't they?

Given the available space, here's a suggestion that is easy to implement.  Every once in a while, you encounter a situation where you want to hear the "tail" of an echo, but you don't want to add anything new to the delay path while hearing that tail.  The solution here is to lift the input to pin 11 of the 570/571 compander chip.  The path from point A to the mixer stage will remain intact, permitting you to here what you are currently playing, and the recirculation path remains intact, permitting any echoes to continue until completely decayed.  All that changes is that nothing new is added.

The key is to get two switches: one a SPST toggle to re-establish that link, and the other a momentary SPST normally-open footswitch to temporarily feed pin 11.  This will let you temporarily feed the delay-line as long as you press on the momentary switch, and instantly kill input the second you lift your foot off.  The toggle permits restoration of normal functioning.

Try it, you'll like it.

[RedHouse]

What chassis is that?

[idiot savant]

thanks mark i want to try that one, i think bigtonemusic did that very same thing to his Build your own clone delay thingy

look here:
http://acapella.harmony-central.com/forums/showthread.php?s=44f34c331102c57b5b7fec9fa19493a4&threadid=949825&highlight=bigtonemusic

[RedHouse]

What chassis is that?

Hello?

[d@vide]

hammond 1590 D

[searoad]

sorry to bump the old topic..
recently i want to mod my rebot2 delay.
(i have the memoryman so dont wanna go adding the lfo mod.)
the "echo tail/hold sampler" mod looks interesting!
my question is that  both Mark and Byoc man suggest using 2 switches on this.
but can i use a normally-close momentary footswitch(dont know if there is one)
then i can step on it to get the echo tail immediately?
or 2 switch are needed to get rid of something?

another question is if i want to add this and the FX loop using moosapotamus's sketch.
(http://moosapotamus.net/THINGS/pt80delay.htm)
as both two work on the same place, what is the order to build?
"echo tail" to "FX loop" or "FX loop" to "echo tail"?
thanks!!

[Mark Hammer]

For the Rebote 2 (NOT the 2.5), you would cut the trace shown here: http://img.photobucket.com/albums/v474/mhammer/TRAILS.png

This severs the connection between the audio input and the PT2399, but NOT the path of the regenerated signal, nor the path of the audio input to the mixer stage.  So, if you had a normally closed momentary switch that completed the connection interrupted by cutting the trace shown, stepping on the switch would cut any additional input to the delay chip, and permit only that which is already passing through the PT2399 (for the first or Nth time) to find its way to the mixing stage.  The moment you lifted your foot up from that switch. all audio input wold resume being processed by the delay chip again.

Near as I can tell, it ought to be pop free, but we'll let empirical evidence determine that.

The ideal is to have a momentary switch that can be configured as NC *or* NO, and a toggle that switches between those two possibilities.  For instance, sometimes you want to leave the delay on and temporarily "declutter" by preventing additional content from being repeated.  Other times you want to essentially leave the delay off and temporarily insert a note or riff for repeat purposes, which then continues for a bit without adding anything new.  The normally closed type switch would do the first one, and the normally open type would do the second.

[searoad]

thx first!! and just for reconfirmation..
for NC footswitch it will sound like: ("D" is the note i play, while "d" is the delay sound.)
Ddd(acts as normal)->(step on it)-> ddd(and i cant add any note) ->(closed again) ->Ddd(back to normal.)
for NO case: DDD(no delay) -> Ddd(acts as normal) -> ddd(cant add any note.)
is that right?
then combine with toggle and effectbypass switches i can get both two possibilities? (maybe cause pops..)

http://buildyourownclone.com/samplemod.JPG
byoc man's idea about this. the 1uf cap he lifted is which under the arrow in your pic.
since it looks safer than cutting trace. can i do that too? (not sure if they are same circuit.) or lift 15k will do so?
thx again!!

[Mark Hammer]

thx first!! and just for reconfirmation..
for NC footswitch it will sound like: ("D" is the note i play, while "d" is the delay sound.)
Ddd(acts as normal)->(step on it)-> ddd(and i cant add any note) ->(closed again) ->Ddd(back to normal.)
for NO case: DDD(no delay) -> Ddd(acts as normal) -> ddd(cant add any note.)
is that right?

Yes, it is.  Weird-looking, but correct.

then combine with toggle and effectbypass switches i can get both two possibilities? (maybe cause pops..)

Yes.  The toggle selects which of the two modes the momentary works in.  Smallbear sells a momentary DPDT (http://www.smallbearelec.com/Categories.bok?category=Switches) which can be wired up as NO or NC (http://www.smallbearelec.com/Detail.bok?no=27).  That may be the ticket.

http://buildyourownclone.com/samplemod.JPG
byoc man's idea about this. the 1uf cap he lifted is which under the arrow in your pic.
since it looks safer than cutting trace. can i do that too? (not sure if they are same circuit.) or lift 15k will do so?

That scheme will work but is destined to pop.

thx again!!

You're welcome.

[searoad]

i wired it yesterday and finally understood why you recommended a NO type switch.
setting the toggle off for a NC switch is useless,
the echo decay from a normal delay is nothing special, and even decay faster.
will buy a normal-OPEN switch and try again!

[Mark Hammer]

Sorry that didn't work out for you.  I think they are both useful mods, though the NO is perhaps the more useful for more people.  It would be the one that lets you add delay for select passages when you want it.  For instance, you work your way through a frenetic solo up to one screaming note way up high on your E string that you want to hold and make sound even more dramatic.  So, at the moment you hit that note, you step on the momentary switch and the note suddenly gets repeated.  You take your foot off the momentary and the rest of the solo or rhythm playing continues with some fading memories of that "dramatic" note.  That's instant Jimmy Page, my friend.