Hi all,
I'm thinking of my next project. What I want to do is build a double delay pedal. Here's a plan of what I've come up with;
(http://www.airraid.info/kbdir/dbldelay.gif)
My plan is to build it around the rebote 2.5 delay and to primarily run it off a 9v adapter as I doubt battery would last all that long. In addition I want to have two LED's that blink on the repeats of both delay phases so I can visually check the timing.
Firstly, I would like to ask if anybody would think this is a worthwhile project to build? Also, does anything stand out in my plan that may prove problematic?
going for the brian may delay?
i think its already been done. there are cheap mass produced delays with a "brian may" or "queen" setting.
cheers
ulysses
I Didn't have Brian May in mind with the project. I basically want to build a delay that will have a few creative options hence the double delay. I wanted the different outputs as options for different amps/fx chains etc and possibly build a signal mixer for my pedal board so I can mould my signal again. I just basically wanted to know if this is a good way of doing it and/or if there may be problems on the way...
I did come across the Digitech Brian May pedal but that's not what I am after, I am after my own sound and delay is a big part of it, hence a speacial delay box.
Thanks
Are you going to have some way to switch delays aside from the outputs? Instinctively, if I was going for maximum flexibility, I'd want some way to choose 1/2/Mix/Bypass with switches.
I believe the rebote circuit already has a buffer in it (to feed the dry and delay lines0. So if you were planning on just using the layout from tonepad and throwing two of those boards in a box, you can probably tap the clean signal off of one of those, and use it for your dry tap, and to feed the other delay, and save making a separate buffer.
I would also think about the option of being able to chain the delays, (series instead of parallel) that can be a fun sound as well. I've certainly gotten some fun sounds chaining one rebote into another.
i was plannig on trying it but with just 2 delays in series... one set for a slapback and the other for long delay, first one in mono second in stereo (dry/wet) but i guess playing with both setting can make pretty cool sounds...
R.
Quote from: Antero on March 25, 2007, 09:41:03 PM
Are you going to have some way to switch delays aside from the outputs? Instinctively, if I was going for maximum flexibility, I'd want some way to choose 1/2/Mix/Bypass with switches.
I suppose this could be done but I had in mind using different output jacks for Delay 1, 2 and mix so they could go to different amps. Maybe I could design it so the mix output is switchable.
Quote from: sfr on March 25, 2007, 10:28:29 PM
I believe the rebote circuit already has a buffer in it (to feed the dry and delay lines0. So if you were planning on just using the layout from tonepad and throwing two of those boards in a box, you can probably tap the clean signal off of one of those, and use it for your dry tap, and to feed the other delay, and save making a separate buffer.
Ah thanks for pointing that out, I haven't taken a good look at the circuit yet so I'll keep that in mind when I'm ready to go further into it.
Quote from: sfr on March 25, 2007, 10:28:29 PM
I would also think about the option of being able to chain the delays, (series instead of parallel) that can be a fun sound as well. I've certainly gotten some fun sounds chaining one rebote into another.
I guess this could be switchable. The only thing I was thinking about this was maybe it would be too noisy?
Quote from: blanik on March 25, 2007, 11:33:08 PM
i was plannig on trying it but with just 2 delays in series... one set for a slapback and the other for long delay
That's exactly one of the ways how I want to use it. I think you can get some pretty good sounds with double delay.
fresh for Frankfurt:
(http://img.photobucket.com/albums/v437/latronax/2007/memobehr1991.jpg)
(http://img.photobucket.com/albums/v437/latronax/2007/openbabe1979.jpg)
(http://img.photobucket.com/albums/v437/latronax/2007/bossbabe1984.jpg)
(souped-down version of this Time Apparatus (http://www.diystompboxes.com/smfforum/index.php?topic=53452.0))
Quote from: puretube on March 26, 2007, 03:22:28 AM
fresh for Frankfurt:
(http://img.photobucket.com/albums/v437/latronax/2007/openbabe1979.jpg)
Cool, a fresh prototype from Messe and with a gut shot too!
I love the stacked boards! Nice use of header pins.
Do they conduct signals from one board to the other? Or are they structural?
Looking forward to your pics from Frankfurt. Coming soon?
Have a good show!
Puretube,
That's some awsome sounding clips, simply wild. I love the auto whammy going on there, is that your own design or is there a design out there where we can all use?
it`s the PCBs from reply#28 (http://www.diystompboxes.com/smfforum/index.php?topic=53452.msg416028#msg416028) in the other thread...
completely new (secret own) design...
yes they are connectors...
the modulated version gets a 3rd (control) PCB.
MusikMesse starts on wednesday - still gotta finish another box... :icon_wink:
love the mystery around it! Very cool pics!
OK, so back to my topic....
Does anyone see any problems in completing this project?
Can't see any problems, looks pretty cool. If I was doing it I'd add a option to have the delays in series as well as parallel.
Quote from: WelshWonder on March 25, 2007, 07:52:50 PM
In addition I want to have two LED's that blink on the repeats of both delay phases so I can visually check the timing.
That would be the difficult part. You'd have to somehow tap into the clock signal of each delay chip. I don't know if that's possible on a PT2399. It could be done if you use a different delay chip that uses a separate clock chip.
Quote from: d95err on March 26, 2007, 09:07:04 AM
Quote from: WelshWonder on March 25, 2007, 07:52:50 PM
In addition I want to have two LED's that blink on the repeats of both delay phases so I can visually check the timing.
That would be the difficult part. You'd have to somehow tap into the clock signal of each delay chip. I don't know if that's possible on a PT2399. It could be done if you use a different delay chip that uses a separate clock chip.
Actually, I found a cool topic on this site that will allow this function out of the PT2399, check it out --> http://www.diystompboxes.com/smfforum/index.php?topic=50185.0 (http://www.diystompboxes.com/smfforum/index.php?topic=50185.0)
Having two distinct delays on the same circuit board is apparently risky with respect to clock noise, especially with respect to heterodyning noise. Each clock frequency may well be high enough that any suitable filtering will easily tame it without detracting from bandwidth. Unfortunately, the sum and difference products (well, the difference, that is) may be substantially lower than the rolloff of the lowpass filters.
One way of getting around that is to use a single clock and clock frequency, and a combination of BBDs that can achieve multiple delay times. So here is a suggestion, place an MN3007 ahead of an MN3011, and gang them to the same master clock. The MN3007 (1024 stages) can produce a slapback delay of reasonable length and decent bandwidth. The MN3011 has 3328 stages and 6 different taps (at 396, 662, 1194, 1726, 2790, and 3328 stages). If you add 1024 stages to that, you get potential delays after 1420, 1686, 2218, 2750, 3814, and 4352 stages. That latter one can potentially be around 400msec with decent bandwidth, which isn't too shabby at all. If you install a pair of 6-position rotary switches, you can decide which tap (from 1 through 6) you want the first repeat and from which tap (2 through 7) you want the second repeat. Hell, install three such switches, and you can also determine which tap you want to feed to the regeneration loop.
This arrangement will nail you slapback plus longer delay, reasonable maximum delay time, NO heterodying, ONE clock, and ridiculous flexibility of delay stagger. The chips ain't cheap, but at around maybe $40-50 for all parts, that's actually a pretty decent return on investment if you can pull it off. Certainly nothing like it on the market AKAIK......well, until Mr. Barmentloo gets back from Musikmesse. :icon_wink:
with 2 serial delaylines @ 1 clock, you got 2 synchronized times of x-act half/double...
(without heterodyning at any frequency)
Mark: I`m not exhibiting myself this year, but bring some new design samples like every year for certain people. :icon_wink:
(wanted to show this off here, so 2 years from now no-one can claim it is based on s.th. posted here earlier...) :icon_smile:
I'm not absolutely certain I understand what you are suggesting (although I am absolutely certain that you are pressed for time at the moment and not able to spend a lot of time posting things). But here is what I think you mean.
If a person uses two identical high-capacity BBDs (like 2048, 3328, or 4096-stage devices), then one gets a delay time of exactly double the first chip at the output of the second.
The reason I suggested using an MN3011 is because the stagger between the first and second delay outputs can be adjusted without requiring a second clock. Of course, the first chip does not HAVE to be an 1024-stage MN3007. I only suggested it because it adds to the total number of stages, and because blanik said he was interested in a slapback and second delay. If a person was to use a pair of MN3011s in series, controlled by the same master clock, and could select the tap-point where the output of the first chip was directed to the second, plus the tap point where the output of the second came from....well....that would pretty much take up your entire summer vacation working through all the possibilities of all the delay staggers, wouldn't it? :icon_lol:
not to derail this interesting discussion but WelshWonder is planning on using PT2399s not BBDs.
Oops.
Then in the immortal words of Emily Littela: Never mind!
yes, I just thought: double (or half, just how you wanna name it) is a very nice musical/rhythmical interval...
(when you route it to 2 outputs...)
worx digi as well as ana.
digi can whine too, e.g. via the rails, btw...
Quote from: slacker on March 26, 2007, 12:11:05 PM
not to derail this interesting discussion but WelshWonder is planning on using PT2399s not BBDs.
Thanks, yeah, I want to use the PT2399's...
It's interesting to hear you discuss your ideas about delay so I am still all ears. However, I am not at that level yet where I can design my own schematics for new effect techniques (wish I could), so I have to work with what I already know (for the moment).
I did wonder about the noise problems using two identical delay designs and I wondered if that is best kept at bay by placing them serial or parallell configuration, although I will probably add a switch for this function.
I will be using the Rebote design and recreating a new layout so that the two circuits and the tempo LED indicator circuits are all on one board (this I am confident in doing). It is going to be a fair size enclosure but I think in the end it will be worth it, even if it is not the best sounding device, it will inevitably help me in improving my knowledge of effects construction.
Neat project idea.
With regards to noise issues, I'd say go for it, and worry about it only if it comes up. I think having seperate boards and power supply decoupling, and grounding them together at the power supply will be fine. Maybe use shielded wire for the input. But don't give up on your project before its started. I had two small clone boards hooked together every which way with clip leads a while back and was surprised to have no problems with heterodyning or whining.
Idea for your bypass: Forget true bypass, always have your signal going through the dry side of the delay mixer, and have two stompswitches to kill the two respective delay lines going into the mixer. Maybe use those switches to kill the repeats when its in bypass as well.
Is there a tempo LED possible (ie. easy)with the PTs?
Would it be possible to add an analog delay circuit in series or parallel with the pt2399 or would this just cause more problems?
Quote from: Processaurus on March 26, 2007, 08:45:36 PM
Is there a tempo LED possible (ie. easy)with the PTs?
It seems that it is
the ratio between the PT2399 frequency and the delay time is a relatively constant, at around 680000 to 690000, so all you need to is make a circuit to blind a LED every 685000 clock cycles
http://www.diystompboxes.com/smfforum/index.php?topic=50185.0 with a layout and everything