TIME-SPACE: New dual delay design!

[Morocotopo]

Here I present you my latest creation/abomination/pedal thing (drum roll):

TIME-SPACE!!!! (Ver 1.0)

Time-space is a dual delay, using two PT2399 chips as the core of the effect. This came about from a desire to combine the best features of all the PT2399 delays available for building, of wich I must say I have built most. Essentially an ambient machine.

Main features:
-  Two independent delay lines with a full set of controls each, that can be set to work in parallel or series, allowing for a variety of delay and ambience sounds.
- An LFO for modulation, assignable to either of the delay lines or none.
- A crossfeedback control (only available in parallel mode).
- Buffered FET bypass.
- A dry out and wet only switch, that together allow to route the dry and wet signal to different amps, mixer channels, etc.

Acknowledgments:
   This project was inspired by many previous works such as the Rebote 2.5 by Francisco Peña (Tonepad), the Echo Base by Ian M. (Slacker at the DIYstompboxes forum), the PT-80 by Scott Swartz, the Ping Pong Delay by the people at Buildyourownclone.com, the Small Time by The Valve Wizard (Merlin Blencowe), and many others that generously contributed their projects, mainly at DIYstompboxes.com. To all of them, thanks!

Controls:
Time1:             Controls the delay time for the delay line 1.
Feedback1:       Controls the number of repetitions of the delay line 1.
Level1:             Controls the volume of the delay line 1.
Time2:             Controls the delay time for the delay line 2.
Feedback2:       Controls the number of repetitions of the delay line 2.
Level2:             Controls the volume of the delay line 2.
Crossfeedback: Controls the amount of signal sent from the delay line 2 output back to the delay line 1 input. Operational only in parallel mode.
LFO 1-OFF-2:    Controls wich delay line is affected by the LFO´s modulation, or turns it off.
Speed:             Controls the modulation LFO speed.
Depth:             Controls the amount of modulation LFO sent to the delay line selected.
Wet only:         When activated, the out jack gets the processed signal only.
Parallel/Series:  This switch toggles between parallel or serial delay lines.

Other operational characteristics:
The Dry Out jack gets the dry signal at all times.
The Out jack gets either the mix of dry and wet signals when the effect is on, the wet signal only if the wet only switch is activated, or the dry signal if the effect is off.
In series mode, the feedback 1-2 and the level 1-2 controls are in, well, series, so the final amount of feedback / level is set with all four controls. It´s possible to make it oscillate/feedback in this mode, so be cautious in setting the controls. Also, in this mode, if one of the level controls is fully off, you won´t get any delay, they both have to be used for the final level.
In series mode, the Crossfeedback control is deactivated to avoid excessive feedback/oscillation.
There´s an internal jumper that allows to set the operation of the effect either with or without tails when bypassed. That could be made an external switch if you wish.
This is NOT true bypass, so as to be able to have tails. There´s no obvious tone degradation in bypass to my ears.

Quirks/Things to improve in Ver 1.1:
- When switching from parallel to series, you get a nice loud ¡POP!, so don´t do it while the effect is on! I believe solving this would make the circuit much more complicated... possibly using FET´s to switch more slowly (that would require, I think, six more of them!)? LDR´s? Since the 3PDT that switches doesn´t have DC on any leg, I believe the problem is the discontinuity in the waveform itself when switching that makes the pop. Anyone can correct/confirm?
- Some control pots could be replaced by log/antilog to get a better feel. Untested.
- The modulation depth is dependent on the time pot(s) setting, the higher the time the deeper the modulation. It would be really nice to have modulation that changes the same amount of pitch or perceived pitch regardless of the time pot setting. I believe this has to do with the percentage of the LFO voltage swing versus the static voltage of pin 6 in the 2399 chips, but it´s not really clear to me. I noticed the same behaviour in my Echo Base. Does any expert have a suggestion on how to solve this?
- I just finished making it,now comes the real "in use" testing. I have the feeling that some controls could be eliminated or simplified, but the idea was to first make it with all the bells and whistles, and then if anything proves to be superfluous, do away with it.

Build notes:
   I would classify this project as advanced. I made the smallest PCB that I could, to fit it into a BB size box, so the PCB is quite cramped, requiring good soldering technique to avoid solder bridges. Most resistors are "standing up" to save space, most polarized caps are tantalums to the same effect, and all non polarized caps are ceramic multilayer ones. Check the size of all caps on the layout before ordering: some ceramics use two holes spacing, some three holes spacing. This was not designed to take poly caps, although in some places those blue box ones could fit instead of the ceramics. But the main issue is the wiring. The PCB is NOT designed for board mounted controls. With four switches, three jacks, two LED´s and nine pots, the wiring is quite complex! Something like 40/45 wires... you have been warned. It was quite a job getting all this stuff inside the box.
Power consumption is around 40 mA when on, so I´m not sure how much a battery would last.

Well, that´s about it for the formalities. Now, the files.

Pics:

Loaded PCB:



This is gonna be complicated...



Oh lord, help me!



Completed:





The build files, just in case somebody feels brave enough...

http://www.aronnelson.com/gallery/main.php/v/Morocotopo/TIME-SPACE+1_0.zip.html

A coulpe of audio demos, fairly disorganized. I just jammed a bit with different settings and then edited the most representative bits of the sound of the thing. Always levels at max to hear clearly the FX, in use one would be more subtle. Not many "normal" delay sounds. Guitar into PC with a clean amp sim.‏ First  in series mode and then in parallel.

http://www.aronnelson.com/gallery/main.php/v/Morocotopo/Series+w_amp+sim.mp3.html

http://www.aronnelson.com/gallery/main.php/v/Morocotopo/Parallel+w_amp+sim.mp3.html

Well, not much else to say. I quite like the sort of ambient sounds it makes, I believe it´s a successful build. Took me quite some experimentation time to arrive at the final schem.

Hope it´s of interest,´cause I spent quite some time typing!

[Maik]

Please put it into dropbox or something else. Can´t download it (file is damaged it says)

[akc1973]

Sounds, great! Excellent Work!!!!!!!!! 

[Morocotopo]

Akc, thanks.
Maik, I tried downloading the file and it works fine. Maybe try again?

[haveyouseenhim]

I got the download to work. I just dont have a program to view the BOM. and the last thing I need is another program to slow my joke of a computer down.

Would you post the BOM here?

[defaced]

docx is the "new" Microsoft Word document file type that started with with Word 2007.  You can download the compatibility installer from Microsoft that will allow earlier versions of word to open the docx files. 
http://www.microsoft.com/en-us/download/details.aspx?id=3

[haveyouseenhim]

Well that didn't work....     When i click it now it asks if i want to save it    I can't figure it out

[Morocotopo]

Mike, give me a little time and I´ll upload the BOM in a pdf or tiff, so you can open it.

[Maik]

 

[slacker]

Looks and sounds great. Nice work on the schematic, for something that complicated it's very easy to understand.

[Morocotopo]

Mike, here´s the BOM in a pdf:

http://www.aronnelson.com/gallery/main.php/v/Morocotopo/TIME-SPACE+1_0+Bill+of+Materials.pdf.html

Ian,thanks! I think of this thing as a sort of an overdeveloped Echo Base. So it´s partly your fault!



I certainly tried to make the schem as clear as possible, to be able to understand it as clearly as possible myself (does that make sense? Hmm.)

EDIT: By the way, anyone has any suggestions on how to solve the two issues I mentioned, that is, the popping when switching from serial to parallel and the LFO depth dependency on the time pots settings?

[Mark Hammer]

VERY nice.

[haveyouseenhim]

Awesome. Thanks Ariel

Looks like I'm going to have to stock up on multilayer ceramics

[Maik]

Could somebody put it on dropbox?
When downloading it says "file corupt"

[deadastronaut]

@maik:  sure here ya go

https://dl.dropbox.com/u/7464107/main.pdf


looks like a nice project!!..cool.

[Maik]

Thanks Rob.
But I need the rest also (layout,pcb,ect)

[Morocotopo]

OK, did a little revision on this. Just in case someone is going to build it (unlikely it seems, the wiring must have scared everybody away!!): the mod depth range was a bit low, only noticeable in the last third of the delay range, so I made R30 a 330K. Now I get modulation earlier in the time pot range. It´s a balancing act: if R30 is too small, you get too much modulation at max delay,even with the depth pot at minimum, if R30 is too big, you don´t get modulation in the shortest delay range, even with the delay pot maxed. Try from 220K to 470 for R30. Another option would be to try a 250K pot for the depth one, to get more range,that would surely require to change R30 to a suitable value. Í´m NOT going to dissasemble the friggin´ thing to change the pot, that would require a full dissasembly since the pots are under the PCB. No way! finished job for me.

If anyone ever makes this, I´d like to hear from you! Always nice to hear from someone who enjoys destroying their eyesight fiddling with lots of little wires just like me. 

[mph]

Congrats for the work!
but I've also a problem while downloading the files, please could you post another link?

Thanks a lot; I would love to modify it to fit a modular system 

[Maik]

Could someone please post the layout, pcb ect on another link?

[Morocotopo]

Listen guys, those who want the docs write me a PM with your e-mail and I´ll send them to you. I don´t have a file host account, and also I don´t want to post this schem all over the net. Actually I´ll take the files down from the gallery. So write me!

Cheers